海水基氯化钾钻井液在仙鹤4井的应用  

Use of Sea Water Potassium Chloride Drilling Fluid in Evaluation Well Xianhe-4

作　　者：刘榆[1] 李先锋[1] 卿鹏程[1] 

机构地区：[1]辽河石油勘探局钻井一公司泥浆公司,辽宁盘锦124010

出　　处：《油田化学》2005年第2期101-103,共3页Oilfield Chemistry

摘　　要：辽河滩海仙鹤地区一些层段钻进中易发生坍塌的原因是:粘土矿物水化、膨胀、分散及运移;外来流体侵入泥页岩层理及裂缝;负压钻井引起井壁力学失稳。在超高压、强造浆、强坍塌应力、可溶盐污染的沙河街组,高密度钻井液流变性能难控制,润滑性能难保证,易发生井下复杂情况及压差粘附卡钻。基于强抑制、严封堵、适当高密度防塌和流变性、造壁性、抑制性协调统一的思路,研制了一种海水基氯化钾钻井液,报道了钻井液组成,给出了基本配方,该配方中不包含降粘剂。详细介绍了在仙鹤4井(评价井)钻进中钻井液的配制、转化及维护措施;使用该体系钻井液钻进时,起下钻、钻进顺利,返出的砂样完整,井径扩大率平均5.6%,最大缩径率2.8%,电测顺利,岩心收获率97.65%,钻井液流变性控制良好,钻井周期短(60天)。Easy collapsibility of some well sections in Xianhe beach/offshore district, Liaohe, originates from hydration, swelling, dispersion and transfer of clay minerals; incursion of foreign fluids into shale beddings and fissures; and mechanical destabilization of borehole walls at underbalanced conditions. In the course of drilling in Shahejie formation strata characterized by ultra-high pressure, high yielding, high collapsibility and soluble salts contamination, the rheologic behavior of high density fluids is very difficult to be controlled properly and their lubricity is rather bad, which leads to frequent downhole complications and differential pipe sticking. A sea water base KC1 drilling fluid is designed and developed for use in this district with two principles taken into consideration： ① antisloughing through strong inhibiting and sealing capacities and properly high fluid density; ② eoncurence of rheologic behavior, wall building and shale inhibition. The composition of the fluid is presented and its reeept is given without any viscosity reducer added. The preparation, conversion and maintenance of the fluid in drilling an evaluation well, Xianhe-4, are presented in some detail. With this fluid in drilling the pipe string pulls out and goes down and drilling job starts smoothly; whole sand samples are recovered; the average borehole enlargement is of 5.6% and the maximal borehole contraction is of 2.8% ; electric logging is performed successfully; the core yield is of 97.65% ; the rheologic behavior of the fluid is readily controllable; the drilling time is shortened to 60 days.

关 键 词：海水基钻井液 氯化钾钻井液 钻井液设计 易坍塌地层 辽河滩海地区 仙鹤4井 

分 类 号：TE254.6[石油与天然气工程—油气井工程]