海上水平井同井不同压裂裂缝注采模拟

SIMULATIONS OF THE FRACTURE INJECTION AND PRODUCTION IN THE SAME OFFSHORE FRACTURED HORIZONTAL WELL

为高效开发海上低渗透油田,研究了水平井分段压裂后采用远端裂缝注水、近端裂缝采油的同井注采开发模式,建立了物理模型和数学模型。通过对模型的求解、生产动态预测软件的研制和模拟,分析了不同裂缝条数和裂缝导流能力下油井日产油量、累计产油量和含水率的变化。结果表明:随着采油裂缝条数的增加,油井初期日产油量增加、后期日产油量下降,油井含水上升越快、含水率越高;油井日产油量和累计产油量随着裂缝导流能力的增加而增加,但增加幅度会下降。针对给定的油藏参数,水平井分段压裂3条裂缝最好,裂缝导流能力在35μm^2·cm为佳。

In order to highly effectively develop offshore low-permeability oilfields, the mode of same-well injec- tion and production is researched and developed i.e. in a stage-fractured horizontal well, water injected into the far-end fractures and oil produced from the near-end fractures in the same fractured horizontal well. And moreover the physical and mathematical models are established. By means of solution-seeking of these model, software devel- oping to predict the production dynamics and the corresponding simulations, the changes of daily and cumulative oil productions and water cut are analyzed under the conditions of different numbers of fracture and fracture conductivi- ties. The study results show that with the rise of the number of oil-producing fracture, the initial daily oil produc- tion of oil wells will increase, but the corresponding late daily production will descend, and moreover the more rapid rise of the water cut, the higher water cut will be ; the oil production stated above increase with the enhance- ment of fracture conductivity, but the increased extent will decline. For the given reservoir parameters, in the stage-fractured horizontal well, three numbers of fracture will be the best choice and furthermore the preferred frac- ture conductivity is 35 um2 cm.