摘要
大牛地气田马家沟组顶部风化壳之下更深层位存在明显的岩溶作用,是深部致密碳酸盐岩形成储集空间的关键。针对马家沟组中下组合岩溶发育机理不明确的问题,综合利用岩心、薄片、测井和地球化学等资料,结合区域构造和沉积背景,从岩溶相角度开展了中下组合岩溶发育机制研究。主要取得以下认识:①提出了具有成因意义的四类岩溶相(破裂相、垮塌相、搬运相和膏溶针孔相)划分方案,并明确了各岩溶相所指示岩溶作用的类型、强度和形成条件;②中下组合发育表生期岩溶和同生期岩溶,表生期岩溶表现为侧向和垂向岩溶水叠加改造,在马五6-10亚段均有发育,以马五6亚段最为强烈,主要形成膏溶孔、溶洞和裂缝;同生期岩溶发育于马五7亚段、马五9亚段和马三段、马二段,以相对海退期大气淡水弱改造为主,主要发育晶间孔和晶间溶孔;③依据岩溶作用影响因素建立了“浅层侧向补给+断裂沟通+易溶岩相+水平扩展”的立体岩溶模式,为马家沟组中下组合岩溶储层评价和预测提供了依据。
In Daniudi gas field,there exists obvious karstification under the weathering crust at the top of Majiagou formation,which is the key to the formation of deep tight carbonate reservoir space.At present,the karst development mechanism of the middle and lower Majiagou formation is not clear.Based on the core,thin section,well logging and geochemical data,combined with regional tectonic and sedimentary background,the development mechanism in middle-lower Majiagou formation is analyzed from the perspective of karst facies.The main conclusions are as follows:①The division scheme of four types of karst facies(fracture facies,collapse facies,transport facies and gypsum solution pinhole facies)with genetic significance is put forward,and the type,intensity and formation conditions of karstification indicated by each karst facies are classified.②The middle-lower Majiagou formation developed supergene and contemporaneous karstification,the supergene karstification was characterized by lateral and vertical karst water superimposed transformation,which was mainly developed in Ma56-10 sub-members,especially in M56 sub-members,and mainly formed gypsumdissolved holes,karst caves and fissures.The contemporaneous karst was developed in Ma57&Ma59sub-membersand Ma4&Ma2 members,dominated byweak transformation of atmospheric fresh water during relative regression period.Besides,intergranular pores and intergranular dissolved pores are mainly developed.③According to the influencing factors of karstification,a three-dimensional karst model of"shallow lateral recharge+faulting communication+soluble karst facies+horizontal expansion"is established,which provides a basis for the evaluation and prediction of karst reservoirs in the middle lower combination of Majiagou formation.
作者
何云
雷涛
胥旺
邓虎成
唐明远
崔璐
HE Yun;LEI Tao;XU Wang;DENG Hucheng;TANG Mingyuan;CUI Lu(Huabei Oil&Gas Company,SINOPEC,Zhengzhou,Henan 450006,China;College of Energy Resources,Chengdu University of Technology,Chengdu,Sichuan 610059,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploration,Chengdu University of Technology,Chengdu,Sichuan 610059,China)
出处
《石油地质与工程》
CAS
2022年第4期26-33,共8页
Petroleum Geology and Engineering
关键词
大牛地气田
马家沟组
表生岩溶
同生岩溶
岩溶模式
Daniudi gas field
Majiagou formation
supergene karst
syngenetic karst
karst model
