Packer-Induced Stresses During Hydraulic Well Fracturing

1981 ◽  
Vol 103 (4) ◽  
pp. 336-343 ◽  
Author(s):  
W. E. Warren
Keyword(s):  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Circular Cylindrical Shell ◽  
Elastic Solid ◽  
Gas Recovery ◽  
Linear Elastic ◽  
Analytical Approximations ◽  
Induced Stresses ◽  
The Difference

Well bore stresses induced by inflatable packers during hydraulic fracturing operations are investigated. The geologic formation is modeled as an unbounded homogeneous isotropic linear elastic solid containing an infinitely long circular cavity, while the packer is modeled as a semi-infinite thin-walled circular cylindrical shell. For given packer properties, these induced stresses are shown to depend on the difference between packer pressure and fracturing pressure and can become significant. Typical numerical results are obtained and presented graphically. Analytical approximations for the maximum values of these stresses are also presented. While these effects are of no importance in the usual application of hydraulic fracturing to enhance oil and gas recovery, they are crucial in attempts to estimate in-situ stresses from hydraulic fracturing pressure data.

scholarly journals Numerical Investigation of the Impacts of Borehole Breakouts on Breakdown Pressure

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 888 ◽  
Author(s):  
Hua Zhang ◽  
Shunde Yin ◽  
Bernt Aadnoy
Keyword(s):  
Hydraulic Fracturing ◽  
Shear Failure ◽  
In Situ Stress ◽  
Test Results ◽  
Breakdown Pressure ◽  
Borehole Breakout ◽  
Borehole Breakouts ◽  
The Difference ◽  
Mud Pressure

Borehole breakouts appear in drilling and production operations when rock subjected to in situ stress experiences shear failure. However, if a borehole breakout occurs, the boundary of the borehole is no longer circular and the stress distribution around it is different. So, the interpretation of the hydraulic fracturing test results based on the Kirsch solution may not be valid. Therefore, it is important to investigate the factors that may affect the correct interpretation of the breakdown pressure in a hydraulic fracturing test for a borehole that had breakouts. In this paper, two steps are taken to implement this investigation. First, sets of finite element modeling provide sets of data on borehole breakout measures. Second, for a given measure of borehole breakouts, according to the linear relation between the mud pressure and the stress on the borehole wall, the breakdown pressure considering the borehole breakouts is acquired by applying different mud pressure in the model. Results show the difference between the breakdown pressure of a circular borehole and that of borehole that had breakouts could be as large as 82% in some situations.

scholarly journals The Local Economic and Welfare Consequences of Hydraulic Fracturing

2019 ◽  
Vol 11 (4) ◽  
pp. 105-155 ◽  
Author(s):  
Alexander W. Bartik ◽  
Janet Currie ◽  
Michael Greenstone ◽  
Christopher R. Knittel
Keyword(s):  
Willingness To Pay ◽  
Hydraulic Fracturing ◽  
Equilibrium Model ◽  
Household Income ◽  
Oil And Gas ◽  
Economic Indicators ◽  
Spatial Equilibrium ◽  
Welfare Impacts ◽  
Gas Recovery ◽  
Spatial Equilibrium Model

Exploiting geological variation and timing in the initiation of hydraulic fracturing, we find that fracking leads to sharp increases in oil and gas recovery and improvements in a wide set of economic indicators. There is also evidence of deterioration in local amenities, which may include increases in crime, noise, and traffic and declines in health. Using a Rosen-Roback-style spatial equilibrium model to infer the net welfare impacts, we estimate that willingness-to-pay (WTP) for allowing fracking equals about $2,500 per household annually (4.9 percent of household income), although WTP is heterogeneous, ranging from more than $10,000 to roughly 0 across 10 shale regions.(JEL D12, K42, L71, Q35, Q51, Q53, R41)

The crack tip region in hydraulic fracturing

1994 ◽  
Vol 447 (1929) ◽  
pp. 39-48 ◽  
Keyword(s):  
Hydraulic Fracturing ◽  
Elastic Solid ◽  
Square Root ◽  
Power Law Fluid ◽  
Fracture Width ◽  
Linear Elastic ◽  
Finite Case ◽  
Strain Fracture ◽  
Square Root Singularity ◽  
Elastic Fracture

We present analytical tip region solutions for fracture width and pressure when a power law fluid drives a plane strain fracture in an impermeable linear elastic solid. Our main result is an intermediate asymptotic solution in which the tip region stress is dominated by a singularity which is particular to the hydraulic fracturing problem. Moreover this singularity is weaker than the inverse square root singularity of linear elastic fracture mechanics. We also show how the solution for a semi-infinite crack may be exploited to obtain a useful approximation for the finite case.

scholarly journals In situ transformation of hydraulic fracturing surfactants from well injection to produced water

2019 ◽  
Vol 21 (10) ◽  
pp. 1777-1786 ◽  
Author(s):  
Brandon C. McAdams ◽  
Kimberly E. Carter ◽  
Jens Blotevogel ◽  
Thomas Borch ◽  
J. Alexandra Hakala
Keyword(s):  
Environmental Impact ◽  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Produced Water ◽  
Unconventional Reservoirs ◽  
Oil And Gas Development ◽  
Hydrocarbon Recovery ◽  
Fracturing Fluids ◽  
Unconventional Oil And Gas

Chemical changes to hydraulic fracturing fluids within fractured unconventional reservoirs may affect hydrocarbon recovery and, in turn, the environmental impact of unconventional oil and gas development.

Laboratory-Scale-Model Testing of Well Stimulation by Use of Mechanical-Impulse Hydraulic Fracturing

SPE Journal ◽  
2015 ◽  
Vol 20 (03) ◽  
pp. 536-549 ◽  
Author(s):  
Luke P. Frash ◽  
Marte Gutierrez ◽  
Jesse Hampton
Keyword(s):  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Mechanical Energy ◽  
Scale Model ◽  
True Triaxial ◽  
Gas Recovery ◽  
Well Production ◽  
Well Injectivity ◽  
Stimulation Method ◽  
Mechanical Impulse

Summary Reservoir stimulation is commonly used to increase well-production rates and enable economic oil and gas recovery from conventional and unconventional reservoirs. One potential stimulation method that has been laboratory tested as a means to increase well injectivity after conventional hydraulic fracturing is mechanical-impulse hydraulic fracturing (MIHF). MIHF is a high-strain-rate stimulation method that uses a mechanical-energy source as an alternative to rapid gas expansion. Field-scale viability of MIHF was evaluated by use of elastic mechanics and thermodynamics. Results from laboratory tests are presented in which associated flow data indicated significant increases to well injectivity after MIHF stimulation. Tests were performed in two granite specimens with dimensions of 300×300×240 mm3 and 300×300×300 mm3, respectively. The first specimen was unconfined at room-temperature conditions, whereas the second was subjected to heating and true-triaxial confinement. Stimulated well injectivity was evaluated with a series of step-constant-pressure and step-constant-flow injection tests.

scholarly journals Gas-Wetting Alteration by Fluorochemicals and Its Application for Enhancing Gas Recovery in Gas-Condensate Reservoirs: A Review

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4591 ◽  
Author(s):  
Jiafeng Jin ◽  
Jinsheng Sun ◽  
Kesheng Rong ◽  
Kaihe Lv ◽  
Tuan A. H. Nguyen ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Current Knowledge ◽  
Gas Condensate ◽  
Dew Point ◽  
Wettability Alteration ◽  
Gas Reservoirs ◽  
Gas Recovery ◽  
Wellbore Pressure ◽  
Condensate Reservoir ◽  
The Difference

Gas-wetting alteration is a versatile and effective approach for alleviating liquid-blockage that occurs when the wellbore pressure of a gas-condensate reservoir drops below the dew point. Fluorochemicals are of growing interest in gas-wetting alteration because of their high density of fluorine groups and thermal stability, which can change the reservoir wettability into more favorable conditions for liquids. This review aims to integrate the overlapping research between the current knowledge in organic chemistry and enhanced oil and gas recovery. The difference between wettability alteration and gas-wetting alteration is illustrated, and the methods used to evaluate gas-wetting are summarized. Recent advances in the applications of fluorochemicals for gas-wetting alteration are highlighted. The mechanisms of self-assembling adsorption layers formed by fluorochemicals with different surface morphologies are also reviewed. The factors that affect the gas-wetting performance of fluorochemicals are summarized. Meanwhile, the impacts of gas-wetting alteration on the migration of fluids in the pore throat are elaborated. Furthermore, the Wenzel and Cassie-Baxter theories are often used to describe the wettability model, but they are limited in reflecting the wetting regime of the gas-wetting surface; therefore, a wettability model for gas-wetting is discussed. Considering the promising prospects of gas-wetting alteration, this study is expected to provide insights into the relevance of gas-wetting, surface morphology and fluorochemicals, further exploring the mechanism of flow efficiency improvement of fluids in unconventional oil and gas reservoirs.

Shale, Quakes, and High Stakes: Regulating Fracking-Induced Seismicity in Oklahoma, USA and Lancashire, UK

2019 ◽  
Vol 3 (1) ◽  
pp. 1-14
Author(s):  
Miriam R. Aczel ◽  
Karen E. Makuch
Keyword(s):  
United States ◽  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Seismic Activity ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
High Volume ◽  
The United States ◽  
Horizontal Drilling ◽  
Induced Seismic Activity

High-volume hydraulic fracturing combined with horizontal drilling has “revolutionized” the United States’ oil and gas industry by allowing extraction of previously inaccessible oil and gas trapped in shale rock [1]. Although the United States has extracted shale gas in different states for several decades, the United Kingdom is in the early stages of developing its domestic shale gas resources, in the hopes of replicating the United States’ commercial success with the technologies [2, 3]. However, the extraction of shale gas using hydraulic fracturing and horizontal drilling poses potential risks to the environment and natural resources, human health, and communities and local livelihoods. Risks include contamination of water resources, air pollution, and induced seismic activity near shale gas operation sites. This paper examines the regulation of potential induced seismic activity in Oklahoma, USA, and Lancashire, UK, and concludes with recommendations for strengthening these protections.

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