低压、低渗气藏压裂改造化学增能技术

FRACTURING TREATMENT TECHNOLOGY TO ENERGIZE CHEMICALLY FOR LOW-PRESSURE AND LOW-PERMEABILITY GAS RESERVOIRS

根据中原油田文23气田储层渗透率低、压力系数低、返排率低、压裂措施后压裂液滞留地层中对储层造成伤害等地质特征，研究了化学增能工艺技术，利用化学反应产生大量的气体和热量来减缓或解除液体的滞留，从而达到提高返排、减少储层伤害和提高工艺效果的目的。实验研究了自生气体剂自生热化学剂组分、配方优选和性能评价等方面。研究表明：80℃条件下，90min可使密闭容器中含有1．0mol／L自生气体剂水溶液的压力达到1·92MPa在液体起始温度为10℃的条件下，可使液体温度在10～20min升高到95℃。另外，通过自生热化学剂发生反应生成的泡沫质量为92．7％，而且具有良好的稳定性，半衰期在28．9min。现场试验表明，该技术取得了良好的应用效果。

Based on the geologic characteristics of reservoirs with low permeability,low pressure coefficient,low back-flow efficiency and the damage caused by retention of fracturing fluid in the gas well Wen-23 of the Zhongyuan oilfield,the paper studied the technology of energizing chemically i.e.,by chemical reactions,a great quantity of gas and heat is generated to slow down or dissolve the fluid retention,so as to achieve purposes of increasing back-flow,reducing the damage to reservoir and improving the effectiveness of technology.Experiments studied some aspects,such as compositions of autogenetic gas and thermochemical agents,formulation optimization,performance evaluation and so on.Research showed that:under the condition of 80 ℃,the pressure of aqueous solution with 1.0 mol/L autogenetic gas agent in the closed container can reach 1.92 MPa within 90 min;under the condition of 10 ℃ as the initial temperature of liquid,the liquid temperature can be increased to 95 ℃ within 10 to 20 min.In addition,the foam quality obtained by the reaction of autogenetic thermochemical agents is 92.7% and has a favorable stability within 28.9 min as its half-life.Field tests indicated that the technology has got a good application result.