PORE EVOLUTION OF RESERVOIRS OF FEIXIANGUAN FORMATION IN PUGUANG GASFIELD IN NORTHEASTERN SICHUAN
-
摘要: 川东北地区普光气田飞仙关组储层主要为台地边缘鲕滩沉积,岩性主要为鲕粒白云岩和结晶白云岩。成岩早期受大气淡水溶蚀,形成一些次生溶孔,但和原生孔隙一起多被早期胶结物填塞。白云化也产生少量晶间孔,一般小于1%,现今有效孔隙主要为埋藏期形成的溶蚀孔缝。埋藏溶蚀大致发育两期,Ⅰ期埋藏溶蚀发生在构造挤压之后,石油充注之前,溶蚀作用与富含有机酸和二氧化碳的酸性流体有关,形成的溶蚀孔隙约占现今储层孔隙的40%;Ⅱ期埋藏溶蚀发生在充注石油演化为沥青之后,溶蚀流体可能与TSR反应产生的酸性流体有关,形成的孔隙约占现今储层孔隙的60%。孔隙演化表明,对普光气田优质储层贡献最大的成岩作用是白云化作用、构造挤压作用和早、晚两期埋藏溶蚀作用。Abstract: The reservoirs of Feixiangaun Formation in Puguang gasfield in northeastern Sichuan are mainly consisted of sediments of platform marginal ooilite beach,with principle rocks of ooilite dolomite and crystalline dolomite.Due to fresh water dissolution in the early stage of diagenesis,some secondary solutional voids were developed.However,these voids and the primary pore were largely filled by early cement.Small amount,normally less than 1%,of intercrystalline pore was formed as a result of dolomitization.Present effective pores mainly are solutional voids and fractures formed during the burial period.There were two stages of burial dissolution,with stage Ⅰ was developed after structural compression but before oil filling.Dissolution was related to acid flow with rich organic acid and carbon dioxide.The pores formed in this period accounted for 40% of present porosity of reservoirs.Stage Ⅱ dissolution was developed after the filled oil was transferred to bitumen.The acid flow might be related to the pro-ducts of themochemical sulfate reduction(TSR).Its porosity accounted for 60% of present reservoirs.In terms of pore evolution,the favorable diagenesis for formation of good reservoirs included dolomitization,structural compression and early and late burial dissolution.
-
Key words:
- pore evolution /
- reservoir Lower /
- Triassic /
- Feixianguan Formation /
- Puguang gasfield /
- northeastern Sichuan
-
[1] 马永生,蔡勋育,李国雄.四川盆地普光大型气藏基本特征及成藏富集规律[J].地质学报,2005,79(6):858~865 [2] 马永生.中国海相油气田勘探实例之六——四川普光大气田的发现与勘探[J].海相油气地质,2006,(2):35~40 [3] 马永生,傅强,郭彤楼.川东北地区普光气田长兴-飞仙关气藏成藏模式与成藏过程[J].石油实验地质,2005,27(5):455~461 [4] 蔡立国,饶丹,潘文蕾等.川东北地区普光气田成藏模式研究[J].石油实验地质,2005,27(5):462~467 [5] 蔡勋育,马永生,李国雄等.普光气田下三叠统飞仙关组储层特征[J].石油天然气学报,2005,27(1):43~45 [6] 王一刚,刘划一,文应初等.川东北飞仙关组鲕滩储层分布规律勘探方法与远景预测[J].天然气工业,2002,22(增刊):14~19 [7] 徐世琦,洪海涛,张光荣等.四川盆地下三叠统飞仙关组鲕粒储层发育的主要控制因素分析[J].天然气勘探与开发,2004,27(1):1~3 [8] 曾德铭,王兴志,王思仪.溶蚀在川东北飞仙关组储层演化中的意义[J].西南石油学院学报,2007,29(1):15~18 [9] 何莹,郭旭升,张克银等.川东北飞仙关组优质储层形成研究[J].天然气工业,2007,27(1):12~16 [10] Sun S Qing.Dolomite Reservoirs:Porosity Evolution and Reservoir Characteristics[J].AAPG Bulletin,1995,79(2):186~204 -
计量
- 文章访问数: 1390
- HTML全文浏览量: 51
- PDF下载量: 1004
- 被引次数: 0