Application of Volatile Solvent Treatment for Downhole Water Blockage and Organic Residue Removals – A Case Study

Abstract

Abstract Liquid blockage is a damage mechanism which occurs due to accumulation of immovable liquid phase near the wellbore area causing impairment of the relative permeability of the valuable hydrocarbons leading to significant reduction in production. The liquid block may be caused by the accumulation of condensates, water or immovable emulsions formed by interaction of incompatible fluids. These incompatible fluids may be introduced during the drilling operations or during the commingled production of fluids through single completion string. This damage may cause complete seizure of production in low pressure gas wells due to drastic reduction in the relative permeability of gas due to high mobility contrast. Similarly, the potential organic residue deposition in injection wells cause significant damage leading to abnormal injection pressures and rendering the operation expensive and uneconomical. A well-known solution for treating liquid blocks is the usage of alcohol-based treatments that work by reducing the viscous forces of the blocking fluid, reducing the interfacial tension, solubilizing the blocking water, causing vaporization, and subsequently removing the fluid blockage. Similarly, the aromatic fluids-based mixture with mutual solvent has been used for treatment of organic residue depositions and emulsion removal. However, limited applications of these solutions in the Indus Basin require further work on the subject to establish the minimum confidence on the successful solution recipe and development of the best practices for such wells. This paper demonstrates the practical application of utilization of these solutions for successful treatment of liquid blockage in 1st attempt, putting depleted gas well back at pre water block damage production level and significant improvement in injection pressures of another injector well saving multi folds cost of operation.