高密度半饱和盐膏层固井水泥浆体系构建及其综合性能研究

Study on Construction and Comprehensive Performance of High Density Semi Saturated Salt Gypsum Layer Cementing Slurry System

深水巨厚含盐储层的固井作业中所存在的盐蠕动问题多年来一直是一项技术难题,此外,除了需要解决抗盐性问题的同时还需要针对性进行加重以平衡深水下的地层压力。本文通过以半饱和盐水为基浆,采用多元加重剂组合形式对水泥浆进行密度区间1.9~2.4 g·cm-3的浆体设计,同时对水泥浆一系列基础性能及力学性能进行系统性评测及分析,构建出一套能有效满足变密度深水巨厚盐层的固井水泥浆配方体系,该套配方体系在120℃下具有良好的流动性,且稠化时间大于3 h,失水量低,24 h抗压强度稳定在20 MPa以上,具有较好的应用效果和价值。

The salt creep problem in cementing operation of deep-water extremely thick salt bearing reservoir has been a technical problem for many years.In addition,in addition to solving the problem of salt resistance,it is also necessary to carry out targeted weighting to balance the formation pressure in deep water.In this paper,based on the semi saturated salt water as the base slurry,the slurry with density range of 1.9~2.4 g·cm-3 was designed by the combination of multiple weighting agents.At the same time,a series of basic properties and mechanical properties of the cement slurry were systematically evaluated and analyzed,and a set of cementing slurry formula system which can effectively meet the variable density deep water extremely thick salt layer was constructed.It has good fluidity,thickening time of more than 3 h,low water loss and compressive strength of more than 20 MPa in 24 h at 120℃.