Study On Productivity Prediction And Inflow Performance Characteristics Of Slanted Well

In recent years, because of their unique advantages and features，slanted wells areincreasingly being used in oil and gas field development. For slanted wells, reasonableproductivity prediction is of great significance. It can provide exact basis for the selection ofoil production method and the optimization of production parameters.For slanted wells, this article respectively studied the productivity prediction methods ofsingle–phase steady flow and two-phase (gas/oil) flow, as well as the inflow performancecharacteristics of solution gas drive reservoir.Firstly, by establishing the3-D steady state flow model, a more accurate method tocalculate the pseudo skin factor of slanted wells had obtained. By compared the extantformulas of pseudo skin factor with the former result, we point out the using condition ofthese formulas.Secondly, based on Mass Conservation, Darcy Law, as well as Mass and MomentumConservation, oil-gas two phase three-dimensional percolation model in reservoir and pressuredrop model of two-phase (gas/oil) flow, which constituted the productive prediction model forsolution gas drive reservoir in slanted well bore, was established. Meanwhile using Drift-Fluxmodel, the hydrodynamic characteristic of two-phase flow in the wellbore is described. Bydiscretizing the coupling model, array of difference of the model and solution has beenobtained.Finally, for the solution gas drive reservoir, this article utilized multi-segment wellmodel in Eclipse reservoir simulation software, following Cheng’s way to study the inflowperformance characteristics, to study9kinds of slanted wells with different deviations. Aftersynthetically considering the reservoir fluid properties、the reservoir properties as well as thefeatures of wellbore,405different slanted well models were established. On the base of them, the factors which influenced inflow performance characteristics were analyzed. FollowingVogel’s dimensionless IPR curve method, this dissertation handled with IPR curves of all themodels, while a large quantity of nonlinear regression fittings were done by origin software.Then, a new dimensionless IPR curves relationship, which took formation heterogeneity intoconsideration, was given. The new formula, which is better than Cheng’s, can give a morequick and convenient way to predict the inflow performance of slanted wells.