体膨颗粒深部调剖技术及其在大庆油田的应用

Swellable in Water Particulated Crosslinked Polymer for Indepth Profile Modification in Daqing

大庆三大主力油田已进入高含水、高采出程度开采阶段 ,油藏内已出现高渗透大孔道 ,必须进行封堵。选用交联聚合物颗粒作为深部调剖剂。从三种颗粒剂中筛选出的颗粒剂WT ,在自来水中 2 4h膨胀倍数为 80～ 90 ,抗压强度为 0 .8～ 1.2MPa,可形成胶结体 ,在渗透率 3～ 3.5 μm2 的岩心中突破压力梯度为 10 .7MPa/m ,在油田污水中膨胀倍数下降至 6 0～ 80 ,抗压强度基本不变。所用颗粒剂的粒径由区块典型井和选定的施工井现场试注压力 时间曲线求得 ,为 2～ 5mm。介绍了在杏北油田 3口注水井实施颗粒剂WT深部调剖的工艺和结果。颗粒剂用注入水携带 ,连续注入注水井。在X7 2F35井 ,颗粒剂在注入水中的质量浓度为 5 .3kg/m3 ,总注入量为 6 0 93m3 ,设计调剖半径 2 1.5m。实施深部调剖后 3口注水井在平面和纵向上的吸水剖面都获得了很大改善 ,一些连通油井产油量增加 ,含水量有所下降。图 6表 4。

The oil production at 3 main oil fields of Daqing is in their stage of high water cut and high percentage recovery and high permeability channels and passages are created in depth of the reservoirs and necessary to be plugged. Particulated crosslinked polymers (PCLPs) are chosen as plugging/profiling agent. Being selected from 3 such polymers, PCLP WT is characterized by following experimental data: the particles expand in volume 80-90 times in tap water in 24 hrs; the swelled particles have compression strength of 0.8-1.2 MPa and, forming a bulcky mass, create blockages with breakthrough pressure of 10.7 MPa/m in cores of permeability 3-3.5 μm^2; the expansion in volume in an oilfield produced water in 24 hrs is decreased to 60-80 times and the strength of the swelled partictes remains unchanged. The particle size of the crosslinked polymer, being of 2-5 mm, is determined on the basis of injection pressure-time curves obtained in trial injection into a typical well of the reservoir and the aimed well. The technologic aspects and the results of the indepth profiling operations with PCLP WT in 3 injection wells of Xingbei oil field. PCLP WT is injected into the wells continuously with the injection water. For well X-7-2F35, the concentration of WT in water is of 5.3 kg/m^3, the tolal volume injected - 6093 m^3 and the designed treating radius - 21.5 m. The water entry profile, both planar and vertical, of these wells are greatly improved after the operations performed and increase in oil productivity and decrease in water cut are observed for some connected production wells.