碳酸盐岩储集层钻井井涌特征及井涌风险评价

发布时间：2018-07-31 11:26

【摘要】：以塔中顺南地区碳酸盐岩储集层为例,分析碳酸盐岩储集层钻井井涌特征,建立井涌风险定量评价方法,并进行算例分析。依据钻井地质资料,分析塔中顺南地区碳酸盐岩储集空间特点与气体侵入井筒机制,发现储集层裂缝及孔洞发育,气体主要以压差与气液置换方式侵入井筒。综合考虑气体侵入井筒机制、气体在井筒中运移规律和井筒温度-压力场,并引入井筒气相体积分数密度函数,建立了井涌风险定量评价方法和井控风险分级方法。算例分析结果表明:可采用施加井口回压法判定井底气体侵入方式;碳酸盐岩储集层孔缝洞发育特征和酸性气体对井筒气相体积分数影响较大,易引发难监测、高强度井涌;井深、井径、钻井液密度、钻井液排量、钻井液黏度和钻速对井涌风险的影响依次减弱。
[Abstract]:Taking carbonate reservoir in Shunan area of Tazhong as an example, the characteristics of well bore in carbonate reservoir are analyzed, and the quantitative evaluation method of well bore risk is established. Based on drilling geological data, the characteristics of carbonate reservoir space and the mechanism of gas intrusion into wellbore in Shunnan area of Tazhong are analyzed. It is found that reservoir fractures and holes are developed, and gas mainly invades the wellbore by pressure difference and gas-liquid replacement. Considering the mechanism of gas intrusion into wellbore, gas migration law and wellbore temperature-pressure field in wellbore, and introducing gas phase volume fraction density function of wellbore, a quantitative evaluation method of wellbore outburst risk and a well control risk classification method are established. The result of example analysis shows that the method of applying wellhead back pressure can be used to determine the invasion mode of bottom-hole gas, the characteristics of pore fracture and cavity development in carbonate reservoir and acid gas have great influence on gas phase volume fraction of wellbore, which is easy to lead to difficult monitoring and high intensity wellbore. The effects of well depth, well diameter, drilling fluid density, drilling fluid displacement, drilling fluid viscosity and drilling speed on wellbore risk are weakened in turn.
【作者单位】：中国石油大学(华东)石油工程学院;中海油能源发展股份有限公司工程技术深圳分公司;
【基金】：国家重点基础研究发展计划(973)项目(2015CB251200) 国家科技重大专项(2016ZX05020-006) 长江学者和创新团队发展计划(IRT_14R58)
【分类号】：TE28

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