亲水砂岩油藏注水吞吐开发模式探讨

大港油田南部地区的油藏大多为复杂断块油藏，油藏内部断层多．由于断块面积小而封闭、储集层低渗透、原油黏度高而注水驱替难度大．注水井投注一段时间后往往出现憋压注不进的现象，受益油井见不到注水效果。该娄油藏可充分利用其砂岩的亲水性，根据亲水介质的自吸排油机理，对生产井周期性地先注水后采油，进行注水吞吐开发．来提高油藏最终采收率。王官屯油田王261断块(低渗透油藏)和自来屯油田自1914断块(稠油油藏)均为亲水性复杂断块油藏．在先导性试验成功的基础上，实施了以注水、关井、采油为一个周期的注水吞吐开发模式，2个断块吞吐累计增油2．2万t以上。图2表4参10

Discussions on developing hydrophilic sandstone reservoir by water injection-production

Most reservoirs of the south Dagang Oilfield are complex fault block pools with faults developed in the reservoir. The blocks are small and closed, the reservoir permeability is low and oil viscosity is high, which makes it difficult to displace oil by water flooding. Soon after injectors are brought into production, the injection pressure is increased rapidly. Meanwhile, the injectivity decreases dramatically, which leads to little benefit to corresponding oil wells. For this kind of reservoir, hydrophilic property of the sandstone could be used advantageously. According to the spontaneous imbibition expulsion mechanism of the sandstone, the higher recovery efficiency could be obtained by water injection-production. Wang 26-1 block of Wangguantun Oilfield is of low permeability, and Zi 19-14 block of Zilaitun Oilfield is of high viscosity, and both are hydrophilic complex block pools. On the success of pilot test, the development mode of water injection-production had been used in this way and oil production increment of the two blocks reached over 22,000 t.