Innovative Technique to Prevent Post-Fracturing Water Production using Relative Permeability Modifiers

Abstract

Abstract Hydraulic fracturing has been used for a long time in the Egyptian western-desert reservoirs and has proven to be very beneficial in increasing well productivity by approximately 25% over that of wells completed without hydraulic fracturing. However, production of water caused by fracture growth into the adjacent underlying (or overlying) water zones to the hydrocarbon zone is a major challenge. Excessive water production threatens the economics of a well by Shortening its production life by trapping the hydrocarbon reservesIncreasing disposal and lifting costs that can reach up to an estimate of billions of dollars, partially attributed to water-disposal regulationsBoosting fines-migration problemsIncreasing the rate of tubular corrosion and scale buildup These can be sufficient reasons to not consider fracturing in marginal fields. The conformance-while-fracturing (CWF) technique incorporates a relative permeability modifier (RPM) in the fracturing-fluids design. The RPM provides a reduction in effective permeability to water without significant changes to the relative permeability to oil. Applying the CWF technique resulted in water cut as low as 4%, even when the adjacent water zones were within 10 ft of the perforations. This technique provides a tremendous economic boost and has been found to be an effective solution for fields otherwise plagued with water production. Increased recoverable reserves are now being observed from these wells. This paper discusses the geological and reservoir parameters of the wells and zones of interest, the properties of the RPM, the CWF job-design considerations (and the associated challenges to the job design), its field applications, and post-fracturing results in comparison to offset wells fractured conventionally in the same reservoir and at the same level. It is envisaged that CWF techniques will prove to be beneficial to other operators facing similar production challenges.