Data Mining Identifies Production Drivers in a Complex High-Temperature Gas Reservoir.

This paper presents the results of a data-driven; field-modeling (DDFM) evaluation applied to a high-temperature reservoir in Australia for the purpose of determining the significance of chemistry, reservoir, well, and hydraulic-fracture characteristics on well production. The DDFM approach has identified key production drivers for a gas-well field in Australia. This information has been useful in explaining hydraulic-fracture well production and providing guidelines for future fracture stimulation success. A DDFM process is used to develop a model for 32 wells completed in a complex, 250 to 350°F gas reservoir in Australia. This type modeling technique uses data from the field, including chemical formulation, geology, reservoir, well, completion, hydraulic-fracture stimulation, and production results. The data is integrated into a common format and resolution, and then a visual and statistical evaluation is performed. Relevant correlations and useful trends are noted. Next, an effort is made to develop a predictive model that can be used to provide an overall explanation as to what parameters drive production in the well field. Or, in effect, derive a high-level understanding about the effect of the fracturing process on the reservoir. This is accomplished by the use of data modeling/optimization technologies, including artificial neural network (ANN) and genetic algorithms. The resulting ANN model can then be used to evaluate the production associated with various hydraulic-fracturing scenarios and/or characteristics. Validation of conclusions and/or resolution of difficult interpretation issues are done by detailed evaluation and modeling of key wells. Hydraulic-fracture stimulation scenario evaluations performed by the ANN model have yielded some expected as well as unexpected results. As expected, reservoir characteristics, such as pay thickness, porosity, and water saturation have a dominant effect on well production. What was unexpected is the significance of well operations and stimulation fluid chemistry on well production. The practice of killing the well after stimulation and using inappropriate perforation techniques can reduce gas production by as much as one-half, while the use of a high-temperature gel breaker in combination with a reduction in base-gel polymer load can provide a 67% increase in production. [ABSTRACT FROM AUTHOR]