Print Email Facebook Twitter A semianalytic model for the productivity testing of multiple wells Title A semianalytic model for the productivity testing of multiple wells Author Fokker, P.A. Verga, F. TNO Bouw en Ondergrond Publication year 2008 Abstract We present a semianalytic method for modeling the productivity testing of vertical, horizontal, slanted, or multilateral wells. The method is applicable to both oil and gas reservoirs and automatically accounts for well interference. The use of analytic expressions ensures that short-time transient behavior and long-time semisteady-state behavior are handled appropriately, whether close to the well or further into the reservoir. Calculation times are still very limited - on the order of a few minutes to a few seconds when all wells are vertical. This makes the tool suitable for evaluating well testing and determining well productivity. We based the approach on an earlier derived productivity prediction tool, in which the steady-state equations were solved. It has now been extended to solve the time-dependent diffusion equation. In our current method, the equations have first been transformed using the Laplace transformation. The expressions for the producing wells are combined with auxiliary sources outside the reservoir. The crux of the semianalytic method involves an adjustment of the positions and strengths of these sources in order to approximate the boundary conditions at the reservoir boundaries. The solution obtained is transformed back into the time domain by use of a Stehfest algorithm. The new approach has been validated with numeric tools, including both reservoir simulators and well-test interpretation software. Validations were performed with artificial cases and with field production data, using both single-well and multiple-well production tests. The results of these tests were excellent. Copyright © 2008 Society of Petroleum Engineers. Subject Geological Survey NetherlandsGeosciencesEnergy / Geological Survey NetherlandsBoundary conditionsDifferential equationsEquations of stateHorizontal wellsOil wellsPetroleum reservoir engineeringProductivityInterpretation softwareOil and gas reservoirsReservoir simulatorsWell interferenceboundary conditionhydrocarbon reservoirOil productionReservoir characterization To reference this document use: http://resolver.tudelft.nl/uuid:7eecc2a7-4674-4b2a-b73a-275d636a371c TNO identifier 280042 ISSN 1094-6470 Source SPE Reservoir Evaluation and Engineering, 11 (3), 466-477 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.