定北区块抗高温钻井液体系优化

Optimization of High Temperature-resisting Drilling Fluid in Dingbei Block

摘要:

定北区块储层深埋温高导致常规钻井液体系失效且复杂情况多发，研制一套抗高温钻井液体系已成为解决定北区块钻井复杂情况多发的重要途径。总结分析定北区块钻遇复杂情况及钾铵基钻井液体系性能测试结果，明确了钻井液优化方向——抗高温抑制性、稳定性、降滤失性和封堵能力。针对目前现场常用多种抗高温钻井液处理剂开展了流变性、滤失性、封堵性、润滑性等性能测试实验，优选SMC和SPNH作为抗高温降滤失剂、KCl和聚胺作为抗高温抑制剂、HQ-10作为抗高温封堵剂、白油及石墨作为抗高温润滑剂、SF-1作为抗高温稀释剂，并得出最佳土粉含量为4%，最终得到了抗高温钻井液体系配方。室内性能评价实验表明，该抗高温钻井液体系在180 ℃热滚72 h后粘度、切力及失水仍满足设计要求，且抗NaCl及CaCl2污染分别达到10%和4%，储层岩心伤害渗透率恢复值可达80%以上。定北抗高温钻井液配方的形成将为定北区块安全高效钻进提供保障。

Abstract:

The failure of conventional drilling fluid system and multiple complex situations caused by deep reservoir with high temperature in Dingbei block, it is necessary to develop a set of drilling fluid with high temperature tolerance. Through analyzing the essentials of well drilling incident and the properties of potassium ammonium based drilling fluid, it is clear that the drilling fluid should be improved in high temperature inhibition, stability, filtration reduction and sealing ability. A lot of high-temperature drilling treatment agents have been tested in rheology, filtration, sealing and lubrication, SMC and SPHN are chosen as anti high temperature flirtation reducer, KCl and polyamine as anti high temperature inhibitor, HQ-10 as anti high temperature plugging agent, white oil and graphite as lubricant, SF-1 as anti high temperature diluent; the appropriate bentonite content is determined to be 4%, the high temperature drilling fluid system formula is finally obtained. The laboratory evaluation experiment shows that the viscosity, shear and water loss of this high temperature drilling fluid can still meet the design requirements after 180℃ hot rolling for 72h and anti-contamination of NaCl and CaCl2 are 10% and 4% respectively, the permeability recovery rate of damaged reservoir core can reach more than 80%. This high temperature drilling fluid formula will provide support to safe and effective drilling in Dingbei block.