Comprehensive Fracturing Evaluation of the First Mauddud Formation Injector in South & East Kuwait

Abstract Mauddud is a cretaceous, thin and tight carbonate reservoir in South and East Kuwait. This reservoir produces through solution gas drive mechanism which is leading to a rapid reservoir pressure depletion with a recovery factor below 5%. Part of the development plan is to support the pressure through water injection, starting with pilot injectors. This paper covers the evaluation and stimulation workflow, as well as findings for the first pilot injector in this complex environment. Run diagnostics measurements such as spinner, temperature, pressure, sonic before the stimulation to understand the initial injectivity index and establish baseline for the zone of interest as well as the adjacent zones directly above and below it. After that, conduct a minifrac to measure key properties such as the treatment fluid leak-off and the fracturing pressure to calibrate the geomechanical model and hydraulic fracture design. Post the main stimulation treatment, the diagnostics measurements were utilized to analyze the injectivity index and the hydraulic fracture height. Before the treatment, the injection rate was below 50 bbl/d which was increased to 1250 bbl/d following the evaluation of the stimulation workflow. Temperature and sonic data confirmed the spinner observation showing almost no injectivity before the stimulation treatment. The low fluid leak-off observed in the minifrac further confirmed the extreme tightness of the rock leading to real-time stimulation re-design. The injectivity was enhanced from 0.02 to 0.6 bbl/day/psi post stimulation based on the diagnostics measurements while controlling the fracture growth and geometry to be within the zone of interest. This was a key objective to conclude the success of the workflow and the treatment on this critical pilot to further develop the injectors plan in Mauddud reservoir. This paper adds to the literature unique case study where simple, yet powerful integrated workflow is presented in detail to provide the oil industry with a valuable reference for reservoir management in tight environment.