包14块低渗透油藏注CO2开发效果研究

包14块为不均匀型低渗﹑特低渗储层,采用注水开发含水上升块,而且水敏现象严重。通过室内实验,研究了包14块进行CO2驱可行性。实验结果表明:地层条件下,CO2与包14块地层油的最小混相压力为21.4 MPa,高于地层压力。CO2混相驱(23.5 MPa)和非混相驱(12.5 MPa)最终采收率分别为82.39%和73.78%,混相驱比非混相驱CO2突破时间少0.125PV;注气量大于0.3 PV后,混相驱的换油率明显高于非混相驱;注气压力越大,CO2注入能力越强。可见,尽管在地层条件下,CO2与地层油不能达到混相,进行CO2非混相驱仍可取得非常好的效果。

The Development Effect of CO2 Flooding on Low Permeability Reservoirs in Bao 14 Block

Bao 14 block is the uneven type of low and ultra-low permeability reservoirs, water cut rises rapidly after use water injection, and water sensitivity phenomenon seriously. Through the indoor experiment in the text, we studied the feasibility CO2 flooding in Bao 14 block. The experimental results show that in the reservoir conditions, the MMP of CO2 and the oil in the Bao14 is 21.4MPa, which is higher than the reservoir pressure. The ultimate recovery of miscible phase recovery of CO2 (23.5 MPa) and the immiscible displacement (12.5 MPa) is 82.39% and 73.78%, the breakthrough time of miscible phase recovery is less than immiscible displacement 0.125 PV; The oil/gas exchange ratio of miscible phase recovery is obvious higher than immiscible displacement when gas injection volume is more than 0.3 PV. The higher injection pressure of gas, the stronger absorption capability of CO2.It is clear that although in reservoirs conditions, CO2 and oil can not reach miscibility. It still be very good effect through immiscible displacement of CO2.