In order to develop low permeability oil reservoir on offshore oilfields effectively, one special development mode of " near production and far injection " of aritificial fracture for horizontal wells fracturing is adopted, that is fractures of far end were injected water and near end fractures produce oil of fractured horizontal well. Based on oil-water two phase seepage characteristic of oil reservoir and hydraulic fracture and considering the variation of fracture conductivity with time, forecast mathematical model of the oil and water production of " near production and far injection " production model is established, in the model, reservoir and fractures are in same fluid flow system. Finite difference method is applied to discretize mathematical model so that to obtain corresponding numerical model and IMPES method is selected and used to solve the mathematical model, a numerical simulator is developed by themselves. The research indicated that in a certain producing period, the smaller fracture spacing, the higher daily oil production, but eventually cumulative oil yield increased along with the increase of fracture spacing, therefore , it would be better to expand fracture spacing when stimulated; the higher fracture conductivity, the higher daily oil production and cumulative oil production, but the time when fracture produced water largely would be advanced , the increasing extent would also drop; the length and conductivity of the aritificial fracture of the reservoir is optimized, in order to obtain superior stimulation effect , the enhancement of fracture conductivity should be given priority to.%为有效开发海上低渗油藏,采用了压裂水平井人工裂缝“近采远注”特殊的注采开发模式,即水平井压裂后采用远端裂缝注水,近端裂缝采油.根据水平井压裂后的储层和压裂裂缝中油水两相渗流特征并考虑导流能力随时间变化,建立了压裂水平井“近采远注”开采模式下的油水产量预测数学模型,模型中将裂缝和油藏处理为同一渗流系统.应用有限差分法将数学模型离散化获得相应的数值模型,并选用IMPES方法求解,自行研制了相应的数值模拟器.研究表明:在一定生产时间段内,裂缝间距越小,日产油量越高,但最终累计产油量是随裂缝间距的增大而增大的,故应尽量增大裂缝间距施工；裂缝导流能力越高,日产油量和累计产油量越高,但裂缝产水量增加时间会提前,增加的幅度也会下降；优化了该油藏的人工裂缝长度和导流能力,应以增加裂缝导流能力为主获得较好的增产效果.
展开▼
