连续油管新型钻塞胶液在JY25-1HF井的应用

在连续油管钻磨桥塞施工中，由于连续油管设备及钻塞液的限制，钻屑难以返出井口，易出现憋泵、卡钻等复杂情况。为此，对现有连续油管钻塞液进行优化改性，引入多糖类高分子化合物为流型改性剂，通过材料优选及性能对比，研发出新型钻塞胶液。通过判别，该新型胶液属于幂律流体，计算得出，原钻塞胶液在管柱内和环空内均为紊流，循环压耗均为0，而新型钻塞胶液在管柱内为紊流，在环空内为层流，而循环压耗分别为1.7 MPa、0.116 MPa。新型钻塞胶液在涪陵JY25-1HF井连续油管钻磨桥塞施工中进行了试验应用，在注入10 m3时循环泵压最高，为1.80 MPa，与理论计算结果基本吻合，误差在1.80%。应用效果表明，新型钻塞胶液综合携带能力显著提高，携带量提高了2倍以上，值得进一步推广应用。 

Drill Bridge Plug with a New Fluid in Coiled Tubing Operations in Well JY25-1HF

When drilling the bridge plugs in coiled tubing operations, the limitations from the coiled tubing equipment and the drilling fluids always hinder the return of drilled cuttings which in turn causes problems such as overpressure pumping and pipe sticking etc. To avoid these problems, a polysaccharide polymer has been introduced into the drilling fluid, and, by carefully select materials used in the drilling fluid and performance evaluation, a new drilling fluid has been developed for use in the drilling of bridge plugs. As a power law fluid, the pipe flow of it is of turbulent flow, and flow in annular space is of laminar flow, showing stark contrast with the old drilling fluid which is of turbulent flow both in annular space and in pipe. The new drilling fluid has circulation pressure losses of 1.7 MPa and 0.116 MPa in pipe and in annular space, respectively, while the circulation pressure loss of the old drilling fluid is 0 MPa both in pipe and in annular space. The new drilling fluid has been tried in Well JY25-1HF. The highest pump pressure, 1.80 MPa, was achieved when pumping 10 m3 drilling fluid into the hole, very close to the calculation, with an error of 1.80%. The application of the new bridge plug drilling fluid has demonstrated that it has better carry capacity, more than 3 times of the old drilling fluid, and can be introduced to other area where bridge plugs are to be drilled.