摘要
碳酸盐岩地层天然裂缝较发育,钻井时易漏失,影响钻井施工安全。漏失压力预测是防漏堵漏的关键。在孔隙型或含微裂缝的砂、泥岩地层中,依据破裂压力设计钻井液安全密度上限值是比较合理的,然而在缝洞发育的碳酸盐岩地层中,往往使得钻井液设计密度值偏大。在地应力建模和成像测井分析的基础上,利用源自斯坦福大学研究成果的Mohrfracs裂缝分析软件对麦盖提1区的碳酸盐岩地层进行了裂缝渗透性分析,模拟计算了裂缝漏失压力,并与该区钻井实际进行了对比,最终结合孔隙压力、坍塌压力的研究结果,对该区碳酸盐岩地层钻井安全密度窗提出了建议。
In carbonate reservoirs,natural fractures were developed,and lost circulation was easily induced and impact on drilling safety would be caused.The prediction of lost circulation pressure was the key of leak resistance and sealing.It was reasonable for designing the upper limit of drilling fluid safety density in sandstone or mudstone formations with small pores or micro-cracks,a higher safe density value of drilling fluids was often designed.Carbonate reservoir developed fractures or caverns.This paper analyzed the fracture permeability and computed lost circulation pressure for Maikit Block1 by using Mohrfracs software on the base of earth stress model and FMI imaging logging data.Analysis results are used for comparing it with drilling information.After pore pressure and collapse pressure are taken into consideration,a suggestion for the safety density window of drilling fluid is put forward.
出处
《石油天然气学报》
CAS
CSCD
2012年第9期109-112,6,共4页
Journal of Oil and Gas Technology
