Wygd Study on prediction method of drilling pressure in low permeability oilfield

Abstract

During the high water cut development stage of low permeability in M block, the overall recovery degree is low, there has 100 infilling wells been drilled since 2020 to improve the development effect. Before drilling, in order to avoid the risk of pressure safety, it is necessary to shut down the peripheral water injection wells to relieve the pressure, at the same time.Since the M Block reservoir is a low permeability reservoir, the pressure relief time after drilling off is long, which increases the impact on the production of developing wells and increases the fluid transportation and the related production costs, while there is no uniform standard for the time, pressure and distance of drilling off. In order to control the production loss of developing wells and save the shut-in cost. This paper applies numerical simulation and reservoir engineering method, by establishing fine geological model, optimizing simulation technology, considering the influence of start-up pressure gradient, establishing theoretical formula and mathematical model of drilling pressure, clarifying the law of drilling-off pressure relief and pressure drop, calculating the formation pressure of single well in the whole area, forming the drilling-off limit and rapid pressure prediction method, through comparison and verification, the overall deviation is 3.8%, and the method is accurate and reliable.