Res er voir prop er ties of the Up per Rotliegend and the Weissliegend sand stones (Perm ian) in the Zielona Góra Ba sin (west ern Po land)
Anna POSZYTEK1, *
1 In sti tute of Geo chem is try, Min er al ogy and Pe trol ogy, War saw Uni ver sity, ¯wirki i Wigury 93, 02-089 Warszawa, Po land
Poszytek A. (2014) Res er voir prop er ties of the Up per Rotliegend and the Weissliegend sand stones (Perm ian) in the Zielona Góra Ba sin (west ern Po land). Geo log i cal Quar terly, 58 (1): 193–206, doi: 10.7306/gq.1140
The Up per Rotliegend/Weissliegend sand stones in the Zielona Góra Ba sin are char ac ter ized by poorer res er voir prop er ties than in the cen tral part of the Pol ish Rotliegend Ba sin. How ever, there have been no de tailed stud ies of the rea sons for these dif fer ences. The main aim of this pa per is to in ter pret the fac tors that played a ma jor role in the dis tri bu tion of res er voir prop - er ties in the Zielona Góra Ba sin. Anal y sis of vari abil ity in res er voir prop er ties was per formed us ing po ros ity-depth, per me - abil ity-depth, and per me abil ity-po ros ity plots. The res er voir qual ity ra tio (RQ), cal cu lated by mul ti ply ing po ros ity and per me abil ity val ues, was also in tro duced. The RQ ra tio was found to be a use ful tool to dis tin guish six types of res er voir rocks. Anal y ses of the vari abil ity of res er voir prop er ties, cou pled with mi cro scopic ob ser va tions, were dis cussed in re la tion to the sed i men tary set ting of each type of rock. These sedimentological and pet ro graph i cal stud ies were in tended to de ter mine the vari abil ity of res er voir prop er ties with re spect to pri mary depositional or lithofacies ef fects and sec ond ary diagenetic ef - fects. The re sults in di cate that ce men ta tion was a ma jor fac tor con trol ling the dis tri bu tion of res er voir prop er ties, mainly by af fect ing the amounts of car bon ate, sul phate, and illite. Com pac tion had only a mi nor in flu ence on the res er voir prop er ties stud ied here.
Key words: Rotliegend, Weissliegend, Fore-Sudetic Monocline, res er voir prop er ties, res er voir qual ity ra tio (RQ).
INTRODUCTION
The Up per Rotliegend has been the main tar get of nat u ral gas ex plo ra tion in west ern Po land for over fifty years (e.g., P.
Karnkowski, 1999; Kwolek and Buniak, 2004; Wolnowski, 2004; Karnkowski, 2007; Kiersnowski et al., 2010a). Ex plo ra - tion has been fo cused on two re gions: the Zielona Góra Ba sin, lo cated south of Wolsztyn Ridge; and the Poznañ Ba sin, north of Wolsztyn Ridge (Fig. 1). Cur rently, ex plo ra tion is con cen - trated in the Poznañ Ba sin, and the larg est num bers of pub li ca - tions are from the Poznañ Ba sin on the Rotliegend sed i men ta - tion (Karnkowski, 1987, 1994; Buniak, 1999; Buniak et al., 1999; Pokorski and Kiersnowski, 1999; Szwarc and Kiersnowski, 1999; Kiersnowski and Buniak, 2006; Kiersnowski et al., 2010b), on pe trog ra phy (Rochewicz, 1980; Muszyñski and Rydzewska, 1986; Gregosiewicz and Protas, 1997;
Maliszewska and Kuberska, 2009), res er voir prop er ties and their re la tion ship to lithofacies (Such, 1996; Such et al., 2000;
Buniak et al., 2009), and ex plo ra tion of tight gas (Poprawa and Kiersnowski, 2008, 2010; Such et al., 2010). Sev eral pub li ca - tions re fer to the en tire Pol ish Rotliegend Ba sin and the Zielona Góra Ba sin (Kiersnowski, 1997; Karnkowski, 1999; Jarzyna et
al., 2009; Papiernik et al., 2010); how ever, there are no de tailed pub li ca tions on the Zielona Góra Ba sin.
The Poznañ Ba sin, lo cated in the cen tral part of the Pol ish Rotliegend Ba sin, is char ac ter ized by large thick nesses of the Up per Rotliegend, ex ceed ing 2 km, and a large con tri bu tion of ae olian sand stones in the sec tion. In the Zielona Góra Ba sin, lo - cated in the mar ginal part of the ba sin, the thick ness of the Rotliegend does not ex ceed 1000 m, and the con tri bu tion of aeolianites in the sec tion de creases to wards the west in fa vor of flu vial sand stones.
Ae olian sand stones are the main res er voir rock for gas ac - cu mu la tion, but the res er voir prop er ties in the two ar eas are con sid er ably dif fer ent (Poszytek, 2006; Jarzyna et al., 2009;
Papiernik et al., 2010). The res er voir prop er ties in the Poznañ Ba sin are much better than in the Zielona Góra Ba sin. In the Poznañ Ba sin, ae olian sand stones are char ac ter ized by very good res er voir prop er ties (po ros ity >20% and per me abil ity
>1000 mD) and form a wide zone in the cen tral part of the ba sin.
Pre vi ous stud ies (Buniak et al., 2009) in di cated that the de - crease in the po ros ity and per me abil ity val ues of ae olian sand - stones to the south and north in the Poznañ Ba sin is linked with the oc cur rence of flu vial de pos its near Wolsztyn Ridge or with the larger sub si dence of the Rotliegend, which is in turn con - nected with more in tense com pac tion of ae olian sand stones.
In the Zielona Góra Ba sin, ae olian sand stones are less fre - quent in the suc ces sion, and their res er voir prop er ties are of ten half those of the ae olian sand stones from the Poznañ Ba sin.
These sand stones are also char ac ter ized by a patchy lat eral dis tri bu tion of po ros ity and per me abil ity val ues, which is re -
* E-mail: anna.poszytek@uw.edu.pl
Received: July 7, 2013; accepted: December 31, 2013; first published online: December 31, 2013
flected in the close prox im ity of sec tions with good res er voir prop er ties (po ros ity >15%, per me abil ity >100 mD) and poor res er voir prop er ties (po ros ity <5%, per me abil ity <1 mD). In ad - di tion, in sand stones from the Zielona Góra Ba sin, high po ros ity is not nec es sar ily col lo cated with high per me abil ity, which re - sults in dif fi culty in de ter min ing the lat eral zones with the most pos i tive res er voir prop er ties.
Cur rently, the Zielona Góra Ba sin is con sid ered a re gion of poor pros pects for gas-field dis cov er ies (Wolnowski, 2004).
Among the rea sons for this are the poor res er voir prop er ties of the sand stone and the patchy lat eral dis tri bu tion of res er voir prop er ties. How ever, there have been no com plex stud ies that ex plained this vari abil ity in res er voir prop er ties. It should be noted that over 100 bore holes were drilled in the Zielona Góra Ba sin from the 1970’s to the 1990’s, and huge amounts of geo - log i cal in for ma tion were col lected: cores, thin sec tions, and lab - o ra tory mea sure ments of po ros ity and per me abil ity. Hence, the Zielona Góra Ba sin is still an ex cel lent test ing ground for anal y - sis of res er voir prop er ties on a re gional scale. The main aim of this pa per is to in ter pret the fac tors that played a ma jor role in the dis tri bu tion of res er voir prop er ties in the Zielona Góra Ba - sin. The anal y ses de scribed here are based on re in ter pre ta tion of ar chi val data us ing mod ern knowl edge.
GEOLOGICAL SETTING
The South Perm ian Ba sin sys tem is lo cated in West ern and Cen tral Eu rope, ex tend ing from Great Brit ain to Po land, and is one of the main re gions for gas ex ploi ta tion (Glen nie, 1990;
Ziegler, 1990; Karnkowski, 1999; Doornenbal and Stevenson, 2010). The gas plays con sist of un der ly ing source rock in Car - bon if er ous sed i ments. The South Perm ian Ba sin sys tem is di - vided into sev eral sub-bas ins, of which one is the Pol ish Perm - ian Ba sin, lo cated in the east ern part of the over all ba sin sys - tem. The Pol ish Perm ian Ba sin was de vel oped mostly by post-Variscan dextral trans-ten sion (Nikishin et al., 2002;
Lamarche and Scheck-Wenderoth, 2005). The south ern Perm - ian (Rotliegend) Ba sin is filled with Lower Rotliegend (Autunian) sed i men tary and vol ca nic rocks, and even in some places af fil i - ated with the Rotliegend, Up per Car bon if er ous (Stefanian in age) red beds and vol ca nic rocks, as well as Up per Rotliegend clastic de pos its. Sed i men ta tion of the Up per Rotliegend rocks took place un der arid and semi-arid con ti nen tal con di tions, and there fore the ba sin con tains ae olian, flu vial, and playa de pos its.
Dis tri bu tion of fa cies and their thick ness in the Up per Rotliegend Ba sin was con trolled by the Wolsztyn Ridge, a tec -
194 Anna Poszytek
Fig. 1. Maps of the Pol ish Up per Rotliegend Ba sin
A – map of thick ness, B – map of res er voir fa cies dis tri bu tion (af ter Kiersnowski in Doornenbal and Stevenson, 2010)
tonic horst, which dur ing the sed i men ta tion of the Up per Rotliegend was the source area for flu vial sed i ments (Karnkowski, 1987, 1994; Weihe, 1997; Kiersnowski et al., 2010b). The Wolsztyn Ridge sep a rated the south ern part of the Rotliegend Ba sin into two parts: the north ern Poznañ Ba sin and the south ern Zielona Góra Ba sin (Fig. 1). The Poznañ Ba sin is lo cated in the cen tral part of the Pol ish Ba sin and is char ac ter - ized by large thick nesses of the Up per Rotliegend, ex ceed ing 2 km, and a con tri bu tion of ae olian sand stones in the sec tion.
The Zielona Góra Ba sin is lo cated on the SW mar gin of the Pol - ish Ba sin; the thick ness of the Rotliegend does not ex ceed 1000 m, and the con tri bu tion of aeolianites in the sec tion de - creases to wards the west (Fig. 1B). Con ti nen tal Rotliegend sed i men ta tion was ter mi nated by the Zechstein trans gres sion, which caused par tial redeposition of poorly con sol i dated, po - rous, and per me able ae olian sands and loss of col our in the top most part of the sec tion. Bleached Rotliegend ae olian or flu - vial sand stones and shal low-ma rine sand stones be low the Kupferschiefer are as signed to the Weissliegend (Jerzykiewicz et al., 1976; Nemec and Porêbski, 1977; Glen nie et Bull er, 1983; Karnkowski, 1986; Michalik, 2000, 2001; Kiersnowski, 2007). They are topped with the Zechstein Lime stone de pos its (Peryt et al., 2012) and then by the PZ1 evaporites (Wag ner and Peryt, 1997; Kotarba et al., 2006).
Sand stones of the Zielona Góra Ba sin be long to the Drawa and Noteæ for ma tions (Fig. 2) and they are ae olian and flu vial or i - gin. The Noteæ For ma tion sand stones are cov ered by shal - low-ma rine Weissliegend sand stones. Nu mer ous con ven tional gas res er voirs have been rec og nized in Po land within the po rous and per me able ae olian sand stones (Fig. 1B) sealed by
Zechstein evaporites and im per me able claystones, both in the Poznañ and Zielona Góra bas ins (P. Karnkowski, 1999; Kwolek and Buniak, 2004; Wolnowski, 2004; Karnkowski, 2007;
Kiersnowski et al., 2010a).
METHODOLOGY
The study was per formed us ing data from bore holes drilled in the Zielona Góra Ba sin. Bore holes were se lected from those hav ing suf fi cient geo log i cal in for ma tion: cores, thin sec tions, and lab o ra tory mea sure ments of ef fec tive po ros ity and hor i zon - tal per me abil ity. In the first stage of the study, a mac ro scopic de scrip tion of the cores was gen er ated: the lithofacies were de - scribed, and the depositional en vi ron ment of the rocks un der study was in ter preted. Next, a mi cro scopic anal y sis of 31 thin sec tions from dif fer ent depositional en vi ron ments was per - formed. The min eral com po si tion of the grain frame work, de - gree of grain sort ing, inter gra nu lar con tacts, and ce ments, as well as the char ac ter and value of po ros ity, were de scribed.
These sedimentological and pet ro graph i cal stud ies were in - tended to de ter mine the vari abil ity of res er voir prop er ties with re spect to pri mary depositional or lithofacies ef fects and sec - ond ary diagenetic ef fects. Then an anal y sis of 1230 po ros ity and per me abil ity mea sure ments was car ried out. Mea sure - ments of po ros ity and per me abil ity were col lected from sand - stones of dif fer ent or i gins, lithologies, and depths of oc cur - rence. These in ves ti ga tions aimed to es tab lish re la tion ships be - tween po ros ity and depth, per me abil ity and depth, and per me - abil ity and po ros ity. The res er voir qual ity ra tio (RQ), cal cu lated Fig. 2. Strati graphic cross-sec tion through the Pol ish part of the Rotliegend South ern Perm ian Ba sin
(af ter Kiersnowski in Doornenbal and Stevenson, 2010)
196 Anna Poszytek
Fig. 3. Lithofacies of the Up per Rotliegend sand stones in the Zielona Góra Ba sin
A – sche matic pro file; B – shal low-ma rine sand stones; C – ae olian sand stones; D – flu vial sand stones; Sm – mas sive sand stones, Sh – sand stones with hor i zon tal bed ding, Sx – sand stones with cross-bed ding, Sr – sand stones with rip ple bed ding;
for lithofacies code see Ta ble 1
by mul ti ply ing po ros ity and per me abil ity val ues, was also in tro - duced. The RQ ra tio en ables clas si fi ca tion of res er voir rocks.
Un til now, no anal y sis of res er voir prop er ties had been per - formed us ing the RQ ra tio.
SEDIMENTOLOGICAL AND PETROGRAPHIC CHARACTERISTICS
Sand stones were formed in three types of sed i men tary set - tings: flu vial, ae olian and shal low-ma rine en vi ron ments were noted in the study area (Fig. 3). Flu vial rocks oc cur in the lower parts of the pro files through out the study area. They are de vel - oped as sand stones and con glom er ates (Fig. 3). In ad di tion, flu - vial sand stones dom i nate pro files in the west ern part of the area and near Wolsztyn Ridge (up to sev eral hun dred metres thick).
Ae olian sand stones oc cur in the up per parts of the pro files and dom i nate in the east ern and south ern parts of the area. Their thick ness in creases to wards the east (up to sev eral hun dred metres). In the cen tral part of the ba sin, a zone oc curs with lat eral al ter na tion of ae olian and flu vial sand stones. These ae olian and flu vial sand stones are cov ered with Weissliegend sand stone (to sev eral metres). De pend ing on fa cies and pe trog ra phy, the sand stones can be char ac ter ized by their par tic u lar res er voir prop er ties. The fa cies clas si fi ca tion was based on a mod i fied ver sion of the code pro posed by Miall (1978; Ta ble 1).
Flu vial sand stones in clude sand stones formed in the chan nel and interchannel parts of the flood plain (Fig. 3 and Ta - ble 1). Over-bank fa cies and those formed dur ing floods are char ac ter ized by poor sort ing and mas sive struc ture of the sand stone-con glom er atic fa cies (Sm1) and a rip pled struc ture in the case of sand stone-siltstone fa cies (Sr). Chan nel de pos its are char ac ter ized by better sort ing than over-bank fa cies and a dis tinct hor i zon tal or cross-strat i fi ca tion (Sx1). The thick ness of the flu vial de pos its reaches 100 m, and they dom i nate in the lower part of the an a lyzed sec tions. Flu vial fa cies have also been noted as sev eral-me ter-thick in ter ca la tions within ae olian de pos its in the up per parts of the sec tions (Fig. 3). In this case, they are rep re sented by poorly sorted mas sive sand stones (Sm1) with a dis tinct ero sional lower bound ary. These de pos its re flect the de vel op ment of a wadi-type river net work within the dune field.
Ac cord ing to the clas si fi ca tion of Pettijohn et al. (1972), the flu vial lithofacies in clude lithic and sublithic arenites (Fig. 4).
The grains are char ac ter ized by poor sort ing. These lithofacies are char ac ter ized by the pres ence of much larger quartz grains in com par i son to rock clasts and feld spars (Fig. 5B), which is linked to the better re sis tance of quartz grains to dis in te gra tion dur ing flu vial trans port. The rock clasts in clude mainly vol ca nic rocks from ero sion of the Wolsztyn Ridge. The grains are densely packed, and the inter gra nu lar con tacts are point or pla - nar, in di cat ing phys i cal com pac tion. The frame work of ten con - tains ma trix and car bon ate ce ment (Fig. 6C), which fills it partly or com pletely, re sult ing in a de crease in ef fec tive po ros ity.
Ae olian sand stones in clude well-sorted and dis tinctly bed - ded sand stones up to sev eral hun dred metres thick (Fig. 3 and Ta ble 1). They con tain a sev eral-me ter-thick packet of high-an - gle cross-strat i fied sand stones (Sx2), ev i denc ing a dune set ting.
Dune sand stones also in clude mas sive sand stones and silty Lithofacies
code De scrip tion In ter preted en vi ron ment
Sx1 cross-bed ded sand stones, me dium- to coarse-grained,
poor sorted, thick ness from 2 up to 10 m channel
flu vial Sr rip ple-lam i nated silty sand stones, fine- to
coarse-grained, poorly sorted, thick ness to few metres over-bank Sm1 mas sive sand stones, me dium- to coarse-grained, poor
sorted, with fine peb bles, thick ness from 0.5 up to 15 m flood Sx2 high-scale cross-bed ded sand stones, fine- to me -
dium-grained, well-sorted, thick ness up to 30 m dune
ae olian Sh1 plane-bed ded sand stones, me dium- to coarse-grained,
well-sorted, thick ness from 0.5 up to 10 m interdune or sand sheet Sm2
mas sive sand stones of ten with bioturbation and rare fos - sils, fine- to me dium-grained, well-sorted, ce mented by
cal cite, thick ness from 2 up to 15 m
redeposition of un con sol i dated ae olian sands dur ing ma rine transgression
shal low- ma rine Sh2
plane-bed ded sand stones, fine- to me dium-grained, lam i nated by thin clay lay ers, ce mented by cal cite,
thick ness from 0.5 to 2 m shal low-ma rine
T a b l e 1 Lithofacies clas si fi ca tions and de scrip tions (mod i fied from Miall, 1978)
Fig. 4. The min eral com po si tion of skel e tal grains of sand stones in the clas si fi ca tion di a gram QFL of Pettijohn et al. (1972)
198 Anna Poszytek
Fig. 5. Mi cro scopic im ages of sand stones
A – ae olian, B – flu vial, C – shal low-ma rine; Ca – car bon ate ce ments, F – feld spars, Fe – haematite coat ings, L – lithoclasts, Q – quartz
Fig. 6. Mi cro scopic im ages of ce ment fill ing inter gra nu lar space
A – quartz coat ings and car bon ate ce ments; B – ferruginous coat ings and illite ce ments; C – car bon ate ce ments; D – quartz coat ings and anhydryte ce ments; An – anhydrite, Ca – car bon ates,
Fe – haematite coat ings, Il – illite, Q – quartz coat ings
sand stones with hor i zon tal bed ding (Sh1), from 0.5 m to sev eral metres thick, which were formed in de pres sions be tween the dunes. Hor i zon tally bed ded sand stones with thick nesses ex - ceed ing sev eral metres have been in ter preted as sand stones formed within sand sheets.
Ac cord ing to the clas si fi ca tion of Pettijohn et al. (1972), ae - olian sand stones in clude quartz and sublithic and subarkosic arenites (Fig. 4). The pres ence of sublithic and subarkosic arenites in ae olian fa cies may be caused by interfingering of ae - olian and flu vial en vi ron ments, which could have caused the redeposition of non-con sol i dated par ti cles of flu vial or i gin (feld - spars and rock frag ments) into ae olian sands dur ing arid pe ri - ods (Kiersnowski, 1997; Sweet, 1999). Ae olian lithofacies are char ac ter ized by the best grain sort ing and the high est po ros ity among all Rotliegend sand stone lithofacies (Fig. 5A). High po - ros ity is ac com pa nied by low ce ment con tent, mainly in the form of clay-haematite grain coat ings and rare quartz coat ings on the quartz grains (Fig. 6A, B). How ever, a large part of the ae olian sand stones is char ac ter ized by in tense ce men ta tion by car bon - ate and sul phate min er als as well as illite (mesh work illite;
Gaupp, 1997), which con sid er ably de creases pri mary po ros ity and per me abil ity (Fig. 6B). Based on stud ies in the Zielona Góra Ba sin (Michalik, 1996) and in the Poznañ Ba sin (Maliszewska, 1997; Maliszewska and Kuberska, 2009), it is as sumed that illite crystallisation took place in the Ju ras sic, prob a bly dur ing hy dro ther mal events re lated to tec tonic ac tiv ity (Maliszewska and Kuberska, 2009). Iso to pic stud ies from Ger - many (Gaupp et al., 1993; Zwingmann et al., 1998), the Neth er - lands (Gaupp and Okkerman, 2011), and the North Sea (Gluyas and Leon ard, 1995) show re sults sim i lar to those from Po land (Maliszewska and Kuberska, 2009). This in di cates that the illite ce men ta tion pro cess was a re gional hy dro ther mal phe - nom e non. There fore, at least un til that time, the de pos its were char ac ter ized by high per me abil ity. In turn, the car bon ate and sul phate ce ments could be early as well as late diagenetic (Kuberska, 2004). How ever, the late diagenetic car bon ate and sul phate ce ments oc cur ring in the deeper parts of the sec tions did not re strict po ros ity to the same ex tent as the early diagenetic ce ments oc cur ring in the top most parts of the sec - tions (Fig. 6D).
Dis so lu tion of un sta ble frame work grains (feld spars and vol ca nic rock frag ments) was found in the rocks un der study.
This phe nom e non, how ever, is not com mon. In place of the dis - solved par ti cles, low sec ond ary po ros ity oc curs within the clay res i due. How ever, sec ond ary po ros ity is low and does not im - pact over all po ros ity.
Shal low-ma rine sand stones in clude mas sive and hor i - zon tally bed ded sand stones, of ten with bioturbations and siltstone in ter ca la tions, which oc cur in the top most parts of the sec tions (Fig. 3 and Ta ble 1). Mas sive sand stones (Sm2) were formed due to redeposition of non-con sol i dated, pri mar ily ae - olian sand stones dur ing the ini tial phases of the Zechstein trans gres sion. These mas sive, tran si tional sand stones pass grad u ally into typ i cal shal low-ma rine sand stones: lam i nated (Sh2) and mas sive with bioturbations (Sm2). Mi cro scopic stud - ies have shown that ac cord ing to the clas si fi ca tion of Pettijohn et al. (1972), the sand stones rep re sent quartz and sublithic and subarkosic arenites, sim i larly to the ae olian de pos its (Fig. 4).
They are char ac ter ized by a high con tent of car bon ates and sul - phate ce ments, which re strict the high pri mary po ros ity (Fig. 5C). Sand stones with a large con tent of car bon ates and sul phate ce ments are char ac ter ized by the prev a lence of point types of inter gra nu lar con tacts, which sug gests an in sig nif i cant con tri bu tion from com pac tion and the early diagenetic char ac - ter of the ce ment, which ac tu ally pre vented com pac tion. In sand stones with low car bon ate and sul phate ce ment con tents,
the inter gra nu lar con tacts are point and pla nar, in di cat ing phys i - cal com pac tion dur ing burial of these rocks.
VARIABILITY OF RESERVOIR PROPERTIES
The vari abil ity of po ros ity and per me abil ity has been de - scribed by the re la tion ships of po ros ity and per me abil ity to depth and the re la tion ship of per me abil ity to po ros ity. The de te - ri o ra tion of the res er voir prop er ties of clastic rocks with depth is caused by sed i ment com pac tion and re duc tion of pore space, which re stricts po ros ity and de creases per me abil ity (Tiab and Donaldson, 2004). How ever, the mag ni tude of com pac tion in sand stone de pends not only on the burial his tory, but also on the min eral com po si tion of the grain frame work, its sort ing and round ing, and the pres ence of ma trix and early diagenetic ce - ments (Beard and Weyl, 1973; Houseknecht, 1987; BjÝrlykke et al., 1989; Hogg et al., 1996; Amthor and Okkerman, 1998). The in flu ence of the re main ing fac tors is very clearly vis i ble in the Rotliegend sand stones from the Zielona Góra Ba sin, where there is no di rect re la tion ship be tween po ros ity and per me abil ity re duc tion and depth within the de scribed sed i men tary set tings (Fig. 7).
No dis tinct trends of po ros ity and per me abil ity de crease with depth were found within the flu vial de pos its (Fig. 7). Most prob a bly, lo cal fac tors in flu enc ing the li thol ogy of these de pos - its, such as sort ing or the pres ence of ma trix, ex erted more con - trol over the res er voir prop er ties of flu vial sand stones than did burial pro cesses.
In ae olian sand stones, po ros ity and per me abil ity change abruptly with depth, a phe nom e non which is par tic u larly dis tinct in dune de pos its (Fig. 7). This is prob a bly linked with lo cal vari - abil ity in sam ple li thol ogy (e.g., con tent of illite ce ments in the pore space).
The shal low-ma rine Weissliegend sand stones gen er ally show a de crease of po ros ity and per me abil ity with depth. How - ever, the same sand stones are char ac ter ized by higher res er - voir prop er ties than the sam ples col lected as de scribed above (Fig. 7). The max i mum val ues of po ros ity and per me abil ity are found in sand stones that did not un dergo full ce men ta tion by car bon ate and sul phate min er als, which made their po ros - ity/per me abil ity and hence res er voir qual ity sim i lar to those of ae olian sand stones. The lack of early diagenetic ce ment re - sulted in a sus cep ti bil ity to com pac tion that re stricted pri mary po ros ity.
The next stage of the study was to ana lyse the charts show - ing the re la tion ships of per me abil ity to po ros ity (Fig. 8), which made it pos si ble to trace the re la tion ships of po ros ity and per - me abil ity changes and to dis cuss which fac tors be sides com - pac tion could have caused de vi a tions from the gen eral trend (Ei ther and King, 1991; Cade et al., 1994; Ev ans et al., 1997).
In the case of ae olian de pos its, the dune sand stones, which are po ten tially the most fa vor able res er voir rocks with the best qual i ties, do not form iso lated fields, but are mixed with sand - stones from the interdune ar eas and sand sheets (Fig. 8). The res er voir prop er ties of ae olian sand stones from the Zielona Góra Ba sin are highly vari able. Sand stones with po ros ity be low 15% and per me abil ity of 1 mD (Fig. 8A, type A) oc cur in the top - most parts of the sec tions, where dur ing the Zechstein trans - gres sion, in fil tra tion and ce men ta tion of the pore space by car - bon ate and sul phate min er als took place. In con trast, ae olian sand stones with po ros ity >15% and per me abil ity <1 mD (Fig. 8A, type B) rep re sent sand stones in which the pore space is com pletely filled with mesh work illite or silty sand stones from the interdune ar eas. Most mea sure ments in the ae olian sand -
stones point to a per me abil ity from 0.1 mD to al most 100 mD at a very wide range of po ros i ties (from 3 to 20%; Fig. 8A, type C).
This phe nom e non can be caused by a num ber of fac tors, which of ten act in de pend ently, such as sort ing, com pac tion, and type of ce ments and how they fill the pore space (Ei ther and King, 1991; Cade et al., 1994; Ev ans et al., 1997). The last group of dune sand stones is char ac ter ized by very good res er voir prop - er ties (po ros ity >15%, per me abil ity >100 mD; Fig. 8A, type D) and in clude well-sorted sand stones with a small con tri bu tion of ce ment in the pore space.
Flu vial sand stones are char ac ter ized by less fa vor able res - er voir prop er ties than ae olian sand stones (Fig. 8). Sand stones with very poor res er voir prop er ties (po ros ity <10% and per me - abil ity <0.01 mD – Fig. 8B, type A) are dom i nant. They are rep - re sented by poorly sorted sand stones, of ten con glom er atic, with a high con tent of ma trix in the pore space. The next group of flu vial sand stones is char ac ter ized by per me abil ity within the 0.0110 mD range and a very wide dis per sion of po ros i ties, 2–20% (Fig. 8B, type B). This can be caused by a num ber of fac tors, such as grain sort ing, ma trix con tent, and com pac tion in ten sity (Ei ther and King, 1991; Cade et al., 1994; Ev ans et al., 1997). High res er voir prop er ties with po ros ity >15% and per me - abil ity >10 mD (Fig. 8B, type C) oc cur in well-sorted sand stones with a small con tri bu tion of ma trix in the pore space, which were de rived from the redeposition of ae olian sand stones dur ing the de vel op ment of wa dis in the dune fields.
Two groups of rocks can be dis tin guished in the shal - low-ma rine sand stones. The first has very poor res er voir prop - er ties (per me abil ity <1 mD and po ros ity of only a few per cent;
Fig. 8C, type A). The sec ond group ex hib its a dis tinct trend in the per me abil ity-to-po ros ity re la tion ship (Fig. 8C, type B). The first group in cludes clayey sand stones formed un der shal - low-ma rine con di tions, in which com pac tion and ce men ta tion have sig nif i cantly re stricted the res er voir prop er ties. The sec - ond group in cludes sand stones formed due to redeposition of dune sands. Their res er voir prop er ties have been in flu enced by ce men ta tion by car bon ate and sul phate min er als. There fore, de pend ing on the con tri bu tion of ce ment in the pore space, their po ros ity and per me abil ity val ues change pro por tion ally: po ros - ity within 218% and per me abil ity within 0.11000 mD. Note that the high est po ros ity val ues in the shal low-ma rine de pos its are lower than the high est po ros ity val ues in the ae olian sand - stones. The rea son for this lies in par tial ce men ta tion, com pac - tion, or both, in which lack of ce ment can cause re duc tion of po - ros ity. This fact is also ev i denced by charts show ing the re la - tion ships of po ros ity and per me abil ity to depth.
These char ac ter is tics in di cate that the Rotliegend and Weissliegend sand stones from the Zielona Góra Ba sin ex hibit wide vari abil ity in res er voir prop er ties which is not cor re lated with sed i men tary con di tions. There is also no cor re la tion be - tween per me abil ity and po ros ity, which causes dif fi culty in de - ter min ing the zones with the high est res er voir qual ity. There -
200 Anna Poszytek
Fig. 7. Graphs show ing the re la tion ship of po ros ity and per me abil ity with depth for the Rotliegend and Weissliegend sand stones from the Zielona Góra Ba sin
A – re la tion ship of po ros ity with depth; B – re la tion ship of per me abil ity with depth
fore, an at tempt was made to clas sify the res er voir prop er ties and to de scribe the most im por tant fac tors in flu enc ing the pres - ence of zones with high est and low est res er voir qual ity.
CLASSIFICATION OF RESERVOIR PROPERTIES
In prac tice, a com monly used co ef fi cient is the FZI (Flow Zone In di ca tor; Corbett and Pot ter, 2004; Ba³a and Jarzyna, 2004) that uses the Kozeny-Carman for mula (Tiab and Donaldson, 2004) based on the re la tion ship of per me abil ity to po ros ity. This in di ca tor makes it pos si ble to rec og nize rocks with sim i larly de vel oped pore space, as de ter mined by their or i - gin and sim i lar diagenetic pro cesses. How ever, in the case of the Rotliegend and Weissliegend sand stones from the Zielona Góra Ba sin, this task is very dif fi cult due to the com plex or i gin (ae olian, flu vial, and shal low-ma rine sand stones) and diagenesis of the rocks un der study (com pac tion, ce men ta tion by fer rit ic illite, car bon ate, and sul phate min er als, where each of these pro cesses took place at a dif fer ent time and with dif fer ent in ten sity). There fore, to clas sify the res er voir rocks, the res er - voir qual ity ra tio (RQ) has been in tro duced here, which is cal cu - lated by mul ti ply ing the mea sured po ros ity in a given sam ple [%] by the per me abil ity [mD]:
RQ ra tio = po ros ity [%] ´ per me abil ity [mD]
The RQ ra tio does not char ac ter ize any phys i cal prop erty of the rock, but is the value of its res er voir qual ity and is used to char ac ter ize, not the pore space, but the res er voir prop er ties, i.e., the ca pa bil ity of the de pos its un der study to col lect and con - duct flu ids.
Fol low ing the clas si fi ca tion of Levorsen (1967), who sub di - vided res er voir rocks us ing po ros ity and per me abil ity val ues, six types of res er voir rocks based on the RQ ra tio have been dis tin guished in this re search (Fig. 9). The bound aries be tween the rock types are oblique to the gen eral trend of the per me abil - ity-po ros ity re la tion ship and change logarithmically, sim i larly to the val ues of the per me abil ity co ef fi cient, which largely de ter - mines the RQ ra tio:
1. Type I: RQ (po ros ity ´ per me abil ity) 1 – “tight” rocks;
2. Type II: RQ (1–10) – rocks with very low res er voir qual ity;
3. Type III: RQ (10–100) – rocks with low res er voir qual - ity;
4. Type IV: RQ (100–1000) – rocks with me dium res er - voir qual ity;
5. Type V: RQ (1000–10,000) – rocks with high res er - voir qual ity;
6. Type VI: RQ > 10,000 – rocks with very high res er voir qual ity.
The dis tri bu tion of the RQ ra tio is pre sented in the chart show ing the re la tion ship be tween po ros ity and per me abil ity for all Rotliegend and Weissliegend sand stones from the Zielona Góra Ba sin. It makes it pos si ble to dis tin guish rocks with high and very high res er voir qual ity – classes 5 and 6 (rocks with po - ros ity above 15% and per me abil ity above 100 mD), linked with
Fig. 8. Graphs show ing the re la tion ship of per me abil ity to po ros ity with re gard to par tic u lar sed i men tary con di tions
A – re la tion ship of per me abil ity to po ros ity for ae olian sand stones;
B – re la tion ship of per me abil ity to po ros ity for flu vial sand stones;
C – re la tion ship of per me abil ity to po ros ity for shal low-ma rine sand stones
ae olian sed i men ta tion or redeposition of dune sands, char ac - ter ized by good sort ing and low ce ment con tent in the pore space. On the op po site side are rocks of class 1 – “tight” rocks, for which per me abil ity falls be low 0.11 mD and po ros ity is slightly above 10%. These are sand stones with a high con tent of ce ment, ma trix, or both in the pore space, which sig nif i cantly re stricts per me abil ity. In the re main ing classes (2, 3 and 4), po - ros ity val ues are widely dis persed. This phe nom e non is caused by a num ber of fac tors which de pend on the or i gin of rocks and the diagenetic pro cesses to which they have been sub jected.
This is re flected as grain sort ing, ma trix and ce ment con tent, and com pac tion in ten sity (Ei ther and King, 1991; Cade et al., 1994; Ev ans et al., 1997). The var i ous fac tors af fect ing po ros ity and per me abil ity are dif fi cult to sep a rate from each other and rep re sent the dom i nant fac tors af fect ing res er voir prop er ties.
How ever, it can be as sumed that a po ros ity of less than 10%
and a per me abil ity >10 mD is re lated to an in crease in grain size. A po ros ity >10% and a per me abil ity <10 mD can be as so - ci ated with the oc cur rence of microporosity as so ci ated with the pres ence of illite in the inter gra nu lar pore space.
The vari abil ity of the RQ ra tio has also been shown on the map with the mean value of the RQ ra tio in the top most (50 m) in ter val of the Rotliegend and Weissliegend (Fig. 10). This in ter - val con tains most of the gas res er voirs in the area, and there - fore it is usu ally al most fully cored and very well-rec og nized.
The map was com piled based on cores with sedimentological and petrographic anal y ses as well as data from other bore holes in the study area avail able in the PGNiG ar chives. The mean value of the RQ ra tio was de ter mined for each bore hole for the top most 50 m of the Rotliegend in ter val, and a map of its dis tri - bu tion was com piled.
The map shows that the cen tral part of the Zielona Góra Ba - sin con tains rocks of me dium res er voir qual ity linked with ae - olian rocks, which to the north, south, and west pass into rocks of very low res er voir qual ity and into “tight” rocks. To the north and west, re duc tion of res er voir prop er ties is linked to the ap - pear ance of flu vial sand stones with high ma trix con tent in the pore space. The de crease of res er voir prop er ties to the south is linked to in tense ce men ta tion of ae olian sand stones with mesh -
work illite. Within the zone with me dium res er voir prop er ties (prev a lence of ae olian fa cies) oc cur iso lated, small ar eas with high res er voir qual ity which of ten lie ad ja cent to ar eas with low res er voir prop er ties. The rea son for this may be the pres ence of nu mer ous synsedimentary faults in the Rotliegend de pos its (Fig. 10), which could pro vide a path for fluid mi gra tion and ce - men ta tion of ae olian sand stones. How ever, there is no clear ev - i dence for a link be tween the struc tural po si tion of sand stones and the RQ ra tio (Fig. 10). So far, de tailed study of this prob lem has not been car ried out in Po land.
To ex plain this patchy dis tri bu tion of res er voir qual ity, the RQ ra tio was in ter preted with re gard to sed i men tary con di tions and mi cro scopic ob ser va tions. The tri an gle graph rep re sent ing the per cent age con tri bu tion of par tic u lar sed i men tary con di - tions in the sec tions un der study (Fig. 11) in di cates that the value of the RQ ra tio is not strictly linked with rock or i gin. How - ever, anal y sis of the RQ ra tio in re la tion to mi cro scopic ob ser va - tions gave a clearer cor re la tion. The chart show ing the per cent - age con tent of clay (ma trix and/or mesh work illite), chem i cal ce - ments (car bon ates and sulphates), and pores not filled with ce - ment in di cates that ce men ta tion was the main fac tor de ter min - ing res er voir prop er ties (Fig. 12). Early diagenetic ce men ta tion by car bon ate and sul phate min er als, which dras ti cally de - creases the res er voir qual ity of the sand stones un der study, was par tic u larly im por tant. Late diagenetic ce men ta tion by illite or the pres ence of ma trix in the pore space caused po ros ity and per me abil ity to de crease, but did not cause an ex treme re duc - tion, as in di cated by rel a tively high res er voir clas si fi ca tions of 2 and 3.
The pres ence of illite in the pore space is mostly af fected by the RQ ra tio of ae olian sand stones. The fact that not all ae olian sand stones are ce mented by illite is an im por tant is sue. More - over, ce men ta tion in ten sity var ies from a few per cent to sev eral per cent. This in di cates that the illite ce men ta tion pro cess could be se lec tive, mul ti stage, or both. Stud ies of illite in Rotliegend ae olian sand stones in Ger many in di cated that illite crystallisation is mul ti stage and de pend ent on the pres ence of tec tonic horst and trough (Zwingmann et al., 1998). Pre vi ous min er al og i cal stud ies of illites in the Pol ish Rotliegend Ba sin in -
202 Anna Poszytek
Fig. 9. Chart show ing the re la tion ship be tween per me abil ity and po ros ity with: A – bor ders of classes of res er voir rocks dis tin guished by the RQ ra tio; B – sam ple di vided into classes based on res er voir qual ity ra tio (RQ)
di cated that crystallisation of illite could be re lated to tec tonic ac tiv ity dur ing the Ju ras sic pe riod (Maliszewska and Kuberska, 2009). How ever, the ef fects of tec tonic ac tiv ity in the mul ti stage crystallisation of illite have not been in ves ti gated in the Pol ish Rotliegend Ba sin, and this re mains a topic for fu ture re search.
DISCUSSION
Sand stones from the Zielona Góra Ba sin and the Poznañ Ba sin are char ac ter ized by dif fer ent res er voir prop er ties and dif fer ent dis tri bu tions. This is due to the dif fer ent sed i men tary con di tions and diagenetic pro cesses dur ing burial in the two ar - eas. There fore, re sults from the Poznañ Ba sin can not be di - rectly used in the Zielona Góra Ba sin.
The re sults ob tained did not con firm that burial pro cesses were the main fac tor dif fer en ti at ing res er voir prop er ties in the Zielona Góra Ba sin. Prob a bly, lo cal fac tors in flu enc ing sand - stone li thol ogy, such as min eral com po si tion of the grain frame - work, grain sort ing, or pres ence of ma trix, ex erted more con trol over the res er voir prop er ties of sand stones than burial pro - cesses.
Of ten sand stones oc cur ring in the lower parts of the pro files were more com pacted. It should be noted that the sand stone li - thol ogy of the lower parts of the pro files is dif fer ent from that of the sand stones oc cur ring above them. This ap plies to both ae - olian and flu vial sand stones.
Ae olian sand stones oc cur ring in the lower parts of the pro - files were formed in the ini tial stage of erg for ma tion (Kiersnowski, 1997). These sand stones are char ac ter ized by
lower min eral ma tu rity of the grain frame work (quartz grains are fewer, lithoclasts and feld spar more abun dant) than the ae olian sand stones pres ent in the up per parts of the pro files, which were cre ated dur ing max i mum erg de vel op ment. Dif fer en ti a tion of grain min eral com po si tion and the de gree of sort ing re sulted in vary ing sand stone re sis tance to com pac tion. Hence, sand - stones oc cur ring deeper were more strongly com pacted than sand stones lo cated higher in the pro file, but this does not in di - cate depth of burial.
Flu vial sand stones can also be ana lysed. The lower parts of the flu vial sand stone pro files are as so ci ated with the source ar - eas. These sand stones are char ac ter ized by high ma trix con - tent in the pore space and poor grain sort ing. How ever, in the up per part of the pro file, flu vial sand stones of ten formed in al ter - na tion with ae olian sand stones (flu vial redeposition of ae olian sands). There fore, the ma trix con tent is lower and in creases the de gree of grain sort ing, and the flu vial sand stones in the up per part of the pro file are char ac ter ized by a higher re sis tance to com pac tion than those lo cated be low.
Dif fer en ti a tion of com pac tion in ten sity prob a bly took place in the early stages of burial. Max i mum burial of Rotliegend in the Zielona Góra Ba sin was ap prox i mately 3 km (Karnkowski, 1999). The larg est sub si dence took place in the Late Perm ian and Early Tri as sic (Karnkowski, 1999; Lamarche and Scheck- Wenderoth, 2005), when Rotliegend sand stones were rap idly bur ied to ap prox i mately 2 km depth. This step could have led to a dif fer ent char ac ter of com pac tion in the sand stone pro files, which de pended on sand stone li thol ogy, but also on the con tent of early diagenetic ce ments. There fore, Weisslieg end sand - stones with sul phate and car bon ate ce ments are char ac ter ized by much lower com pac tion in ten sity than other sand stones.
Fig. 10. Map show ing the dis tri bu tion of the mean value of the RQ ra tio for the top most part (50 m) of the Up per Rotliegend and Weissliegend and dis tri bu tion of synsedimentary Rotliegend faults
The Poznañ Ba sin is char ac ter ized by much greater thick - nesses of ae olian sand stones and less di ver sity of ae olian sand - stones (dom i nated by dune sand stones). There is an ob served up ward trend in the depth of burial of sed i ments to wards the north, which is clearly as so ci ated with an in crease in sand stone com pac tion in ten sity and a de te ri o ra tion of res er voir prop er ties.
How ever, it should not be ig nored that in the cen tral part of the Rotliegend Ba sin, ae olian sed i men ta tion had a dif fer ent char ac - ter than near Wolsztyn Ridge. This dif fer ence could lead to dif fer - ing sand stone pe trol ogy and lower com pac tion re sis tance. How - ever, this prob lem has not been pre vi ously stud ied.
CONCLUSIONS
Gas res er voirs in the Zielona Góra Ba sin are lo cated within a wide area dom i nated by ae olian sand stones, which to the west pass into an area dom i nated by flu vial sand stones. Anal y - sis of the vari abil ity of res er voir prop er ties with re gard to sed i - men tary con di tions and mi cro scopic ob ser va tions made it pos - si ble to state that ce men ta tion was the most im por tant pro cess in flu enc ing the res er voir prop er ties of sand stones. The vary ing com pac tion in ten sity in sand stones was found to be more strongly re lated with sand stone li thol ogy and the pres ence of early diagenetic ce ments in sand stones than the depth of sand - stone oc cur rence.
Ce men ta tion took place in sev eral stages, of which the most im por tant was early diagenetic ce men ta tion by car bon ate and sul phate min er als, which were formed due to in fil tra tion dur ing the Zechstein trans gres sion. In fil tra tion by Zechstein ma rine wa ters caused par tial or com plete re stric tion of the nat u rally good po ros ity and per me abil ity of the sand stones un der study.
Later stages of diagenesis were prob a bly linked with se lec tive or mul ti stage ce men ta tion of mesh work illite, which caused the patchy dis tri bu tion of the cur rently ob served res er voir qual ity of the rocks. It should be pointed out that illite ce men ta tion did not cause ex treme re duc tions of po ros ity and per me abil ity, but only re duced their val ues. In ter pre ta tion of the dis tri bu tion of the RQ ra tio (po ros ity and per me abil ity ra tio) made it pos si ble to dis tin - guish ar eas with best and worst res er voir qual ity in the top most 50 m of the Zielona Góra Ba sin, which in turn en abled des ig na - tion of po ten tial pros pect ing ar eas and may serve to in ter pret the vari abil ity of res er voir prop er ties within pres ently ex ploited res er voirs. Parts of the gas res er voirs in the Zielona Góra Ba sin lie within two or even three res er voir classes (Fig. 10), as ev i - denced by the com plex diagenetic pro cesses in the sand - stones. This in di cates that gas also oc curs in rocks with poor res er voir prop er ties. This is an im por tant clue for fu ture re - search, not only in the Zielona Góra Ba sin, but also in the whole Pol ish Rotliegend Ba sin.
One ad van tage of the RQ ra tio is that it does not re quire anal y sis of two in de pend ent maps of po ros ity and per me abil ity.
The RQ ra tio is not re stricted to the search for con ven tional hy - dro car bons. It may also be help ful in de ter min ing the pres ence of tight rocks, iden ti fy ing mi gra tion routes for gases and flu ids, or search ing for res er voir rocks as geo ther mal wa ter sources and for un der ground stor age of CO2.
Ac knowl edg ments. This re search was sup ported by the In sti tute of Geo chem is try, Min er al ogy, and Pe trol ogy, War saw Uni ver sity (grant IGMiP-36-2013). The au thor would like to thank the re view ers: I. Moeck, R. Gaupp and H. Kiersnowski for their de tailed and con struc tive re marks and valu able com -
204 Anna Poszytek
Fig. 11. Dis tri bu tion of the RQ ra tio with re gard to per cent age con tent of flu vial, ae olian and shal low-ma rine de pos its in the sec tions for the top most part (50 m) of the Up per Rotliegend and Weissliegend
Fig. 12. Dis tri bu tion of the RQ ra tio with re gard to the type of the pore space fill ing in sand stones
Other ex pla na tions as in Fig ure 11
ments, which have sig nif i cantly im proved the pa per. I also thank P.H. Karnkowski, A. Maliszewska, P. Roniewicz and P. Such for the abil ity to dis cuss my re sults dur ing my Ph.D.
stud ies and T. Peryt for his re marks on the ar ti cle. Polskie Górnictwo Naftowe i Gazownictwo S.A. has kindly pro vided geo log i cal in for ma tion and Z. Miko³ajewski and A. Buniak from
the Zielona Góra Branch of the Polskie Górnictwo Naftowe i Gazownictwo S.A. have helped in the im ple men ta tion of the re - search.
REFERENCES
Amthor J.E., Okkerman J. (1998) In flu ence of early diagenesis on res er voir qual ity of Rotliegende sand stones, North ern Neth er - lands. AAPG Bul le tin, 82: 2246–2265.
Ba³a M., Jarzyna J. (2004) Zale¿noœæ miêdzy porowatoœci¹ i przepuszczalnoœci¹ w ska³ach zbiornikowych z uwzglêdnie - niem wspó³czynnika charakteryzuj¹cego przestrzeñ porow¹ (in Pol ish). Prace Instytutu Nafty i Gazu, 150: 275–279.
Beard D.C., Weyl P.K. (1973) In flu ence of tex ture on po ros ity and per me abil ity of un con sol i dated sand. AAPG Bul le tin, 57:
349–369.
BjÝrlykke K., Ramm M., Saigal G.C. (1989) Sand stone diagenesis and po ros ity mod i fi ca tion dur ing ba sin evo lu tion. Geologische Rundschau, 78: 243–268.
Buniak A. (1999) Œrodowiska depozycji i rozwój sedymentacji górnego czerwonego sp¹gowca w pó³nocnej czêœci monokliny przedsudeckiej (rejon Poznañ-Pniewy) (in Pol ish). Przegl¹d Geologiczny, 47: 465.
Buniak A., Miko³ajewski Z., Protas A. (1999) Depositional en vi - ron ment and pe trol ogy of Rotliegend de pos its from the Unis³aw-Wa³dowo Królewskie re gion (in Pol ish with Eng lish sum mary). Geologos, 4: 5–27.
Buniak A., Kuberska M., Kiersnowski H. (2009) Pet ro graph i - cal-petrophysical char ac ter is tics of the Rotliegend eolian sand - stones of the Siekierki-Winna Góra Zone (the Poznañ re gion) in the as pect of search for gas trapped in de pos its (in Pol ish with Eng lish sum mary). Przegl¹d Geologiczny, 57: 328–334.
Cade C.A., Ev ans I.J., Bryant L. (1994) Anal y sis of per me abil ity con trols: a new ap proach. Clay Min er als, 29: 491–501.
Corbett P.W.M., Pot ter G.K. (2004) Petrotyping: a basemap and at - las for nav i gat ing through per me abil ity and po ros ity data for res - er voir com par i son and per me abil ity pre dic tion. In ter na tional Sym po sium of the So ci ety of Core An a lysts, 5–9 Oc to ber, 2004, Abu Dhabi, UAE: 385–395.
Doornenbal J.C., Stevenson A.G., eds. (2010) Pe tro leum Geo log - i cal At las of the South ern Perm ian Ba sin Area. EAGE Pub li ca - tions b.v. (Houten).
Ethier V.G., King H.R. (1991) Res er voir qual ity eval u a tion from vi - sual at trib utes on rock sur faces: meth ods of es ti ma tion and clas si fi ca tion from drill cut tings or cores. Bul le tin of Ca na dian Pe tro leum Ge ol ogy, 39: 233–251.
Ev ans J., Cade C., Bryant S. (1997) A geo log i cal ap proach to permeabilty pre dic tion in clastic res er voirs. AAPG Mem oir, 69:
91–101.
Gaupp R. (1997) Diagenesis types and their ap pli ca tion in diagenesis map ping. Zentralblatt für Geologie und Paläontologie,Teil I (11/12): 1183–1199.
Gaupp R., Okkerman J.A. (2011) Diagenesis and res er voir qual ity of Rotliegend sand stones in the North ern Neth er lands. SEPM Spe cial Pub li ca tion, 98: 193–228.
Gaupp R., Matter A., Platt J., Ramseyer K., Walzebuck J. (1993) Diagenesis and fluid evo lu tion of deeply bur ied Perm ian (Rotliegende) gas res er voirs, North west Ger many. AAPG Bul le - tin, 67: 280–312.
Glen nie K. W., ed. (1990) In tro duc tion to the Pe tro leum Ge ol ogy of the North Sea, Lon don.
Glennie K.W., Buller A.T. (1983) The Perm ian Weissliegend of NW Eu rope: the par tial de for ma tion of eolian dune sands caused by the Zechstein transgresion. Sed i men tary Ge ol ogy, 35: 43–81.
Gluyas J., Leonard A. (1995) Diagenesis of the Rotliegend Sand - stone: the an swer ain’t blowin’ in the wind. Ma rine and Pe tro - leum Ge ol ogy, 12: 491–497.
Gregosiewicz Z., Protas A. (1997) Facje, diageneza a w³asnoœci zbiornikowe piaskowców czerwonego sp¹gowca rejonu z³o¿a Radlin (in Pol ish). Nafta-Gaz, 57: 375–387.
Hogg A.J.C., Mitch ell A.W., Young S. (1996) Pre dic tion of po ros ity in com pacted sands. AAPG Mem oir, 69: 1–15.
Houseknecht D.W. (1987) As sess ing the rel a tive im por tance of com pac tion pro cesses and ce men ta tion to re duc tion of po ros ity in sand stones. AAPG Bul le tin, 71: 633–642.
Jarzyna J., Puskarczyk E., Ba³a M., Papiernik B. (2009) Vari abil ity of the Rotliegend sand stones in the Pol ish part of the South ern Perm ian Ba sin – per me abil ity and po ros ity re la tion ships.
Annales Societatis Geologorum Poloniae, 79: 13–26
Jerzykiewicz T., Kijewski P., Mroczkowski J., Teisseyre A.K.
(1976) Or i gin of the Weissliegendes de pos its in the Fore-Sudetic Monocline (in Pol ish with Eng lish sum mary).
Geologia Sudetica, 11: 57–330.
Karnkowski P. (1999) Oil and Gas De pos its in Po land.
Geosynoptics So ci ety, Kraków.
Karnkowski P.H. (1986) The na ture of Zechstein trans gres sion ver - sus or i gin of Weissliegendes in the Wielkopolska area (north ern Fore-Sudetic Monocline, west ern Po land (in Pol ish with Eng lish sum mary). Geologia Sudetica, 21: 101–122.
Karnkowski P.H. (1987) Fa cies anal y sis of Wielkopolska sub group (Up per Rotliegend) in the north ern part of the Fore-Sudetic (in Pol ish with Eng lish sum mary). Przegl¹d Geologiczny, 35:
187–192.
Karnkowski P.H. (1994) Rotliegend lithostratigraphy in the cen tral part of the Pol ish Perm ian Ba sin. Geo log i cal Quar terly, 38 (1):
27–42.
Karnkowski P.H. (1999) Or i gin and evo lu tion of the Pol ish Rotliegend Ba sin. Pol ish Geo log i cal In sti tute, Spe cial Pa pers, 3:
1–93.
Karnkowski P.H. (2007) Perm ian Ba sin as a main ex plo ra tion tar get in Po land (in Pol ish with Eng lish sum mary). Przegl¹d Geologiczny, 55: 1003–1015.
Kiersnowski H. (1997) Depositional de vel op ment of the Pol ish Up - per Rotliegend Ba sin and evo lu tion of its sed i ment source ar - eas. Geo log i cal Quar terly, 41 (4): 433–456.
Kiersnowski H., Buniak A. (2006) Evo lu tion of the Rotliegend ba - sin of north west ern Po land. Geo log i cal Quar terly, 50 (1):
119–137.
Kiersnowski H., Buniak A., Kuberska M., Srokowska-Okoñska A. (2010a) Tight gas ac cu mu la tions in Rotliegend sand stones of Po land (in Pol ish with Eng lish sum mary). Przegl¹d Geologiczny, 58: 335–346.
Kiersnowski H., Peryt T.M., Buniak A., Miko³ajewski Z. (2010b) From the intra-desert ridges to the ma rine car bon ate is land chain: mid dle to late Perm ian (Up per Rotliegend-Lower Zechstein) of the Wolsztyn-Pogorzela High, west Po land. Geo - log i cal Jour nal, 45: 319–335.
Kotarba M.J., Peryt T.M., Kosakowski P., Wiêc³aw D. (2006) Or - ganic geo chem is try, depositional his tory and hy dro car bon gen - er a tion mod el ling of the Up per Perm ian Kupferschiefer and Zechstein Lime stone strata in south-west Po land. Ma rine and Pe tro leum Ge ol ogy, 23: 371–386.
Kuberska M. (2004) Diagenesis of the Rotliegend rocks in the Szczecinek-Bydgoszcz area (West ern Pomerania) (in Pol ish with Eng lish sum mary). Biuletyn Pañstwowego Instytutu Geologicznego, 411: 87–168.
Kwolek K., Buniak A. (2004) Charakterystyka geologiczna i potencja³ akumulacyjny utworów górnego czerwonego sp¹gowca w rejonie Poznañ-Ostrów Wielkopolski (in Pol ish).
Konferencja Naukowo-Techniczna „Basen permski Ni¿u Polskiego – czerwony sp¹gowiec, budowa i potencja³ zasobowy”, 23 kwiatnia 2004, Pi³a.
Lamarche J., Scheck-Wenderoth M. (2005) 3D struc tural model of the Pol ish Ba sin. Tectonophysics, 397: 73–91.
Levorsen A.I. (1967) Ge ol ogy of Pe tro leum. Free man, San Fran - cisco.
Maliszewska A. (1997) Wiek K/Ar w³óknistego illitu z piaskowców czerwonego sp¹gowca Wielkopolski (in Pol ish). In: Datowanie minera³ów i ska³, IV Ogólnopolska Sesja Naukowa, Lublin: 50–55.
Maliszewska A., Kuberska M. (1996) Cementacja piaskowców czerwonego sp¹gowca a ich porowatoœæ i przepuszczalnoœæ (in Pol ish). Nafta-Gaz, 9: 365–373.
Maliszewska A., Kuberska M. (2009) Iso to pic in ves ti ga tions of diagenetic illite of Rotliegend sand stones from theWielkopolska and West ern Pomerania re gions (in Pol ish with Eng lish sum - mary). Przegl¹d Geologiczny, 57: 322–327.
Miall A.D. (1978) Lithofacies types and ver ti cal pro file mod els in braided river de pos its: a sum mary. Mem oir, 5: 597-604.
Michalik M. (1996) Zró¿nicowanie procesów krystalizacji diagenetycznych illitów w piaskowcach permu w niecce pó³nocnosudeckiej i na monoklinie przedsudeckiej (in Pol ish).
III Ogólnopolska Sesja Naukowa „Datowanie minera³ów i ska³ w oparciu o rozpad promieniotwórczy potasu-40”, Lublin: 45–50.
Michalik M. (2000) Evo lu tion of diagenetic flu ids in the Weissliegend sand stones from the south west ern mar gin of the Pol ish Rotliegend Ba sin. Prace Specjalne PTMiN, 17: 218–220.
Michalik M. (2001) Diagenesis of the Weissliegend sand stones in the south-west mar gin of the Pol ish Rotliegend Ba sin. Prace Mineralogiczne, 91: 3–171.
Muszyñski M., Rydzewska W. (1986) Diagenetic changes in Saxonian sed i ments of the mid dle Fore-Sudetic Monocline and their im pact on res er voir prop er ties (in Pol ish with Eng lish sum - mary). Przegl¹d Geologiczny, 34: 509–514.
Nemec W., Porêbski S.J. (1977) Weissliegendes sand stones: a tran si tion from flu vial-eolian to shal low-ma rine sed i men ta tion (Lower Perm ian of the Fore-Sudetic Monocline). 1. Sed i men tary struc tures and tex tural dif fer en ti a tion. Rocznik Polskiego Towarzystwa Geologicznego, 47: 387–418.
Nikishin A.M., Ziegler P.A., Abbott D., Bru net M.F., Cloetingh S.
(2002) Permo-Tri as sic intraplate magmatism and rift ing in Eur - asia: im pli ca tions for man tle plumes and man tle dy nam ics.
Tectonophysics, 351: 3–39.
Papiernik B., Górecki W., Pasternacki A. (2010) Pre lim i nary re - sults of 3D mod el ing of petrophysical pa ram e ters for tight gas pros pect ing in the Pol ish Rotliegend Ba sin (in Pol ish with Eng - lish sum mary). Przegl¹d Geologiczny, 58: 352–364.
Peryt D., Peryt T.M., Raczyñski P., Ch³ódek K. (2012) Foraminiferal col o ni za tion re lated to the Zechstein (Lopingian) trans gres sion in the west ern part of the Wolsztyn Palaeo-Ridge area, West ern Po land. Geo log i cal Quar terly, 56 (3): 529–546.
Pettijohn F.J., Pot ter P.E., Siever R. (1972) Sand and Sand stones.
Springer-Verlag, New York.
Pokorski J., Kiersnowski H. (1999) Wybrane elementy ewolucji basenu czerwonego sp¹gowca na podstawie analizy tekto - nicznej i litofacjalnej (in Pol ish). Przegl¹d Geologiczny, 47: 464.
Poprawa P., Kiersnowski H. (2008) Po ten tial for shale gas and tight gas ex plo ra tion in Po land (in Pol ish with Eng lish sum mary).
Biuletyn Pañstwowego Instytutu Geologicznego, 429: 145–152.
Poprawa P., Kiersnowski H. (2010) Tight gas ac cu mu la tions in Rotliegend sand stones of Po land (in Pol ish with Eng lish sum - mary). Biuletyn Pañstwowego Instytutu Geologicznego, 439:
173–180.
Poszytek A. (2006) Zmiennoœæ w³aœciwoœci zbiornikowych górnego czerwonego sp¹gowca w centralnej czêœci monokliny przedsudeckiej (in Pol ish). Nafta-Gaz. 62: 559–564.
Rochewicz A. (1980) Wp³yw procesów illityzacji i chlorytyzacji na w³asnoœci kolektorskie piaskowców czerwonego sp¹gowca SW Polski (in Pol ish). Archiwum Mineralogiczne, 36: 55–61.
Such P. (1996) Model fizyczny przestrzeni filtracji basenu czerwonego sp¹gowca (in Pol ish). Prace Instytutu Nafty i Gazu, 88.
Such P., Maliszewska A., Leœniak G. (2000) W³aœciwoœci filtracyjne utworów czerwonego sp¹gowca a jego wykszta³cenie facjalne (in Pol ish). Prace Instytutu Nafty i Gazu, 103: 5–49.
Such P., Leœniak G., S³ota M. (2010) Quan ti ta tive po ros ity and per - me abil ity char ac ter iza tion of po ten tial Rotliegend tight gas res - er voirs (in Pol ish with Eng lish sum mary). Przegl¹d Geologiczny, 58: 347–351.
Sweet M.L. (1999) In ter ac tion be tween ae olian, flu vial and playa en vi ron ments in the Perm ian Up per Rotliegend Group, UK south ern North Sea. Sedimentology, 46: 171–187.
Szwarc R., Kiersnowski H. (1999) Rozwój sedymentacji osadów czerwonego sp¹gowca w SE czêœci polskiego basenu permskiego (in Pol ish). Przegl¹d Geologiczny, 47: 469–470.
Tiab D., Donaldson E.C. (2004) Petrophysics. Gulf Pub lish ing Com pany, Hous ton.
Weihe T. (1997) Sedimentologie und Fazies des Rotliegenden (unteres Perm) nördlich des Wolsztyn-Hochs, Westpolen, im Spiegel der Beckenentwicklung. Selbstverlag der Geowissen - schaftlichen In sti tute der Technische Universität, Clausthal.
Wag ner R., Peryt T.M. (1997) Pos si bil ity of se quence strati graphic sub di vi sion of the Zechstein in the Pol ish Ba sin. Geo log i cal Quar terly, 41 (4): 457–474.
Wolnowski T. (2004) Prognoza zasobnoœci czerwonego sp¹gowca w basenie permskim ni¿u polskiego w œwietle nowych technik poszukiwawczych (in Pol ish). Konferencja Naukowo- Techniczna „Basen permski Ni¿u Polskiego – czerwony sp¹gowiec, budowa i potencja³ zasobowy”, 23 kwietnia 2004, Pi³a.
Ziegler P.A. (1990) Geo log i cal At las of West ern and Cen tral Eu - rope. Shell Int. Petr. Maa.B.V.
Zwingmann H., Clauer N., Gaupp R. (1998) Tim ing of fluid flow in a sand stone res er voir of the North-Ger man Rotliegend (Perm ian) by K-Ar dat ing of re lated hy dro ther mal illite. Geo log i cal So ci ety Spe cial Pub li ca tions, 144: 91–106.
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