准噶尔盆地中部区块深井安全高效钻井液技术  

Safe and Efficient Water Based Drilling Fluid Technology for Deep Well in Central Block of Junggar Basin

作　　者：杨倩云 王宝田 邱春阳 Yang Qianyun;Wang Baotian;Qiu Chunyang(Drilling Technology Research Institute of SINOPEC Shengli Oilfield Service Corporation,Dongying Shandong 257017)

机构地区：[1]中石化胜利石油工程有限公司钻井工艺研究院,山东东营257017

出　　处：《中外能源》2020年第S01期55-61,共7页Sino-Global Energy

摘　　要：准中区块地质构造复杂、储层埋藏较深,由于同一裸眼井段存在多套压力体系,地层层理、孔隙和微裂缝发育并夹杂易水化膨胀黏土矿物,且中下部地层发育硬脆性泥岩,西山窑组及八道湾组地层煤层节理微裂缝发育,层间胶结力差,容易频发大量掉块、坍塌、卡钻等井壁严重失稳事故。在分析准中区块地层失稳因素及机理的基础上,遵循"化学抑制+物理封堵+力学平衡为主"的井眼稳定原则以及"低黏土相+低塑性黏度+低亚微米粒子含量+高清洁润滑性"的提速原则,研制出适合准中区块的水基安全高效钻井液技术。该技术在准中区块现场应用10口井,中1区块和中2区块4口井全井无事故,平均机械钻速分别提高55.4%和37%;中4区块6口井,井眼扩大率显著降低,平均机械钻速提高31.3%,复杂时效降低77.07%。达到了稳定井壁,提高机械钻速的目的。The central block of Junggar Basin is characterized by complicated geological structures and deep burialdepth of reservoir.At the same open hole section,multiple pressure systems appeared,and beddings,pores and microfractures developed mixed with easily swellable clay minerals in the formations.Moreover hard and brittle mudstones developed in the middle and lower formations,and microfractures in coal seam developed in Xishanyao and Badaowan Formation with weak cementing,so dropping,collapsing,sticking andother drilling incidents easily occurred.Based on the analysis of unstability factors and mechanism,the principles of downhole stability and speed-up are proposed,and a safe and efficient waterbased drilling fluid technology suitable for the central block of Junggar Basin is developed.The downhole stability principle includes chemical inhibition,physical sealing and mechanical equilibrium.The speed-up principle includes low clay facies,low plastic viscosity,low submicron particle concentration and high cleaning lubricity.This technology has been applied in ten wells of block 1,block 2 and block 4 in central block of Junggar Basin.There are no accidents in four wells of block 1 and block 2,and average rate of penetration increased by 55.4%and 37%.In six wells of block 4,borehole enlargement ratio decreased greatly,average rate of penetration increased by 31.3%,and complex outage time decreased by 77.07%.Therefore,this technology can stabilize the downhole and increase the rate of penetration.

关 键 词：水基钻井液 硬脆性泥岩 抑制封堵 稳定井壁 提速 准中区块 

分 类 号：TE254[石油与天然气工程—油气井工程]