水平井化学堵水配套药剂研究

Chemicals for Water Shutoff in Horizontal Wells

针对水平井化学堵水需要,研发了3种化学剂。一是化学环空封隔材料,由可溶性淀粉、丙烯酸、交联剂、淀粉酶、引发剂等在水溶液中聚合而成,讨论了合成条件。35%、45%的反应混合物1PV注入填砂管,在60℃聚合48或24小时,水测突破压力梯度>30MPa/m。聚合产物有弹性,在水中发生溶胀、降解和溶解,最终产物包括未溶解、部分溶解的淀粉、多糖、短链聚丙烯酸等,固体物粒径<100μm,降解96小时后黏度4mPa·s,降解时间随温度升高(3585℃)而减小(从约100小时到约20小时)。二是聚合物铬凝胶,聚合物为北京恒聚的耐温抗盐聚合物,无机铬交联剂中的还原剂亚硫酸盐为工业副产物,加有0.01%无机强还原剂。三是无机强造壁封堵剂,由G级油井水泥、硅灰、超细水泥、聚丙烯纤维组成,凝固时间38小时,抗压强度>12MPa。

Three chemical agents were presented for water shutoff in uncemented horizontal wells completed with slotted liner. The polymerizing mixture for building annular chemical packer（ACP） was composed of water soluble starch, acrylic acid, crosslinker, amylase, and initiator in aqueous solution and its polymerization parameters were discussed. The sand packs with 1 PV of the polymerizing mixture containing 35% or 45% reaction chemicals injected and after reaction at 60% over 48 or 24 hrs gave breakthrough pressure 〉 30 MPa/m. The polymerization product was elastic solid mass and the swelling, degradation, and dissolution in water occured simultaneously to give unsolved and partially solved starch, polvsaccharides, short chain oolvaervlie acid：ere asdegradation products ; the particle size of solid substances was of 〈 100 μm ; the viscosity of the liquid mixture degraded in 96 hrs was of 4 mPa· s ;the time needed for polymer degradation to be completed was reduced with raising temperature：about 100 hrs at 35℃ and about 20 hrs at 85℃. Another chemical agent was a polymer/Cr3＋ gelling fluid, in which Beijing Hengju＇s salt-tolerant comb-like acrylamide copolymer,low cost industrial byproduct sulfite as reducer with 0. 01% inorganic strong reducer as catalyst were used. The third was an inorganic wall-building slurry, composed of G grade oilwell cement, wollastonite powder, uhrafine cement, and polypropylene fiber,gelated in 3--8 hrs to give set cement of compression strength 〉 12 MPa.