Pressure Transient and Production Data Analysis for Hydraulic Fracture Treatment Evaluation

Abstract

TX 75083-3836 U.S.A., fax 01-972-952-9435. AbstractThe Unified Fracture Design (UFD) concept provides a mechanism to determine the optimal hydraulic fracture design for a given amount of a selected proppant, while modern hydraulic fracture treatment execution offers the potential to achieve the optimal design. The proppant number is a ratio of the proppant permeability and proppant volume product to the formation permeability and reservoir volume product. The cost of the hydraulic fracture treatment is directly related to quality and quantity of proppant injected, and successful achievement of the optimal fracture treatment easily offsets this cost when appropriate economics is considered in the job design. Pressure transient and production data analysis are described in terms of fracture length and conductivity and do not provide measures of UFD parameters. The subject of this paper is the use of post treatment analysis to evaluate the effectiveness of the treatment in terms of dimensionless productivity index, dimensionless fracture conductivity, and the proppant number.Results of this analysis show that when conventional buildup tests cannot provide the desired post-treatment analysis, in most cases, production data analysis can, and vice versa. The analysis will address both single phase oil and gas primary production and oil production under pressure maintenance or waterflood. Also, non-ideal fractures with height growth beyond the producing formation thickness and fracture skin will be considered. Field examples will illustrate the analysis. The importance of this analysis is paramount for operators trying to optimize high value hydraulic fracture treatments.