关键词: 秘鲁1AB/8区块, 强天然水驱, 特高含水率, 污水, 回注技术, 地层破裂压力, 经济效益

Abstract: The daily re-injection amount of produced water is 170000 cubic meters in Block 1AB/8 of Peru,which is the strong natural water driving and extremely high water-cut oilfields.In order to reduce the expensive cost,the outside part of Vivian reservoir and the neighbor Pozo sandstone reservoir were selected as water re-injection zones without contamination to shallow fresh water and enough capacity for the high volume re-injection water.Reducing the percentage of suspended solid and remaining oil in the produced re-injection water,increasing the perforation interval and density,and reducing the pressure lost along the injection tubing could sustain the high rate of water re-injection.According to the calculation of formation fracturing pressure,the injected formation could be fractured under a wellhead injection pressure ranged from 12.4MPa to 17.2MPa.Six pilot injection wells were tested with more than 6360 cubic meters re-injection of produced water per day in one well.The monitoring data of six wells showed that the fractured injection zone could keep high injection rate under a low wellhead pressure.The improved water re-injection plan with increasing water injection rate has achieved a good economic benefit.

Key words: 1AB/8 Block in Peru, strong natural water driving, extremely high water cut, produced water, re-injection technology, formation fracturing pressure, economic benefit