缝洞型碳酸盐岩定容油藏形成机理及开发技术

Forming Mechanism and Development Measures of Constant-Volume Fractured-Vuggy Carbonate Oil Reservoirs

碳酸盐岩定容油藏多分布在分支断裂周围,储集层类型以洞穴型为主,具地层能量弱、地层压力下降快、单井控制范围小、无地层水产出等特征。综合分析认为,油气成藏后,伴随着构造运动及油气充注的停止,分支断裂油藏油水界面之下的地层水处于相对静止状态,方解石从地层水中析出,堵塞了油水界面下的早期流体运移通道,油水界面以上油气被封闭,形成无水的定容油藏。基于定容油藏的动静态特征及开发实践,提出了一井多靶点注水替油开发技术。

Constant?volume carbonate reservoirs are mostly distributed around branch faults and dominated by cavernous reservoirs which are characterized by weak formation energy,rapid drop of formation pressure,small controlling range of single well and no yield of forma?tion water.The comprehensive analysis shows that with the stop of tectonic movement and hydrocarbon charging,the formation water under the water?oil contact in the branch faults was in a relative static state after hydrocarbon accumulation,calcite separated from the formation water and plugged the early fluid migration paths under the water?oil contact,oil and gas sealed the spaces above the water?oil contact and finally constant?volume reservoirs with no water formed.Based on the study of the dynamic and static characteristics of constant?volume res?ervoirs and reservoir development practices,the paper presents 2 development measures such as multiple targets in one well and water?in?jection oil production.