底水油藏水平井射孔密度优化

Horizontal Well Perforation Density Optimization in the Reservoirs with Bottom Water

水平井开发底水油藏时,水平井筒内因流体的变质量流动而引起压力降,从而使沿水平井段的流量剖面不均匀,对于非均质性严重的油藏,这种现象更加明显。这将会导致许多生产问题如底水的早期突破等,会大大降低油藏采收率。在考虑井筒内压降的基础上对底水油藏渗流及井筒内流动进行了研究,建立了射孔水平井底水油藏模型、井筒压降模型及其油藏/井筒耦合模型。针对压降带来的生产问题,提出了一种新的优化射孔孔密分布的方法,均衡了沿井筒的流量分布。利用水平井射孔优化设计软件,对某非均质严重的水平井进行了孔密优化设计,证明了此孔密分布优化模型的正确性和实用性。

When reservoirs with bottom water were produced by using horizontal wells,pressure drop would be induced in the wellbore because of variable mass flow causing non-uniform inflow profile along the wellbore.For reservoirs with severe non-homogenety,this effect would be more obvious,it would result in a number of production problems,such as water/gas coning breakthrough early to decrease the recovery ratio greatly.On basis of considering the wellbore pressure drop,the fluid flow through porous medium in bottom water drive reservoirs and flow in the wellbore were analyzed.A bottom water reservoir model and a model of pressure drop in the wellbore and reservoir-wellbore coupling model were built.In allusion to the problem of pressure drop,a new optimal design of perforation density distribution is made to equalize the inflow profile along wellbore.By using optimized perforation software of horizontal well,a design for optimizing perforation density of a horizontal well with severe inhomogeneity is made to simulate the model,it proves to be correct and practicable.