低渗透油田高压注水开发探讨

High-pressure water injection in the development of low-permeability oilfields

张春荣

Zhang Chunrong

胜利油田分公司清河采油厂，山东 寿光 262714

Qinghe Oil Production Plant, Shengli Oilfield Company,SINOPEC,Shouguang 262714, China

为了提高严河油田低渗透油藏的采收率，增加可采储量，通过采用高压注水方式，改善了低渗透油藏的注水开发效果。低渗透油藏在注水开发过程中受毛细管压力、贾敏效应的影响很大，随着渗透率的降低，毛细管压力较高，其微观水驱油特征表现为连续的油很容易在喉道变径处卡断，变成不连续的油滴，必须要有足够的压差才能克服其阻力效应将油驱出。因此，低渗透油藏的注水开发必须使用相对的高压注水，这样才能在理论上提高波及系数10%~25%，从而使采收率提高3%~4%。研究结果表明，严河油田最终采收率提高了25个百分点，增加可采储量29.5×104 t。

In order to enhance the oil recovery of low permeability in Yanhe Oilfield and increase recoverable reserves, high-pressure water injection is selected to improve the development effect of low-permeability reservoir. During waterflooding, low-permeability reservoir is affected greatly by capillary force and Jia Min effect. As permeability decreases, capillary pressure will be higher and continuous oil in the micro waterflooding is easily to be cut off where the radius of throat is changed. And the continuous oil will become discontinuous oil drops. In this case, enough pressure is needed to overcome the resistance effect to drive out the oil
droplets. So a relatively high-pressure water injection must be used during the waterflooding in low permeability reservoirs in order to improve the sweep efficiency to 10%~25% in theory, and increase recovery rate by 3%~4%. The results show that ultimate recovery of Yanhe Oilfield has increased by 25%and the recoverable reserves increased 29.5 ×10⁴t.