Hydraulic fracture propagation in high porosity media

2020 ◽  
Author(s):  
Aliya Tairova ◽  
Georgy Belyakov ◽  
Nikita Iudochkin ◽  
Aleksandr Molokoedov
Keyword(s):  
Oil Reservoir ◽  
Round Hole ◽  
High Porosity ◽  
Closed Crack ◽  
Fluid Filtration ◽  
Fracture Geometry ◽  
Rubber Sheet ◽  
Foam Rubber ◽  
Reported Study ◽  
Hydraulic Fracture Propagation

<p>        In the present work, a foam rubber sheet installed between two transparent thick flat glasses was used as a physical model of a permeable oil reservoir. The elastic properties of foam rubber and its coefficient of friction on glass are supposed to be measured in separate experiments. In the center of the foam sheet there is a round hole, which is a model of the end face of the well in the oil reservoir. Before the experiment, cuts are made from the hole in opposite directions and to a certain length, simulating a previously closed crack. Using a vacuum pump it is possible to change the pressure of glasses per layer and thereby simulate the increase in "rock pressure" on a productive oil reservoir . A fluid is pumped through the hole in the end of the well. Under the action of fluid filtration, the surface of the walls along the cut of the foam layer are moved apart, forming a gap.The dependence of the pressure gradient on the length of the crack formed was obtained. The overall picture of the growth of hydraulic fracturing is recorded by camera. Continuous physical observations of the formation of a fracture in time allow subsequently predict the optimal fracture geometry.</p><p>The reported study was funded by RFBR, project number №. 20-35-80028 and state task 0146-2019-0007</p>

Investigation of Rupture and Slip Mechanisms of Hydraulic Fractures in Multiple-Layered Formations

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 2292-2307 ◽  
Author(s):  
Jizhou Tang ◽  
Kan Wu ◽  
Lihua Zuo ◽  
Lizhi Xiao ◽  
Sijie Sun ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Hydraulic Fracture ◽  
Fracture Propagation ◽  
Propagation Model ◽  
Rock Deformation ◽  
Hydraulic Fractures ◽  
Fracture Geometry ◽  
Fracture Width ◽  
Hydraulic Fracture Propagation ◽  
Fracture Height

Summary Weak bedding planes (BPs) that exist in many tight oil formations and shale–gas formations might strongly affect fracture–height growth during hydraulic–fracturing treatment. Few of the hydraulic–fracture–propagation models developed for unconventional reservoirs are capable of quantitatively estimating the fracture–height containment or predicting the fracture geometry under the influence of multiple BPs. In this paper, we introduce a coupled 3D hydraulic–fracture–propagation model considering the effects of BPs. In this model, a fully 3D displacement–discontinuity method (3D DDM) is used to model the rock deformation. The advantage of this approach is that it addresses both the mechanical interaction between hydraulic fractures and weak BPs in 3D space and the physical mechanism of slippage along weak BPs. Fluid flow governed by a finite–difference methodology considers the flow in both vertical fractures and opening BPs. An iterative algorithm is used to couple fluid flow and rock deformation. Comparison between the developed model and the Perkins–Kern–Nordgren (PKN) model showed good agreement. I–shaped fracture geometry and crossing–shaped fracture geometry were analyzed in this paper. From numerical investigations, we found that BPs cannot be opened if the difference between overburden stress and minimum horizontal stress is large and only shear displacements exist along the BPs, which damage the planes and thus greatly amplify their hydraulic conductivity. Moreover, sensitivity studies investigate the impact on fracture propagation of parameters such as pumping rate (PR), fluid viscosity, and Young's modulus (YM). We investigated the fracture width near the junction between a vertical fracture and the BPs, the latter including the tensile opening of BPs and shear–displacement discontinuities (SDDs) along them. SDDs along BPs increase at the beginning and then decrease at a distance from the junction. The width near the junctions, the opening of BPs, and SDDs along the planes are directly proportional to PR. Because viscosity increases, the width at a junction increases as do the SDDs. YM greatly influences the opening of BPs at a junction and the SDDs along the BPs. This model estimates the fracture–width distribution and the SDDs along the BPs near junctions between the fracture tip and BPs and enables the assessment of the PR required to ensure that the fracture width at junctions and along intersected BPs is sufficient for proppant transport.

scholarly journals The Experimental Investigation of Hydraulic Fracture Propagation Characteristics in Glutenite Formation

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Zhihong Zhao ◽  
Jianchun Guo ◽  
Shou Ma
Keyword(s):  
Experimental Investigation ◽  
Hydraulic Fracturing ◽  
Hydraulic Fracture ◽  
Large Scale ◽  
Fracture Propagation ◽  
Experimental Results ◽  
Propagation Characteristics ◽  
Fracture Geometry ◽  
Hydraulic Fracture Propagation ◽  
Fracturing Experiments

Hydraulic fracture propagation characteristics in glutenite formation are studied by a series of servo-controlled triaxial large-scale fracturing experiments. The experimental results show that the fractures extend along the gravel and sandstone cementing face, and fracture geometry in glutenite formation is complex, which is similar to network fractures. The phenomenon of the gravel being split has not been observed. In the process of the fracture extension, the extension pressure is fluctuating, and the degree of fluctuation is more drastic with the gravel diameter increase. This paper suggests that using large rate and multislug technology would increase the flow ability of the carrying fluid. The conclusions are significant to hydraulic fracturing in glutenite formation.

Characteristics of Tight Oil in the Dolomicrite Reservoir: A Case Study of Xingouzui Formation, Jianghan Basin, China

2014 ◽  
Vol 522-524 ◽  
pp. 1223-1228
Author(s):  
Min Yue Zhou ◽  
Long Ming Wei ◽  
Ji Rong He ◽  
Qiu Ming Pei ◽  
Wei Li ◽  
...  
Keyword(s):  
Pore Structure ◽  
Oil And Gas ◽  
Physical Property ◽  
Source Rocks ◽  
Tight Oil ◽  
Oil Reservoir ◽  
High Porosity ◽  
Jianghan Basin ◽  
Development Prospects

Low-Xingouzui Formation II reservoir in the Xingou region of Jianghan Basin belongs to tight oil reservoir. By means of study about the geochemical characteristics of source rocks, lithology, physical property and pore structure characteristics, this paper confirms that the source rocks of Low-Xingouzui Formation II are mostly above medium in content of organic matter. The hydrocarbon source rocks are mainly of type II. The thermal maturity of most samples is immature-low mature. Dolomicrite and terrigenous clastic (intraclast) dolomite are the most favorable reservoir facies. The reservoir has mid to high porosity and extremely low permeability, and its space is dominated by dolomite dissolution with micro throat pore structure. This oil reservoir distributes widely and quasi continuous, while good conditions of petroleum formation exist. It could hopefully become new increasing point of Jianghan’s oil and gas output that has broad development prospects and studying value.

Efficient Modeling of Proppant Transport During Three-Dimensional Hydraulic Fracture Propagation

2021 ◽  
Author(s):  
Jiacheng Wang ◽  
Jon Olson
Keyword(s):  
Particle Size ◽  
Hydraulic Fracture ◽  
Three Dimensional ◽  
Fracture Propagation ◽  
Displacement Discontinuity ◽  
Fluid Viscosity ◽  
Fracture Geometry ◽  
Fracture Width ◽  
Proppant Transport ◽  
Hydraulic Fracture Propagation

Abstract We propose an adaptive Eulerian-Lagrangian (E-L) proppant module and couple it with our simplified three-dimensional displacement discontinuity method (S3D DDM) hydraulic fracture model. The integrated model efficiently calculates proppant transport during three-dimensional (3D) hydraulic fracture propagation in multi-layer formations. The results demonstrate that hydraulic fracture height growth mitigates the form of proppant bed, so the proppant placement is more uniform in the hydraulic fracture under a smaller stress contrast. A higher fracturing fluid viscosity improves the suspension of proppant particles and generates a fracture larger in height and width but shorter in length. Lower proppant density and particle size reduce the proppant settling and create more uniform proppant placements, while they do not affect the hydraulic fracture geometry. Moreover, a larger proppant particle size limits the accessibility of the hydraulic fracture to the proppant, so the larger proppant particles do not fill the fracture tip and edge where the fracture width is small.

scholarly journals Numerical methods for solving inverse problems of fluid filtration to a horizontal well

2019 ◽  
Vol 135 ◽  
pp. 01045
Author(s):  
Elena Badertdinova ◽  
Rustem Khairullin
Keyword(s):  
Horizontal Well ◽  
Three Dimensional ◽  
Measuring Instruments ◽  
Oil Reservoir ◽  
Well Bore ◽  
Fluid Filtration ◽  
Proposed Model ◽  
Horizontal Part ◽  
Ill Posed ◽  
Filtration Properties

In this paper, a three-dimensional mathematical model of thermohydrodynamic processes occurring in an oil reservoir exposed by a horizontal well after its launch is constructed. Based on the proposed model and the theory of ill-posed problems, a numerical method is proposed for solving the inverse coefficient problem for determining the filtration properties of an oil reservoir. As the initial information, temperature change curves taken simultaneously by several deep autonomous measuring instruments installed in various sections of the horizontal well bore are used. According to the proposed method, the heterogeneity of the reservoir is evaluated along the horizontal part of the well bore.

scholarly journals Investigation on the mechanism of hydraulic fracture propagation and fracture geometry control in tight heterogeneous glutenites

2021 ◽  
pp. 014459872110362
Author(s):  
Mingyang Zhai ◽  
Dongying Wang ◽  
Lianchong Li ◽  
Zilin Zhang ◽  
Liaoyuan Zhang ◽  
...  
Keyword(s):  
Hydraulic Fracture ◽  
Fracture Propagation ◽  
Injection Rate ◽  
Natural Fracture ◽  
Fluid Viscosity ◽  
Fracture Geometry ◽  
Stimulated Reservoir Volume ◽  
Reservoir Volume ◽  
Fracture Complexity ◽  
Hydraulic Fracture Propagation

The tight heterogeneous glutenites are typically characterized by highly variable lithology, low/ultra-low permeability, significant heterogeneity, and a less-developed natural fracture system. It is of great significance for economic development to improve hydraulic fracture complexity and stimulated reservoir volume. To better understand the hydraulic fracturing mechanism, a large-scale experimental test on glutenite specimens was conducted and the hydraulic fracture propagation behaviors and focal mechanism were analyzed. A three-dimensional numerical model was developed to reproduce the hydraulic fracture evolution process and investigate the effects of operating procedures on hydraulic fracture geometry and stimulated reservoir volume. A simultaneous variable injection rate and fluid viscosity technology was proposed to increase the hydraulic fracture complexity and stimulated reservoir volume. The results indicate that four fracturing behaviors can be observed, namely, penetration, deflection, termination, and bifurcating, in the laboratory experiment. Tensile events tend to appear during the initiation stage of hydraulic fracture growth, while shear events and compressive events tend to appear during the non-planar propagation stage. The shear and compressive mechanisms dominate with an increase in the hydraulic fracture complexity. The variable injection rate technology and simultaneous variable injection rate and fluid viscosity technology are effective techniques for fracture geometry control and stimulated reservoir volume enhancement. The key to improve hydraulic fracture complexity is to increase the net pressure in hydraulic fractures, cause evident pressure fluctuations, and activate or communicate a wide range of natural discontinuities. The results can provide a better understanding of the fracture geometry control mechanism in tight heterogeneous glutenites, and offer a guideline for treatment design and optimization of well performance.

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