BX水泥浆体系在LN油田的应用

为了实现钻井"提速、降本、增效"，塔里木油田优化了LN油田的开发/评价井的井身结构，减少套管层数，形成了较多的长裸眼固井。而长封固段固井中的高温高压、大温差、长裸眼段、多套压力层系并存等复杂情况极大地增加了固井难度，对水泥浆的各项性能要求更为严格。从LN油田低压易漏长裸眼段固井的难点出发，结合该区域目前广泛采用的工艺技术现状，水泥浆的应用情况，进行了BX水泥浆体系应用适应性评价。结果表明，BX水泥浆体系具有高初始稠度、强触变性、防窜性能好等特点，更能够适用于LN油田的地质特征，在水泥浆候凝期间起到一定的防漏堵漏作用。双密双凝水泥浆设计，能有效降低液柱压力，降低施工过程中压漏地层的风险，提高整体固井质量，能够满足低压裸眼长封固段固井需求。 

Application of BX Cement Slurry in Block LN of Tarim Oilfield

Tarim Oilfield has done a lot of work to optimize the casing program of development well and appraisal well in block LN to achieve "fast, cost saving and efficient" drilling. Reduced number of casing strings result in long open hole section with cementing difficulties such as HTHP, large temperature difference and coexistence of multiple formation pressures, which in turn impose more rigorous requirements on the properties of cement slurry. Based on the difficulties encountered in the past in cementing long lowpressure open hole section in which mud losses are easy to occur, and the well cementing techniques commonly used in block LN, laboratory experiments were conducted to evaluate the adaptability of BX cement slurry to the practical situation in that area. It was found that BX cement slurry had high initial consistency, strong thixotropy and good anti-channeling capacity, and was thus compatible with the geologic nature of the block LN. The cement slurry, during WOC, was able to prevent mud losses from occurring. The cement slurry was designed to have two densities and two thickening times, effectively reducing the liquid head of cement slurry, and in turn reducing the risks of lost circulation during operation. With this technique, the job quality of well cementing has been improved and the needs for cementing long low-pressure open hole section have been satisfied.