摘要
近年来,柴达木盆地英西地区下干柴沟组上段(E_3~2)低孔超低渗油气藏勘探连续取得突破,勘探证实区内裂缝系统与油气富集高产存在联系,因此明确其裂缝成因机制,具有重要的油气地质意义。以岩石学特征、物性、自源超压与裂缝的匹配关系为基础,结合不同成因机制的裂缝与油气产能的关系,同时综合构造、盐岩以及岩石物理实验,提出英西地区异常高压油气藏的预测方法。研究结果表明:(1)多期复杂构造运动形成了大量构造缝,但多被硬石膏充填;(2)下部相对优质的烃源岩在生-排烃过程中产生异常高压而破裂,并在上部稳定岩盐盖层作用下得以保存,形成大量对油气运移起输导作用的有效缝;(3)基于有效缝成因机制与模式,可通过地震属性、岩盐厚度以及异常高压分布,结合古地貌特征,准确预测英西地区油气高产富集区的分布。该研究成果对于区内致密碳酸盐岩油气勘探具有指导意义。
In recent years,a continuous breakthrough of low porosity and ultra-low permeability hydrocarbon reservoir exploration of the upper member of the Xiaganchaigou Formation(E3 2)in Yingxi area of Qaidam Basin has been made.The exploration works identified that enrichment and high yield of oil&gas were related to the fracture system in this area.Therefore,it is of great geological significance to clarify the fracture genesis mechanism.Based on the matching relationship among petrological characteristics,physical properties,self-source overpressure and fractures,and combined with the relationship between different fractures and oil&gas yield,tectonic and salt rock simulation experiment,rock physics experiment,the prediction method of abnormal high pressure reservoir in Yingxi area was proposed.The results show that:(1)The complex multi-period tectonic movement formed a large number of structural fractures,but most of them were filled with anhydrite.(2)Good hydrocarbon source rocks buried in deeper part of this stratum were fractured by overpressure that formed during the hydrocarbon generation and expulsion processes.At the same time,the overpressure and fractures were preserved by stable salt seal layer developed in the upper part of the stratum,leading to form a giant number of effective fractures that acted as oil&gas migration pathways.(3)Based on the genesis mechanism and model of effective fracture,seismic attributes,salt rock thickness,overpressure distribution law and palaeogeomorphologic features,the distribution of oil&gas enrichment and high yield areas could be predicted accurately.This study acted an important guiding significance for the oil and gas exploration of tight carbonate reservoirs in this area.
作者
李翔
王建功
张平
李琳
黄成刚
伍坤宇
张庆辉
龙伟
LI Xiang;WANG Jiangong;ZHANG Ping;LI Lin;HUANG Chenggang;WU Kunyu;ZHANG Qinghui;LONG Wei(PetroChina Research Institute of Petroleum Exploration and Development-Northwest,Lanzhou 730020,China;Key Laboratory of Reservoir Description,CNPC,Lanzhou 730020,China;Research Institute of Exploration and Development,PetroChina Qinghai Oilfield Company,Dunhuang 736200,Gansu,China)
出处
《岩性油气藏》
CSCD
北大核心
2018年第6期45-54,共10页
Lithologic Reservoirs
基金
国家重大科技专项"柴达木盆地复杂构造区油气成藏
关键勘探技术与新领域目标优选"(编号:2016ZX05003G006)
中国石油股份有限公司重大科技专项"柴达木盆地建设高原大油气田勘探开发关键技术研究与应用"(编号:2011E-05)联合资助
关键词
异常高压
水力破裂缝
三轴应力实验
叠后振幅方位分解
下干柴沟组
柴达木盆地
abnormal high pressure
hydraulic fracture
triaxial stress test
poststack amplitude azimuth decomposition
Xiaganchaigou Formation
Qaidam Basin
