Abstract

Fracture diagnostic technologies are an important aspect of unconventional stimulation where operators need the knowledge to improve completion performance and reduce capital expenditure. Diagnostic measurements provide information before production results and enable a larger number of samples to support statistical comparison.

Pressure sensors provide cost-effective monitoring solutions which generate large volumes of data. Unfortunately, such data sets can be difficult to transform into actionable insight. Pressure monitoring can be done at many locations including the treatment well, offset parent well, nearby sealed wellbore, or an isolated stage from a nearby well. This paper focuses on combining the analysis of two pressure monitoring techniques: post-treatment pressure leak-off analysis and pressure-based fracture maps. Combining these two techniques provides near-field and far-field measurements. An estimated stimulated rock volume may be calculated by evaluating the fracture extent and connectivity along the wellbore. The average treatment parameters are compared for different combinations of fracture area and stimulation efficiency to highlight beneficial trends in completion designs.

Each technology is briefly reviewed along with how these two methods compliment the other. A Wolfcamp A study was conducted using an anonymized data set. This larger study incorporated work from multiple operators and projects; thus providing sufficient sampling and conclusions. The study demonstrated that cost-effective monitoring can be used to update completion designs and to maximize the stimulated rock volume.

Introduction

Shale exploration has grown tremendously in the past decade. Many technological advances have been introduced, tested, and evaluated to help operators modify the completion pumping schedule and maximize the effective stimulated rock. More production should result from better stimulated rock, however, there is an economic tradeoff between the cost of the stimulation treatment plan and the recoverable hydrocarbons. A few challenges with waiting for production results to define better stimulation include: the time delay of production, cost of stimulating an entire well, and not having enough comparable data points to draw statistically significant conclusions. Fracture diagnostic tools have been created to provide insight into stimulation performance before getting production data. Diagnostics can measure information at the stage or cluster level.

Pressure sensors have become an economical option to acquire large data sets for analytical applications. Several new analysis techniques can provide improved understanding of unconventional reservoir stimulation and production. Challenges arise as many operators acquire more pressure data without the proper knowledge of how to mine useful information to support completion and production decisions. There are two main hurdles: first, understanding how to get knowledge from a pressure data stream, and second, how to scale the results from a single well, or pad, and apply it to development acreage.

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