哈拉哈塘油田生产井井壁垮塌原因分析

Analysis on the causes of the open-hole section collapse of oil production wells in Halahatang Oil field

杨文明 昌伦杰 朱轶 高春海 罗慎超

YANG Wenming CHANG Lunjie ZHU Yi GAO Chunhai LUO Shenchao

中国石油塔里木油田分公司开发事业部

Development Management Department, CNPC Tarim Oil field Company, Korla 841000, Xinjiang, China

哈拉哈塘油田油井主要采用裸眼完井方式，生产过程中由于井壁失稳，部分井裸眼段发生不同程度井壁垮塌，造成油井减产或者停产。通过对垮塌井返出岩样及井径测井的综合分析，确定了井壁垮塌层位主要为良里塔格组及一间房组。从井壁垮塌机理角度，对地应力场及垮塌井的垮塌层位、完井方式、储层类型、生产特征等进行了分析，得出井壁垮塌主要由油井外因和内因综合作用引起的，内因包括储层性质、储集规模和区域地应力；外因包括完井方式和储层改造措施。认为井眼轨迹与天然裂缝的匹配关系对井壁稳定有一定的影响（内因），而地应力失衡、岩石强度低、地层压力释放以及酸压、射孔是哈拉哈塘油田井壁垮塌的外因，也是主要原因。

The oil wells in Halahatang Oilfeld are mainly in the pattern of open hole completion. Due to the borehole instability in the process of production, wellbore collapse of different degrees happen in some open-hole sections, leading to production reduction and even shut in of the oil wells. And as a result, the normal production of the oil wells is seriously impacted. In this paper, the return cuttings and the caliper log of collapsed wells were analyzed comprehensively. It is fgured out that the wellbore collapse mainly occurs in the Lianglitage Formation and Yijianfang Formation. Then, the in-situ stress feld and the collapse horizon, completion mode, reservoir type and production performance of collapsed wells were analyzed from the viewpoint of wellbore collapse mechanisms. It is indicated that the wellbore collapse is mainly caused by the joint effect of internal and external factors of oil wells. The internal factors include reservoir property, reservoir scale and regional in-situ stress, and the external factors include completion mode and reservoir stimulation measure. It is revealed that the matching relation between the well track and the natural fracture has some effect on wellbore stability(the internal factor), and in-situ stress imbalance, low rock strength, formation pressure release, acid fracturing and perforation are the external factors as well as the main causes of wellbore collapse in Halahatang Oilfeld.

10.13639/j.odpt.2017.04.006