Stimex: an expert system approach to well stimulation design

Well stimulation plays a major role in enhancing oil and gas flow rate and recovery. Most oil and gas wells drilled and completed will eventually require an acidizing treatment or a fracturing treatment to improve oil and gas production. The design of a well stimulation treatment is a complicated process and requires in-depth knowledge of acidizing and fracturing theory plus practical experience. The objective of my research has been to develop an expert system to aid the stimulation treatment design engineer by providing sound logic, rules, and expert advice. A hybrid system called STIMEX has been developed in an object-oriented environment. STIMEX has integrated several rule-based knowledge systems, databases, and numerical simulators. STIMEX can be used to help an engineer design optimum well stimulation treatments. STIMEX also provides a complete explanation facility and a friendly user interface system. Using the expert system, a stimulation treatment can be designed to optimize well stimulation treatments. The expert system STIMEX will provide both (1) recommendations about a specific well stimulation treatment, and (2) an optimum treatment design, including optimal treatment type, optimal design models, optimal treatment fluids, optimal additives, optimal proppant, the optimal pumping technique, and the optimum treatment size. The system has been programmed using the experience and logic compiled from a group experts. We have successfully applied STIMEX using field applications. The expert system will be useful to practicing engineers in charge of well stimulation design and engineers who need to evaluate the success of prior stimulation treatments.