The accuracy of the production forecast of fractured horizontal well not only affects the result of the optimum design and economic evaluation, but also affects the success and effectiveness of the fractured horizontal well. Therefore, it is quite essential to present new models fit for the actual seepage phenomenon to calculate the fractured horizontal well production. Multi-fractures propped when the horizontal well is fractured. But due to the stress difference along the horizon well and the restriction of the fracturing technology, the formed factures are different in length, conductivity, azimuth angle and so on. Moreover, during the production process, the fractures mutual disturbance makes the prediction of fractured horizontal well become more difficult, This paper combines the shape of formed fractures and the fluid peculation mechanism together to present a new model, which is based on superposition theory to predict the fractured horizontal well production The new model considers the effect of the fracture number, fracture length, fracture interval, the symmetry of the fractures, azimuth angle and conductivity We applied the new model to predict the productions of three fractured horizontal wells in China; the accordance is very well, up to 97.4%.
Horizontal well can greatly increase the contact area of the well bore and the pay zone, so it is an important means to exploit the low permeability oil reservoir and to enhance the production and ultimate recovery. Sometimes due to the low permeability, large seepage resistance, low connectivity in the low permeability reservoir, the production of the horizontal well is still low. Therefore, it is necessary to frac the horizontal well to enhance the production.
The accuracy of the fractured horizontal well production not only affects the result of the optimization design and economic evaluation, but also affects the success and effectiveness of the fractured horizontal wells, so it is vital to calculate the production exactly. According to related literature home and aboard, we found that it is a difficult problem to predict fractured horizontal well production. Soliman[1] et al researched the production model for the horizontal well with finite conductivity fracture in an infinite thick oil reservoir, and drawed the conclusion that larger conductivity can overcome the additional pressure drop caused by the linear influx flow. Li [2] et al presented a stable production model for the fractured wells. When the fracture plane is perpendicular to the well bore, he separated the n fractures into N flowing areas, and the each fracture is the center of the every area, supposing that each fracture produced only in its own area, this method didn't consider the fracture disturbance. B.Guo's [3] model is still fit for the stationary state flow, in this method, it should first to calculate one single fracture production, and then multiply single fracture production with N to get the N fractures production. Clearly, this method still didn't consider the fractures disturbance. Guo Jianchun[4] et al based on the fracture-reservoir system two dimension oil-water two phases model to simulate the production of horizontal wells, and combine the economic evaluation to presented an fractures optimum model for the fractured horizontal well.
