Experimental and Numerical Approach for the Productivity Study of Open Hole Completed Horizontal Wells

摘要

Formation damage in horizontal wells, often openrnhole completed, is a critical point for oil fields developedrnin deep offshore where acceptable development costs arernbased upon a limited number of highly productive wells.rnThis paper describes a simplified numerical approach tornmodel filter cakes removal by natural cleanup when thernwell is put under a drawdown pressure difference. A flowrnsimulator taking into account the near well permeabilityrnvariation has been developed using cylindrical grid withrnvery small gridblocks around the well. Laboratory datarnobtained on sandstones damaged with an oil-based mudrnhave been used as input data to model filter cakesrnremoval by natural cleanup. The purpose of thisrnmodelling is to optimize the applied drawdown pressurernto study the variation of well productivities as a functionrnof the pressure drawdown to get the best possible wellrnperformance preventing sand production problems inrnpoorly consolidated formations.