摘要
针对海上高压低孔渗油气田固井注水泥候凝时气窜、储层压裂后水泥环破裂等问题,经数值模拟分析压裂作业所需水泥石的性能参数,通过加入胶乳、纤维和膨胀剂等材料,降低弹性模量,增加抗拉强度,达到防收缩防产生间隙的目的,研制了海上增韧防窜固井水泥浆体系。室内评价结果表明,该水泥浆体系的密度为1.65~1.85 g/cm3,API失水量小于50 m L;稠化时间在3~6 h可调;游离液为0,具有良好的施工性能,满足作业要求。水泥石24 h抗压强度大于14 MPa;杨氏模量为3~5 GPa;泊松比为0.13~0.20,满足了压裂对水泥石韧性的要求。该体系弹性模量较常规水泥石降低了约50%,抗拉强度提高了10%左右,增韧防窜性能优良。该体系在东海多口井现场应用,固井质量优良,满足了防气窜和压裂作业的需要。
High pressure offshore wells with low porosity and low permeability reservoirs always encountered gas channeling during wait-on-cementing(WOC) and cement sheath breakdown after fracturing. A new cementing slurry with enhanced toughness and antichanneling capacity was developed to deal with these problems. The preparation of this new cement slurry was based on the numerical analysis of the properties of set cement necessary for fracturing operation, and other improvement such as the use of latex, fiber andexpansion agent. The set cement thus had elastic modulus reduced by 50% and tensile strength increased by 10%, and had improved anti-channeling capacity. This cement slurry formulation had been successfully used in well cementing in Donghai block, satisfying the need for gas channeling prevention and fracturing operation.
出处
《钻井液与完井液》
CAS
北大核心
2015年第4期59-62,108-109,共4页
Drilling Fluid & Completion Fluid
基金
中国海洋石油总公司重大科研项目"东海低孔渗油气田勘探开发工程技术研究及应用"(CNOOCKJ125ZDXM07LTD06SH2012)
关键词
水泥浆
固井
防窜
增韧
Cement slurry
Well cementing
Anti-channeling
Toughness enhancing
