中低温缓凝剂的研究与应用

Research and application of moderate and low temperature retarder

在长庆致密油开发区域水垂比基本大于1:1,水平段地质特点高含水、井温低(≤65℃)。长水平段固井需要水泥浆具有较长的稠化时间和高早期强度等特点。目前使用的淀粉类缓凝剂在中低温条件下缓凝效果线性关系差、且对水泥石早期强度破坏大。通过室内研究研发出以AMPS和羟基羧酸盐复合作为单体,配以高分子分散剂、增强材料形成中低温缓凝剂GJ-H。该缓凝剂体系具有温度使用范围宽(40℃~90℃)、在中低温可有效延长稠化时间、早期强度高(40℃8 h时强度达到8.2 MPa)、过渡时间短、稠化时间易调等优异的综合性能。研制的GJ-H在长庆油田油井、气井、水平井已完成现场施工30口井,一次合格率为100%。固井效果良好,解决特殊工艺施工和制约长水平段水平井高效推广应用的瓶颈。

In the Changqing dense oil development area, the water droplet ratio is basically greater than 1：1, and the geological characteristics of the horizontal section are high in water content and low in well temperature（≤65 ℃）. Long horizontal cementing requires long thickening time and high early strength of cement slurry. The starch retarder used at present has a poor linear relationship with the effect of retarding under medium and low temperature conditions, and has a great damage to the early strength of cement stone. We have developed the AMPS and hydroxycarboxylate compound as monomers,together with polymer dispersants and enhanced materials to form medium and low temperature coagulants GJ-H through indoor research.The system has a wide range of temperature use（40 ℃～90 ℃）, can effectively extend the thickening time at medium and low temperatures, high early strength（8.2 MPa at40 ℃ 8 h）,short transition time, and easy to adjust the thickening time.The developed GJ-H has completed on-site construction of 30 wells in Changqing oilfield, gas wells, and horizontal wells, with a pass rate of 100 %. The results of well fixation are good, which solves the bottleneck of special process construction and restricting the application of horizontal well in long horizontal section.