塔河侧钻水平井硬脆性泥页岩井壁失稳研究及对策  

RESEARCH AND COUNTERMEASURES OF HARD BRITTLE SHALE BOREHOLE INSTABILITY IN TAHE SIDETRACKING HORIZONTAL WELL

作　　者：张国[1] 陈红壮[1] 高伟[1] 侯子旭 刘贵传[1] 

机构地区：[1]中石化石油工程技术研究院 [2]中石化西北油田分公司

出　　处：《钻采工艺》2016年第3期4-7,127,共4页Drilling & Production Technology

基　　金：中石化科技开发部重点项目"塔河托甫台区块深井开窗侧钻钻完井技术研究";项目编号:P09004

摘　　要：考虑到避水与垂深的限制,将塔河侧钻水平井的造斜点设置在石炭系巴楚组或桑塔木组。此外,造斜段在泥岩段钻进井段较长,钻井液的浸泡作用使井壁极易掉块坍塌,卡钻等复杂情况经常发生。通过黏土矿物、理化特性、CT扫描等手段分析了易失稳泥岩的组构特征,易失稳地层属硬脆性泥岩,微裂隙发育。高温高压浸泡岩心,进行CT扫描观察微裂隙扩展,并测试其抗压强度评价钻井液的抑制封堵性。采用多元协同的钻井液防塌机理,兼顾物理化学封堵、抑制泥页岩表面水化、井壁固结以及合理的钻井液密度,开发了可以有效应对硬脆性泥页岩剥落掉块的强抑制强封堵钻井液。经过TK227CH井的现场试验,取得良好的应用效果,垮塌掉块明显减少,井径规则,保证了侧钻水平井在复杂泥岩段的安全施工。Considering the water avoidance and vertical depth limit,the deflection point of the Tahe sidetracking horizontal well was set in C_1b and O_3s Formation. In addition,for the building up section was longer in mudstone,the side wall was easily collapsing and breaking under the drilling fluid soaking condition,and the sticking often happens. The fabric characteristics of instability mudstone were analyzed by clay mineral content,physicochemical properties and CT scanning etc.,it belongs hard brittle shale,and the microfracture was developed.And the spread of microfracture was observed by core CT scan after core was soaked under high temperature and high pressure,and its compression strength was tested to evaluate the sealing characteristics and inhibitive ability of drilling fluid. Based on the multiple anti-sloughing mechanism of drilling fluid,both physical and chemical plugging,inhibition of shale hydration,wall surface consolidation and reasonable drilling fluid density,the drilling fluid with strong inhibition and plugging was developed,which could effectively deal with the hard brittle shale peeling. Through field application in TK227CH well,good effect was obtained,sidewall collapsing and breaking were significantly reduced,the drilling safety of sidetracking horizontal well was ensured in complex mudstone section.

关 键 词：侧钻水平井 硬脆性泥岩 CT扫描 多元协同 强抑制 强封堵 

分 类 号：TE21[石油与天然气工程—油气井工程]