A COMPARATIVE STUDY OF RESERVOIRS OF THE CHANGXING AND FEIXIANGUAN FORMATION BETWEEN PUGUANG GASFIELD AND JIANNAN GASFIELD IN THE SICHUAN BASIN
-
摘要: 普光气田和建南气田位于四川盆地东北部,两气田的主力产层二叠系长兴组、三叠系飞仙关组均为礁滩沉积,但储层规模、储集性却差异很大。普光气田储层厚度大、物性好,以中孔中渗、高孔高渗的大套溶孔白云岩为主,而建南气田储层厚度小、物性差,以低孔低渗为主,岩性为灰岩和少量白云岩。研究认为,白云岩成因的差异造成了2个气田储层的差异。普光气田以准同生白云岩化为主,形成了大量早期白云岩;建南气田以埋藏白云岩化为主,形成的白云岩数量少。白云岩成因的差异与沉积环境密切相关,普光气田礁滩沉积毗邻局限台地或蒸发台地,容易获得高Mg/Ca比咸水,有利于准同生白云岩化发育;而建南气田礁滩沉积毗邻开阔台地,不利于准同生白云岩化的发育。因此,毗邻蒸发台地或局限台地等环境的礁滩相更有利于优质储层的发育。Abstract: Puguang Gasfield and Jiannan Gasfield are located in Northeast Sichuan Basin.As the main gas bearing zones,the Permian Changxing and Triassic Feixianguan Formations are all reef-bank deposits.However,the reservoir scale and property are greatly different between Puguang Gasfield and Jiannan Gasfield.The reservoirs in Puguang Gasfield are mainly a large set of dolomites with the characteristics of dissolution pores,great thickness,medium porosity and medium permeability,high porosity and high permeability.However,the reservoirs in Jiannan Gasfield are mainly limestones and a little dolomites with the characteristics of thin thickness,low porosity and low permeability.Based on the comparative study on the formation conditions,the primary factor for differences towards the reservoirs between Puguang Gasfield and Jiannan Gasfield is the origin of the dolomites.The former well developed penecontemporaneous dolomitization and formed a large set of dolomites while the latter developed burial dolomitization and formed a little dolomites.Correlation analysis results showed that there is a close correlation to the differences of the sedimentary environment.The reef-bank facies are adjacent to the restricted platform facies or evaporate platform facies in Puguang Gasfield,however,which are adjacent to the open platform facies in Jiannan Gasfield.As a result,the former is easier to acquire saline water of high Mg/Ca values and beneficial to penecontemporaneous dolomitization while the latter is not avail to penecontemporaneous dolomitization.Consequently,it is suggested that the reef-bank facies adjacent to the sedimentary environment such as restricted platform facies or evaporate platform facies are advantageous to forming quality reservoirs.
-
[1] 马永生,傅强,郭彤楼,等.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):455-460. [2] 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. [3] 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. [4] 马永生,郭旭升,郭彤楼,等.四川盆地普光大型气田的发现与勘探启示[J].地质论评,2005,51(4):477-480. [5] 王恕一,蒋小琼,管宏林,等.川东北地区普光气田飞仙关组储层孔隙演化[J].石油实验地质,2009,31(1):26-30. [6] 王恕一,蒋小琼,管宏林,等.川东北普光气田鲕粒白云岩储层粒内溶孔的成因[J].沉积学报,2010,28(1):10-16. [7] 李振宏,杨永恒.白云岩成因研究现状及进展[J].油气地质与采收率,2005,12(2):5-8. [8] VEIZER J,HOEDS J.The nature of O18/O16 and C13/C12 secular trends in sedimentary carbonate rocks[J].Geochim Cosmochim Acta,1976,40(11):1387-1395. [9] 詹姆斯 N P,肖凯 P W.古岩溶[M].张绍海译.北京:石油工业出版社,1992. -
计量
- 文章访问数: 1331
- HTML全文浏览量: 53
- PDF下载量: 1003
- 被引次数: 0