Formation damage due to fines migration and its remedial methods

Abstract

Well productivity decline have been widely observed for gas wells producing the reservoir fines. The phenomenon has been explained by the lifting, migration and subsequent plugging of the pores by the fine particles, finally resulting in permeability decrease. It has been observed in numerous core flood tests and field cases.This paper is based on a study and evaluation of a gas field in the North-western margin of the Nile Delta. It is a super gas field with current production capability of 0.8Bcf/d. It has the potential to produce above this level with the current stock of wells but have only been limited to this through-put due to considerable losses in well productivity that the wells have experienced in recent years due to fines migration phenomenon.Well testing analysis and well performance analysis were done to detect formation damage and provide an overall measure of formation damage. Laboratory core flood tests had been used to determine the causes, degree, and extent of damage. Scanning electron microscopy (SEM) was used to analyze the rock samples used for the core flood test before and after the test. Core flood test had been done to evaluate the effect of acid on improving and curing damaged cores. Matrix acid stimulation on a case study from the studied field was evaluated.