Abdoljalil Varavei

Water Management in Mature Oil Fields using Preformed Particle Gels

Excess water production is a major problem that leads to early well abandonment and unrecoverable hydrocarbon in mature oil fields. Gel treatments at the injection wells to preferentially plug the thief zones are cost-effective methods to improve sweep efficiency in reservoirs and reduce excess water production during hydrocarbon recovery. A recent gel process uses the preformed particle gels (PPGs) to overcome distinct drawbacks inherent in in-situ gelation systems, i.e. lack of control on gelation time, uncertain gelling due to shear degradation, chromatographic fractionation or change of gel compositions, and dilution by formation water. This paper describes the results of PPG injection in both fracture and sandpack models where the experimental results were used to develop and validate mechanistic models to design and optimize the flowing gel injection for conformance control processes. Crucial properties gel such as in-situ rheology and swelling ratio in addition to oil recoveries were investigated. The water and oil permeability reduction factors were measured and modeled as a function of gel strength, rock permeability, and flow rate. The PPG transport models were successfully implemented in a reservoir simulator and validated against the laboratory experiments.

Optimization of Shale Gas Production Using Design of Experiment and Response Surface Methodology

High cost and uncertainty are among the most pre-eminent factors to be considered in shale gas production. Many parameters significantly affect production from such reservoirs. In this work, a new approach is proposed to obtain the optimal gas production scenario by optimizing the uncertain factors. Design of Experiment is used to analyze the order of influence of these factors, and then employ Response Surface Methodology to optimize the significant factors with economic analysis to obtain the most economical production scenario. Results show that this approach is effective and efficient for hydraulic fracturing treatment design and production scheme optimization.