Knowledge Base
Technical Papers and Articles
Article

Innovative Pressure Map Offers Insights on Frac Hits

Trent Jacobs, JPT Digital Editor
August 7, 2018

In less than 3 years after starting up, Reveal Energy Services’ first-to-market technique for interpreting offset-well pressure data has been used to monitor more than 5,000 fracturing stages.

Its chief deliverable is a pressure-based map of a well’s hydraulic fracture geometry—the length, height, asymmetry, and direction of the manmade hydrocarbon-conduits. These maps help producers understand how effective their completion designs are at stimulating tight-rock reservoirs, but the data used to make them has led Reveal to some deeper insights.

One of them may amount to an assessment of frac hit severity, which would give operators a clearer idea of whether new fractures directly impacted an offset well, or if the interference was due to more benign mechanisms such as a pressure front moving through the rocks.

Article

URTeC: 2886118 – Estimation of Fracture Geometries From Poroelastic Pressure Responses in Offset Wells

Abstract

We present a general method for estimating fracture geometries from offset pressure signals that is scalable to large, complex, multi-well pad operations. The method leverages validated theory and implementation from the domain of mathematical optimization to efficiently and effectively compute macro-scale fracture dimensions for many realizations, based on randomized initial conditions. These realizations establish uncertainty bounds for a global solution, which is determined by way of fine-scale refinement of a candidate solution drawn from the macro-scale results.

Article

URTeC: 2902114 – Rapid Evaluation of Diverter Effectiveness From Poroelastic Pressure Response in Offset Wells

Unconventional Resources Technology Conference, July 23-25, 2018
Houston, Texas

Abstract

The ability to determine diverter effectiveness quickly, cost effectively, as well as being operationally noninvasive has been troublesome for the industry. However, a unique approach that represents a significant change in evaluating diversion effectiveness has been developed using offset pressure measurements, enabling a process to help design a completion strategy to fully stimulate each stage, enhance cluster efficiency, and improve fluid distribution across the stage. The knowledge of diverter effectiveness provided by this approach shall lead to a better understanding of the diversion process and enable real-time optimization, where the results of a diverter stage are used to adjust treatment design for subsequent stages. These diagnostic measurements shall augment and enhance other diagnostic methods curr…

Article

Operating Under Pressure

Oilfield Technology, May 2018

Early in 2015, a Statoil R&D team decided to confront a decades-old challenge. Even though the industry had been fracking wells for nearly seven decades, understanding and mapping of fracture growth remained elusive, often preventing informed decisions about full-field development. The reason was simple: The existing fracture map technology could only be applied to a limited number of wells because the cost was prohibitive.

The team went to work knowing a digital transformation could address the cost issue that would, in turn, address the full-field necessity for a comprehensive insight into fracture growth and the mapping of the fracture network. If successful, the team would be able to offer the industry greater awareness into why all of this is vital in the first place: the issue of geologic variability that can cause wells even very close to produce vastly different amounts of oil.

The R&D work proceeded swiftly. By the second half of 2015, the team began internal validation studies of what was called an integrated modeling approach for geometric evaluation of fractures or IMAGE Frac™ technology. The technology is based on a pressure gauge on a monitor well to record the poroelastic pressure response from a nearby treatment well that was hydraulically fractured. The purpose, and the foundation of the new approach, was to create a pressure-based fracture map, an industry first.

Early in 2016, the team began what turned out to be successful pilot projects. Following this external technology validation, the venture capital group, Statoil Technology Invest, created a spin-out entity, Reveal Energy Services, in late 2016, with IMAGE Frac technology as the foundation of the company. This oilfield services company startup has an exclusive license to the pressure-based fracture map technology and the essential patents.

In addition to offering 3D fracture map of half-length, height, asymmetry, and azimuth, the pressure-based fracture map data support four other applications that allow operators to

  • -determine how far proppant has been placed within the fracture
  • -understand whether a diversion design is working
  • -know if fluid is distributed equally between multiple clusters
  • -identify the depletion boundary surrounding a parent well.
Article

Improving Efficiency With Near Real-time Diversion Design Evaluation

Hart’s E&P, March 2018

If there is a word that describes the U.S. energy industry, “resiliency”—the ability to spring back or rebound quickly—certainly comes to mind. Since early 2016 at one of the industry’s lowest points to today’s footprint, oil and gas professionals have figured out how to do more with less.

The industry’s never-give-up mindset that is shifting the country from a net energy importer to a net energy exporter by 2026 or earlier, according to the U.S. Energy Information Administration, is writing a new chapter in the industry’s history. This mindset is directed at producing a greater percentage of hydrocarbon using new methods that decrease geologic and financial risks in the greater efficiency scenario throughout the major U.S. shale plays.

As part of this scenario, a new, faster method of diversion design evaluation has been commercialized. DiverterSCAN technology offers near real-time evaluation to ensure hydraulic fracturing fluid stimulates multiple perforation clusters. LINN Energy, working in the Scoop/Stack, received the first near real-time results, increasing hydraulic fracturing efficiency.

Article

New Technology Offers Completions Quality Control

Shale Technology Showcase, Hart’s E&P, July 2017

IMAGE Frac technology analyzes the recorded pressure data and determines the fracture attributes, including length, height, fracture growth rates and fracture asymmetry.

New Age Fracture Mapping Diagnostic Tools-A STACK Case Study

SPE Hydraulic Fracturing Technology Conference and Exhibition, 24–26 January, The Woodlands, Texas, USA

Abstract

SPE Hydraulic Fracturing Technology Conference and Exhibition, 24–26 January, The Woodlands, Texas, USA Abstract The application of learnings from an underground laboratory has led to significant completion changes in a world-class North American unconventional asset. Understanding the stimulated fracture geometry in unconventional reservoirs allows for optimal development of the asset. In this paper, we will review a case study comparing both new and commonly accepted technologies to quantify stimulated fracture geometry. The technologies applied to improve the understanding of fracture geometry in this case study include fiber optic monitoring (Distributed Acoustic Sensing and Distributed Temperature Sensing), borehole microseismic, electromagnetic imaging, offset well pressure monitoring with IMAGE Frac technology, water hammer analysis, and fracture modeling. The validation tools used include a production interference test, Rate Transient Analysis (RTA), Oil Soluble Tracers (OST), and Fracture Fluid Identifiers (FFI). Fiber optic monitoring was used to assess cluster efficiency, fluid and sand distribution per cluster and diverter effectiveness. Hydraulic half-lengths, heights, and fracture azimuth were estimated using a borehole microseismic system consisting of three vertical arrays and two horizontal arrays. Electromagnetic imaging provided insight on hydraulic half-length for 12 stages. Offset pressure monitoring provided hydraulic and propped half-lengths, heights, and fracture azimuth. The fracture model was calibrated using a diagnostic fracture injection test and vertical logs from the section of interest. Results from the technologies suggest an increase in well density is required to maximize the project net present value. The offset well pressure data coupled with fiber optic monitoring led to optimization of diverter applications. A variety of completion variables were tested, including fluid design, proppant size, perforation designs and diverter types, results have been integrated into an improved completion design.

Technical paper

Breakthrough in Hydraulic Fracture & Proppant Mapping: Achieving Increased Precision with Lower Cost

Unconventional Resources Technology Conference, August 1-3, 2016

San Antonio, Texas

Abstract

Hydraulic fracturing has been instrumental in commercializing ultra-tight unconventional resources. Although hydraulic fracturing has been used for nearly half a century in more than a million wells, understanding and mapping hydraulic fracture growth remains a challenge for shales and ultra-tight reservoirs. A number of approaches have been taken to better understand and characterize hydraulic fractures in the subsurface, but a technology which can accurately map hydraulic fractures with minimal operational interference and negligible cost remains elusive. Microseismic based mapping is arguably the most ubiquitously deployed method, but this approach is costly and provides limited insight into characterizing hydraulic fractures. Alternative technologies for mapping hydraulic fractures are currently being explored, but many of these technologies provide only qualitative information or require expensive data acquisition tools. This paper discusses a novel hydraulic fracture and proppant mapping technology (IMAGE Frac), which is technically robust, easy to use, and low cost. The technology is founded upon basic poromechanic theory, utilizing measurements from surface pressure gauges during the stimulation process to determine the geometry, orientation, and spatial location of hydraulic fractures with higher precision than other traditional techniques, while providing insight into the proppant distribution. The data acquisition approach requires only minor deviations from traditional practices and can be implemented without impacting completions efficiency. This technology has been utilized successfully in over 30 wells in multiple plays including the Bakken and Eagle Ford and is targeted for deployment in several other plays in mid-2016. An overview of the technology is provided along with an in-depth discussion of the validation studies from both the field and simulations. Two case studies are provided, which show the potential of the technology to provide new insight and improve drilling and completions operations. The case studies illustrate specific examples of how this technology enables better selection of landing zones, proppant size, pumped volumes, well spacing, and overall completions strategy. A companion paper (Kampfer and Dawson, 2016) discusses the fundamentals of the technology and provides in-depth, simulation-based studies, which demonstrate the robustness of the technique.

Technical paper

A Novel Approach to Mapping Hydraulic Fractures Using Poromechanic Principles

US Rock Mechanics / Geomechanics Symposium

June 26-29, 2016

Houston, Texas

Article

New Diagnostics Aid Completion Designs

Joel Parshall, JPT Features Editor, Society of Petroleum Engineers

November 30, 2016