Completion Optimization in the Williston Basin Through Integrated Data Sets

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 170721, “Completion Optimization and Validation in the Williston Basin Through Integrated Data Sets,” by J. Barhaug, SPE, V. King, SPE, A. Schmidt, SPE, A. Southcott, SPE, L. Steinke, SPE, and H. Harper, WPX Energy, prepared for the 2014 SPE Annual Technical Conference and Exhibition, Amsterdam, 27–29 October. The paper has not been peer reviewed. With the surge in activity in the Williston basin, the ability to optimize completions has mainly been an expensive trial-and-error system. With the advent of sliding-sleeve technology, operational efficiency could potentially be increased, but the effectiveness of the completion remained unclear. This paper presents a work flow to analyze data sets to optimize completion efficiency. Introduction The operator gathered a number of data sets from the Williston basin (the geology is discussed in the complete paper) and integrated the results to arrive at an optimized completion design at a fraction of the cost. This step was conducted with Phase 1; Phase 2 was then implemented to test the recommended design. This summary will focus on Phase 1, with detailed coverage of Phase 2 available in the complete paper. Completion optimization was defined as improving well performance and fracture behavior while also increasing internal rate of return. For Phase 1, there were four laterals with varying completion and isolation types and an S-shaped well used to acquire specialty logs, core data, and microseismic data. All of the completed stages used a hybrid fluid system with linear guar gel for the pad and 100-mesh sand stages (10,000 lbm pumped in single stages, 20,000 lbm in double stages) and then transitioned to a crosslinked guar gel for the 20/40-sand and 20/40-intermediate-strength-proppant (ISP) stages. A mix of 35% 20/40 sand and 65% 20/40 ISP was used on all the stages. The two-entry-point double-cemented stage was the current completion design at the time this study was conducted. This meant a total of 16 stages, with 31 entry points for a 9,500-ft effective lateral. The process undertaken to optimize the completion design in Phase 1 had several steps: Empirical comparison of interpreted fracture behavior in test wells using analysis of microseismic data, proppant-tracer data, and fracture-pressure history matching (FPHM) Determination from those analyses of preferred design components Constraint of additional design components by use of multivariate statistical analysis Filling out remaining design components by use of forward fracture modeling Estimation of the economic impact of the new design The components incorporated into the final design were isolation and entry-point type, perforation scheme, stage length, proppant volume, and treatment rate. The complete paper describes in detail the data sets that contributed to the final optimized completion design (miscroseismic, hydraulic-fracture model, multivariate analysis, and proppant tracer).