四川盆地龙岗东地区台缘带生物礁含气性评价  

Evaluation on gas-bearing property in platform margin bioreef,eastern Longgang area,Sichuan Basin

作　　者：韩建[1] Han Jian(Chongqing Gas District,PetroChina Southwest Oil&Gasfield Company,Chongqing 400021,China)

机构地区：[1]中国石油西南油气田公司重庆气矿

出　　处：《天然气勘探与开发》2022年第2期15-21,共7页Natural Gas Exploration and Development

摘　　要：四川盆地东部地区上二叠统长兴组生物礁是区内重要滚探目标,能较快的实现增储上产。为了解决川东地区长兴组“开江—梁平”海槽西侧台缘(下简称“海槽西侧”)生物礁及储层发育,但含气性差的问题。本次运用钻井、地震等资料,以沉积学、岩石学、油气成藏理论等为指导,分析了海槽西侧生物礁及储层发育特征,并结合构造展布特征,深入剖析了区内已完钻生物礁含气性,指出区内台缘生物礁含气性影响因素以及含气有利区,指导生物礁勘探。研究表明:①海槽西侧台缘生物礁发育,生物礁分布受相带控制,且沿台缘带断续分布,较川东其他地区生物礁规模更大;②海槽西侧台缘带生物礁储层发育,储层厚可达109.5 m,孔隙度可达6.71%,为裂缝—孔洞型储层,储层非均质性强,且随生物礁沿台缘带断续分布;③海槽西侧台缘(生物礁)与区内高陡构造带及断裂系统几乎垂直接触,构造及断裂系统,和生物礁储层非均质性共同控制生物礁含气性。结论认为,研究成果指出了区内生物礁含气性因素及有利区,有助于川东地区老气田稳产,对四川盆地生物礁勘探开发具有重要的指导意义。In eastern Sichuan Basin,the bioreef of Upper Permian Changxing Formation represents an important progressive exploration target for rapid increase of reserves and production.However,these bioreef reservoirs well developed in the platform margin on the west side of Kaijiang-Liangping trough are featured by poor gas-bearing property.So,according to sedimentology,petrology,and reservoir-forming theory,the development characteristics of the bioreef reservoirs on the west side of the trough were analyzed using drilling,seismic,and other data.Then,the gas-bearing property was investigated depending on structural distribution.And the factors affecting this property in the platform margin bioreef and favorable gas-bearing zones in the study area were analyzed.Results show that(1)the bioreef reservoirs developed in the platform margin on the west side of the trough extend under the control of facies belt and discontinuously along the platform margin,showing a larger scale than other areas in eastern basin;(2)they belong to fractured-vuggy reservoirs with the thickness of 109.5 m and the porosity of 6.71%,strong heterogeneity,and discontinuous extension along the platform margin;and(3)the platform margin on the west side of the trough(bioreef)is in almost vertical contact with the high and steep structural belts and faults in the area,and these belts and faults as well as the heterogeneity of the bioreef reservoirs jointly control the gas-bearing property.In conclusion,it is deemed the factors affecting the gas-bearing property and some favorable reef zones,which is helpful to keeping the stable production of the old gasfields in eastern basin and may guide the exploration and development of bioreef reservoirs in Sichuan Basin.

关 键 词：四川盆地 龙岗东地区 晚二叠世 长兴组 开江—梁平海槽西侧 台缘带 生物礁 含气性评价 

分 类 号：P618.13[天文地球—矿床学]