抗高温有机酸盐完井液研究

High Temperature Resisting Well Completion Fluid of Organic Acid Salt

霍宝玉 成挺 张晓崴 王光平 刘大海

HUO Bao-Yu CHENG Ting ZHANG Xiao-Wei WANG Guang-Ping LIU Da-Hai

针对元坝超深井试气测试过程中存在的问题，结合区块储层特点，优化得到抗温170℃的有机酸盐完井液配方：HCOONa(密度1.30 g/cm3)或HCOONa、HCOOK复合盐（密度1.50 g/cm3）基液+0.5%改性黄原胶增黏剂DHV+2%低黏聚阴离子纤维素降滤失剂PAC-142+1%酸性缓蚀剂SD-2+0.8%两性离子型助排剂SAT+0.2% NaOH+0.5% Na2SO3。该有机酸盐完井液160℃静置恒温稳定时间达64 h，耐温黏度降低率小于50%，API失水量小于16 mL，160℃高温高压失水量小于30 mL，对P110钢的腐蚀速率低于0.05 mm/a，岩心渗透率恢复率为86.5%~88.0%，可有效降低测试过程中入井流体对油气层的伤害，避免高温高压井况下因固相沉降、工作液抑制能力降低而引起的试气测试井下事故的发生。

According to the reservoir characteristics, the optimized formula of well completion fluid of organic acid salt with resistance of high temperature 170℃ was established: HCOONa (density of 1.30 g/cm3) or HCOONa, HCOOK compound salt (density of 1.50 g/cm3 ) base fluid, 0.5% modified xanthan gum adhesion promoter DHV, 2% polyanionic cellulose fluid loss agent PAC-142 with low adhesion, 1% acid corrosion inhibitor SD-2, 0.8% amphoteric ionic cleanup additive SAT, 0.2% NaOH, 0.5% Na2SO3. After standing at 160℃, the stabilization time of this organic acid salt completion fluid was 64 hrs, the viscosity reduction rate was less than 50％, API fluid loss was less than 16 mL, and HTHP fluid loss was less than 30 mL at 160℃. The average corrosion rate of P110 steel was less than 0.05 mm/a and the core permeability recovery rate was about 86.5%—88.0%. The damages to hydrocarbon reservoir by fluid in well during the test could be effectively reduced by the well completion fluid. Additionally, the underground accidents happened in the process of gas test, which caused by solid settlement and the inhibition capacity reduction of working fluid on well condition of high temperature and high pressure, could also be avoided.