注水处理用粘土稳定剂的优选

To optimize day stabilizing agent for water injection treatment.

油井转注水前必须对油层进行防膨处理,而选择合适的粘土稳定剂是关键。由于粘土稳定剂传统评价方法存在不足以及现场使用存在随意性,因此建立了优选粘土稳定剂的系统评价方法。即用X射线衍射仪测定经不同浓度的粘土稳定剂浸泡过的Ca蒙脱石的晶面间距,确定粘土稳定剂最佳的使用浓度;采用乙二醇蒸汽饱和法、水洗实验法、水浸泡实验法评价粘土稳定剂防膨效果的稳定性和耐水冲刷能力;测定在不同温度下经最佳浓度的粘土稳定剂处理后的Ca蒙脱石晶面间距,了解粘土稳定剂的稳定性能;使用研究区块岩心并模拟注水过程进行岩心流动实验,优选出适合于具体区块注水前预处理用的粘土稳定剂。在低渗透油田河146区块,采用优选的粘土稳定剂对河2-斜4井处理后,平均注水量为60.2m3／d,注水油压为18NPa;而没有采用优选的粘土稳定剂的河146-63井,在油压为29MPa时还注不进水。实践表明所建立的粘土稳定剂的系统评价方法是有效的,对油田粘土稳定剂的使用具有一定的指导意义。

Antiswelling treatment of oil reservoirs should be done before oil well begins to water injection. Selecting suitable clay stabilizing agent is the key. A systematic evaluation method for optimizing clay stabilizing agent was built for the shortcomings and randomness of field use in the traditional methods. Using X ray diffractometer to measure crystal plane space of calcium-montmorillonite soaked by clay stabilizing agents with different concentrations,then optimal used concentration of the clay stabilizing agent was ascertained;Using methods of glycol vapor saturation,water washing experimentation and water soaking experimentation to evaluate stability of antiswelling effect and water brushability of the clay stabilizing agent;Crystal plane space of calcium-montmorillonite treated by optimal used concentration of the clay stabilizing agent was measured at different temperatures, and then the stability of the clay stabilizing agent was known;Core flow test was carried out using studied block core and simulating the water injection process so as to select suitable clay stabilizing agent for pre - treatment before water injection in the studied blocks. After optimized clay stabilizing agent was applied in He2-xie4 well of Hel46 block in low permeability oilfield, average water injection rate is 60. 2m3/ d, and oil pressure when water injection is 18MPa. Even at 29MPa water cannot not injected into the Hel46 -63 well which did not use the optimal clay stabilizing agent. This shows that the systematic evaluation method for the clay stabilizing agent is effective , which will have guiding significance on the application of clay stabilizing agent to oilfield.