INVESTIGATION OF CRITICAL FACTORS AFFECTING PRESSURE DISTRIBUTION OF A HORIZONTAL WELL NEAR A SEALING OIL RESERVOIR EXTERNAL BOUNDARY

Abstract

Horizontal wells enhance reservoir contact and productivity, but display complex pressure behaviour due to reservoir boundary effects, well design, reservoir fluid and wellbore conditions. This paper investigates the factors affecting pressure distribution in a horizontal well located near a sealing boundary, with emphasis on the implications of well design and key reservoir parameters on well performance. The principle of superposition is utilized to compute dimensionless pressure and pressure derivatives of horizontal well near a sealing boundary. Object well distances from the sealing boundary, well skin and storage were considered. Reservoir anisotropy is not considered. Results show that critical factors affecting horizontal well performance are dimensionless wellbore radius, horizontal well length, wellbore skin and storage factor. Furthermore, two characteristic pressure gradients are observable: infinite-acting flow and boundary dominated regime with a slope of 2.3026 per cycle.