受CO_(2)污染的钾聚磺钻井液体系维护工艺研究

Study on Maintenance Technology of Potassium Polysulfonate Drilling Fluid System Contaminated by CO_(2)

针对钻井过程中钾聚磺钻井液体系受CO_(2)污染后性能发生突变等问题,分别探索了CaO法、有机胺吸收剂调节法以及pH调节法这三种工艺对钾聚磺钻井液体系性能的维护效果,实验发现优化加量后能够发挥维护作用,但无法满足现场要求。对比发现CaO法维护效果相对较好,因此室内通过优化Ca^(2+)配体合成了螯合钙1和螯合钙2,实验发现两者维护后均能使性能达到现场需求,但螯合钙2相较螯合钙1溶解度较好,加入体系内对体系粘切影响较小,在钻井液中加量仅为2%时便可使FL_(HTHP)从32.4 mL降至9.6 mL,极大地削弱了CaO维护时增大了体系无用固相从而带来的影响,弥补了传统方法的不足,能够更好地满足现场的钻进需求。为现场受CO_(2)污染的钻井液维护工作提出了建议。

To solve the problem of sudden change in the performance of potassium polysulfonate drilling fluid system contaminated by CO_(2)during drilling,CaO method,organic amine absorbent adjustment method and pH adjustment method were explored to maintain the drilling fluid performance.It was found that the proper amount of potassium polysulfonate drilling fluid system can play a maintenance role,but cannot meet the field requirements(FL_(HTHP) was 15 mL).By comparison,it was found that the maintenance effect of CaO method was relatively good,so chocolate calcium 1 and chocolate calcium 2 were synthesized by optimizing Ca^(2+) ligands in the laboratory.It was found that both chelate calcium 1 and chelate calcium 2 can meet the field requirements after maintenance,but the solubility of chelate calcium 2 was better than that of chelate calcium 1,and the addition of calcium chelate to the system had little effect on the viscous shear of the system.When the amount of drilling fluid was only 2%,the filtration loss can be reduced to 9.6 mL.It greatly weakens the influence caused by increasing the useless solid phase of the system during CaO maintenance,made up for the shortcomings of traditional methods,and can better meet the drilling needs of the field.Some suggestions were put forward for the maintenance of drilling fluid contaminated by CO_(2) in the field.