This project is to conduct a field-based hydraulic fracturing research program for horizontal shale wells with the objectives of reducing and minimizing potential environmental impacts, demonstrating safe and reliable operations, and improving the efficiency of hydraulic fracturing. The research will advance our understanding of the hydraulic fracturing process in shale reservoirs, and thus, enable the design and execution of effective fracture stages that significantly contribute to production. Improved design and execution of fracture stages will also reduce the number of future infill wells drilled, and reduce water volume and energy input. A smaller environment footprint associated with shale drilling will be the result of this work.
Gas Technology Institute, Des Plaines, IL, 60018
Despite the long history of hydraulic fracturing, the optimal number of fracturing stages during multi-stage fracture stimulation in horizontal wells is not known. In addition to the increased expense of multistage fracturing in horizontal wells, increasing the number of fracturing stages does not always correlate with an increase in production. The problem is the application of a uniform fracture stimulation design to all stages with no consideration for geological variations along the wellbore. The result is an inefficient use and costly waste of energy and water.
Optimization of the fracturing process requires an understanding of the cause-and-effect relationship between fracturing parameters and local geological properties at a given location along the wellbore. Realizing that the generalized rock mechanics theories and hypotheses are not truly applicable to fractured and laminated shales, quantifiable impacts of a shale’s geomechanical and depositional features are a prerequisite for design and implementation of optimized hydraulic fractures. The overarching goal of this project is to understand and define the relationships of shale geology and fracture dynamics using detailed field data that includes coring of the fracture domain. Analyses of the data will aid in updating fracture design models, and improve the effectiveness of individual hydraulic fracture stages.
In conventional fracture stimulation, a selected fracture design is implemented at all fracture stages of a horizontal well without consideration for reservoir heterogeneity or dynamic stress changes that occur during fracturing. As a result, 50 percent of the total production from the well will come from about one-third of the fracture stages pumped. The intended fracturing optimization through the HFTS program aims to eliminate this inefficiency by creating effective fractures at every stage. The net effect of such efficiency improvement will increase production from the well with no increase in the amount of water, chemicals, proppants, and energy required. This translates to minimized air emissions and other environmental impacts associated with production of a unit volume of oil and gas.
Laredo Petroleum offered a field site for the project in August 2015. The Laredo site includes 11 horizontal wells (10,000’ horizontal legs) drilled through the Upper and Middle Wolfcamp formation in the Permian Basin. In addition, Laredo has vertical wells nearby which are being used as observation wells. Significant events and field activities completed to date include:
The following data will continue to be collected: production, bottomhole pressure and temperature in producing and core wells, and produced fluid samples for oil and water tracer detection.Core description results (fracture and proppant distribution) are being used to supplement, validate, and calibrate fracture modeling efforts. Data analysis and integration continues. Plans are being developed to slab the core and collect samples that will be distributed to the eNational Labs for ongoing DOE research. The microbial analysis and water analysis will be completed in the next six months.
NETL-Backed Field Testing Project Seeks to Improve Efficiency and Safety of Hydraulic Fracturing (Dec 2017)
With a long record of success advancing hydraulic fracturing innovations, NETL teamed with Gas Technology Institute (GTI) of Des Plaines, Ill., to develop and execute a hydraulic fracturing test site program to answer questions, advance the understanding of the hydraulic fracturing processes to attain greater efficiencies, and improve environmental impacts.
Hydraulic Fracturing Test Sites (Aug 2017)
Presented by Jordan Ciezobka, Gas Technology Institute, 2017 Carbon Storage and Oil and Natural Gas Technologies Review Meeting, Pittsburgh, PA
Hydraulic Fracturing Test Sites (Aug 2016)
Presented by Jordan Ciezobka, Institute of Gas Technology, 2016 Carbon Storage and Oil and Natural Gas Technologies Review Meeting, Pittsburgh, PA