纤维水泥堵漏性能评价研究

Laboratory Evaluation of Fiber Cement in Resuming Lost Circulation

水泥浆漏失低返一直是影响固井质量的技术难题,使用纤维水泥是解决这个问题的有效方法,而目前缺少对纤维水泥堵漏性能进行评价的试验装置和评价方法。以水泥浆高温高压失水仪为基础建立了水泥浆堵漏试验装置,该装置可以进行渗透性和裂缝性地层堵漏模拟试验,具有用浆量少、操作方便、可以加热等特点。通过参考钻井用桥接堵漏材料室内试验方法,结合API水泥浆性能测试规范,制定了水泥浆堵漏性能评价方法。利用该方法对BCE-200S纤维水泥浆堵漏性能进行了评价,结果表明,纤维材料在助防漏剂的协助下可以对1 mm孔隙或1 mm缝隙模块实现迅速封堵,漏失量小于50 mL,承压能力达到3.5 MPa以上。

Lost circulation and low return velocity of cement slurry are difficult problems affecting the quality of oil well cementing jobs,while the fiber cement can be used to solve these problems.No experimental apparatus and methods are currently available to evaluate the performance of fiber cement in sealing lost circulation zones.This paper introduces a lost circulation evaluation device modified from a HTHP filter press for cement slurries.Seepage loss and loss into fracture can be simulated on this evaluation device.Volume of mud used for the evaluation is reasonably low.This device is easy to operate and can also be heated to the desired temperatures.The evaluation method was developed based on the evaluation method for bridging LCM and API cement slurry testing method.Using this evaluation device and method,the BCE 200S fiber cement was tested in laboratory.The test results show that fiber materials,with the aid of secondary LCM,can seal effectively and quickly fractures or openings 1 mm wide or in diameter,with water losses being less than 50 mL,pressure containment being higher than 3.5 MPa.