提高高渗欠压层固井质量的技术与应用

分析认为，大庆长垣油田高渗欠压层固井质量差的原因是水泥浆中的水分大量流失后，水泥吸收井壁泥饼的水分造成泥饼龟裂脱落。为提高高渗欠压层的固井质量，采取了一系列技术措施：根据环空压差小于7．2MPa。高渗欠压层水泥胶结指数大于0．8，确定高渗欠压层洗井液的密度；减小层间压差，进行压力剖面调整。现场应用表明，采取这两种技术措施后，高渗欠压层的固井质量得到了提高。

Technology and Application of Enhancing Cementing Quality for Highly Permeable and Weak Zones

That severe fluid loss of cement siurry makes it gets water from mud cake, and thus the mud cake will chap and fall off down because of deficient water contents, which result in bad cementing quality at highly permeable and weak zones in the Changyuan Block in the Daqing Oilfield. In order to enhance cementing quality, a series of measurements are employed, including optimizing density of flush water according to annular pressure difference less than 7.2 MPa and cement exponent over 0.8 at high permeability and weak zones, controlling pressure profile to reduce pressure difference between zones. Field applications indicate that the cementing quality at such situation is improved considerably after employing such measures.