碳质泥岩钻水平井防塌工艺措施  

Discussion on Anti-collapse Technical Measures of Drilling Horizontal Wells in Carbonaceous Mudstone

作　　者：王勇强[1,2] 陈恩让 曹辉[1,2] WANG Yongqiang;CHEN Enrang;CAO Hui(Drilling and Production Engineering Research Institute,Chuanqing Drilling Engineering Co.,Ltd.,Xi’an,Shaanxi 710018,China;National Engineering Laboratory for Exploration and Development of Low Permeability Oil&Gas Fields,Xi’an,Shaanxi 710018,China)

机构地区：[1]中石油川庆钻探工程有限公司钻采工程技术研究院,710018 [2]低渗透油气田勘探开发国家工程实验室

出　　处：《钻采工艺》2021年第1期138-141,共4页Drilling & Production Technology

基　　金：中国石油天然气集团公司川庆钻探工程有限公司科研项目“长庆气田水平井碳质泥岩井壁稳定钻井液技术研究”(编号:CQ2016B-11-1-3)。

摘　　要：陕北气田气井水平井钻井过程中,随着水平段长度的延伸(水平段长度大于1 500 m)和地层的不均质性,钻遇泥岩特别是碳质泥岩的概率较高。在水平段和大斜度井段钻遇大段碳质泥岩后,造成井壁失稳井下复杂频发,侧钻率较高,特别是上古生界山西组碳质泥岩,质地坚硬,微裂缝、微裂纹发育,易造成较大较多的碳质泥岩掉块,活动钻具不易破碎,掉块携带难度大,井眼清洁困难,易造成起下钻过程中,钻具遇阻、遇卡,甚至起钻过程中在套管内卡钻,造成井下事故。而在直井钻进过程中,山西组碳质泥岩井段一般很少出现井壁稳定问题。因此水平段钻遇大段碳质泥岩后,从目前来看,仅从严格控制钻井液性能来解决这一问题还有一定难度,如果在强化封堵性、抑制性等钻井液性能的基础上,配合精细合理的工程措施,可明显降低碳质泥岩井段的遇阻遇卡程度,对钻穿水平段大段碳质泥岩、稳定井壁、井眼清洁、保障钻井施工井下安全会起到积极的作用。During the drilling of a horizontal gas well in the North Shaanxi Gas Field,with the extension of the horizontal section length(the length of the horizontal section is greater than 1500m)and the heterogeneity of the formation,the probability of encountering mudstone,especially carbonaceous mudstone is higher during the drilling process.After drilling into large sections of carbonaceous mudstone in the horizontal section and highly deviated well section,the borehole lining instability occurs frequently resulting in high sidetracking rate,especially in the carbonaceous mudstone of Shanxi Formation of the Upper Paleozoic,with hard texture and micro-cracks and micro-fractures are developed,which can easily cause larger and more carbonaceous mudstone to fall off,which is difficult to be broken with the movable drilling tool,and difficult to be carried out and the wellbore is hard to be clean.It is easy to cause the drilling tool to get stuck in the process of tripping,or even to get stuck in the casing in the process of tripping,resulting in downhole accidents.In the process of vertical well drilling,in the carbonaceous mudstone section of the Shanxi Formation,the borehole stability problem is generally rare.Therefore,after the horizontal section is drilled into a large section of carbonaceous mudstone,it is still difficult to solve this problem only by strictly controlling the performance of the drilling fluid.If the performance of the drilling fluid is strengthened on the basis of sealing and inhibiting properties,with careful and reasonable engineering measures,it can significantly reduce the degree of resistance and jamming of carbonaceous mudstone well sections,and will play a positive role in drilling through large sections of carbonaceous mudstone in horizontal sections,stabilizing the borehole,cleaning the wellbore,and ensuring downhole safety in drilling operations.

关 键 词：碳质泥岩 水平井 套管内卡钻 遇阻 微裂缝发育 硬脆性泥岩 

分 类 号：TE28[石油与天然气工程—油气井工程]