Horizontal Well's Production Design And Development Index Forecast Method

Horizontal well is a very important technology to explore oil field and to enhance recovery factor. Horizontal well can increase the contact area in the pay zone and improve developmental effect of pay zone and arise very big attention in the word. Horizontal well is supervior to vertical well especially in low permeability reservoir, thin pay zone, viscous oil, residual oil and so on. Horizontal well have greatly reduced and it is very spread to explore oil field with horizontal well. Horizontal well's production is reasonabely designed and development index is accurately forecasted, and this has become an important problem to reach the development effect of oil field's forecast. According to the geological instance of Nanyi reservoir in this artical, it systemically research the method of horizontal well, development index forecast, and economical evaluation. Research result indicate that the mathematical model of horizontal well's production forecast can accurately forecast the horizontal well's production and it is established by mirror image theory and potential stack theory and its forecast result is close to fact. This article research the effect factor of horizontal well's production from oil well's characteristic, reservoir's style and pay zone's damage instance. And in the common , the research result indicate that pay zone's damage instance is principle factor, but anisotropy permeability ratio can not be neglected, especially when horizontal length is very small and extortionate anisotropy permeability can improve the horizontal well's production. With the increasing of horizontal well's length, it can decrease other effect factors in some extent, such as high anisotropy permeability ratio, high skin factor, and horizontal well's decentralize distance. This article offer a kind of method to forecast the horizontal well's production and economically evaluate the development effect of horizontal well. Comparing with the vertical well, the result indicates that the horizontal well's development effect is superior to that of five vertical wells. In the same time, the recovery percent of reserves of a horizontal well is 1.5 times to that of five vertical wells. During the forecast ten years, horizontal well's production is higher than that of five vertical wells. It is obvious that horizontal well's development effect is superior to vertical well.