Completion Optimization Through Advanced Stimulation Technology and Reservoir Analysis: A Case Study in the Red Fork Formation, Okeene Field, Major County, Oklahoma
Authors: Harkrider J.D. , Middlebrook M.L. , Huffman C.H. , Aud W.W. , Teer G.A. , Hansen J.T. 
Published: December 2007

Completion Optimization Through Advanced Stimulation Technology and Reservoir Analysis: A Case Study in the Red Fork Formation, Okeene Field, Major County, Oklahoma J.D. Harkrider, SPE, M.L. Middlebrook, SPE, C.H. Huffman, SPE, W.W. Aud, SPE, Integrated Petroleum Technologies, Inc.; G.A. Teer, SPE, Lomak Petroleum, Inc.; and J.T. Hansen, SPE, Gas Research Institute

This paper illustrates the use of advanced stimulation technologies coupled with reservoir analysis to improve gas production from a low permeability formation. Modern stimulation techniques used include real-time treatment data analysis, stress profiling, three dimensional fracture modeling and fluid quality control procedures. Implementation of these technologies was based on an evaluation of previous and current completion and stimulation approaches in the study area. A statistical review was performed to characterize the reservoir and establish a baseline from which to compare results and quantify benefits of the completion optimization process.

Part of the project was performed under the Gas Research Institute Advanced Stimulation Technology Deployment Program. Through the use of modern completion and stimulation practices, the operator was able to nearly double the average initial production rate in the Red Fork formation from 300 Mscf/d to over 600 Mscf/d. Ten year reserve estimates have increased about 38% from 390 MMscf to over 540 MMscf. Acceleration of reserves has allowed the operator to produce in less than 5 years the same amount of gas that was previously recovered in 13 years. The combination of improved reserve recovery and accelerated production has increased the discounted cashflow about 43%.

Introduction

This project, from the beginning to the end, attempted to integrate the complete package of engineering practices to optimize costs and results. A multi-phase program was outlined and included an initial phase of evaluating previous completion and stimulation approaches in the area. The following technologies and techniques were implemented in baselining previous results:–Integration of practical and theoretical considerations to evaluate prior completions.–Advanced 3-D fracture modeling of breakdown and fracture treatment pressure responses.–Reservoir simulation of production and pressure responses.–Iteration between fracture treatment and production response on all wells to achieve consistency of overall interpretation.–Establishment of a production response baseline from offset well history.

Once the baseline analysis was completed, field deployment was implemented and included a continued evaluation and evolution of approaches. This phase employed the following technologies and techniques:–Intense surface and in-situ fluid and equipment quality control before and during each fracture treatment.–Advanced real-time evaluation of the treating pressure response on all treatments.–On-site, real-time integration of fluid and equipment quality control with pre-treatment diagnostics and main fracture treatment execution.–Pre-treatment diagnostics to identify closure pressure of the Red Fork and adjacent layers, observe the leakoff response of various fluids and determine the quality and complexity of the near-wellbore and far-field fracture geometry.–Real-time execution of fracture treatments to optimize near-wellbore and far-field proppant placement/conductivity.–A coupled approach to acquire both post-treatment pressure decline data, which yields a better understanding of the fracture treatment, and rapid flowback to enhance fracture conductivity and minimize formation damage.

The final phase of the project was a cost benefit analysis. This comparative analysis of wells using modern completion practices to the offset production baseline quantified the benefits of optimization. The following were used in this phase of the project:–Comparison of long-term production response on new wells to previous wells.

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