Evaluation of the Proppant-Pack Permeability in Fiber-Assisted Hydraulic 
Fracturing Treatments for Low-Permeability Formations

Bulova, Marina; Nosova, Ksenia; Lassek, John; Willberg, D. M.

doi:10.2523/100556-ms

Cited by 3 publications

(3 citation statements)

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“…And the fracturing fliud with less viscosity normally leads to better fracture height containment and thus enhance the fracture half-length to some extent, [J. Engels et al 2004;M. Bulova et al 2006].…”

Section: Fracturing Techniques and Fracturing Design Principlesmentioning

confidence: 99%

Unlock Shale Oil Reserves Using Advanced Fracturing Techniques: A Case Study in China

et al. 2013

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Development of unconventional resources has become major focus in China in the recent years as the growth of energy demands. Many pilot projects on shale oil reservoirs have been initiated to seek for economic development with modern hydraulic fracturing technologies. Fracturing these reservoirs is quite challenging and requires not only large reservoir contacts but also high fracture conductivity in both primary fracture and fracture networks since oil viscosity is several magnitudes higher than natural gas. Vertical fracture connectivity is also an issue in many cases due to lamination of shale-rich layers with thin siliceous and calcareous beds. This typical sedimentary feature may result in either short fracture height or pinch-point in vertical fracture profile due to proppant embedment in shale-rich layers.The paper presents a shale oil case study in Northern Songliao Basin in China in which many fracturing treatments have been attempted in the past without success. Two existing vertical wells drilled in 1989 were used to study appreciate fracturing techniques and demonstrate the possibility of economic production before evaluating horizontal well completion. The paper illustrates optimization of treatment strategy and design by integrating detailed reservoir characterization, fracture simulation using unconventional fracture model and numerical reservoir simulations. It also introduces an innovative fiber diversion technique for improved vertical fracture coverage and proppant placement together with real time fracture monitoring for treatment optimization.After increased understanding from the treatment on the first well, the treatment on the second well was quite successful and the well produces 30 bopd after the treatment, which is the first ever economic production in the field. The first month production history also matches with the forecast very well, which increases the confidence of extending the practice to the entire field as well as subsequent horizontal well evaluation. TX 75083-3836, U.S.A., fax +1-972-952-9435

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Section: Fracturing Techniques and Fracturing Design Principlesmentioning

confidence: 99%

Unlock Shale Oil Reserves Using Advanced Fracturing Techniques: A Case Study in China

et al. 2013

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“…The final test was the proppant pack conductivity experiment and comparison of the conventional fracturing fluid with the fluid containing fibers. The equipment setup and the procedures of proppant pack conductivity experiment were described in detail by Bulova et al (2006). The test was conducted with the polymer loading 3.0 kg/m 3 without fibers and with fibers in the concentration 3.0 kg/m 3 ; also, the test with lower polymer loading (2.8 kg/m 3 ) without fibers was conducted.…”

Section: Fiber Decomposition Testmentioning

confidence: 99%

Successful Implementation of Fiber-Laden Fluid for Hydraulic Fracturing of Jurassic Formations in Western Siberia

et al. 2013

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The Urnenskoe field is located in the Tyumen region, Western Siberia. The main production target is the J1 formation belonging to the upper Jurassic Vasyugansk suite. Subsurface geology of the Urnenskoe field features the lithological heterogeneity of the J1 formation with high-and low-permeability interlayers and considerable petroleum reserves in upper low-permeability formation intervals. Oil and water have highly different viscosities permitting rapid water breakthrough into the formation.The first hydraulic fracturing operations were carried out at the Urnenskoe field in 2010. Because there are rich oilsaturated zones in the low-permeability upper zone of the reservoir, the properties of the fracturing fluid to transport proppant and its ability to prevent settling during both the pumping and when the fracture is closing are decisive for the well productivity after the fracturing operation. Fracturing fluid with degradable fibers was selected to achieve these properties during hydraulic fracturing. The fibers create a reinforcing net within the fracturing fluid with proppant and mechanically assist the transportation and suspension of the proppant grains. The temperature decomposes the fibers when the fracture is closed. In addition, the fibers allow lowering the polymer concentration in the fracturing fluid, thus enabling control of the fracture vertical growth and decreasing proppant pack damage.Since there are no all-season roads and it is difficult to approach the Urnenskoe field in the summer, there was no fracturing fleet capable of performing an operation utilizing the fluid with degradable fibers in July 2011. Therefore, 7 conventional fracturing operations were performed; these can be used to compare the effectiveness of conventional fracturing with another 23 operations in which the fibers were used. These operations revealed that the wells in which the fibers were used had a dimensionless productivity index that was 33% higher, and this effect remained stable. Also, for the wells with the fiber application, the average cumulative oil production for 5 months was 2,245 tons higher (recalculated for one well). These results confirm the effectiveness of hydraulic fracturing with degradable fibers in the Urnenskoe field. The successful experience of using hydraulic fracturing with degradable fibers at the Urnenskoe field, laboratory tests of the fiber-laden fluid, analysis of well productivity, and particular applications of the technology provide information to guide further optimization. In addition, the technology has been applied in the Jurassic formations of the neighboring Ust-Tegusskoe field, where a considerable productivity gain was achieved compared with the conventional fracturing operations.

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“…Two identical retained conductivity tests were performed on a conventional and rod-shaped proppant pack in a standard conductivity setup (Bulova, at al., 2006). In these tests, the percentage of initial (baseline) pack permeability was obtained after fracturing fluid leakoff and subsequent pack cleanup to brine.…”

Section: Fracture Cleanupmentioning

confidence: 99%

A Unique, Large-Scale Computer Tomography Scanner: Investigation of Fracture Cleanup with Different Materials

et al. 2011

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Hydraulic fracturing is a widely used technique for production enhancement. One critical property of a hydraulic fracture is the fracture conductivity, which has a direct impact on the productivity and hence, the economics of the stimulated well. Several laboratory techniques have been developed to characterize the materials that are placed in the fracture and influence its conductivity. Conductivity laboratory measurements have become a routine experiment with well-established procedures and setups aimed at simulating downhole conditions. However, correlating the performance of materials in a conventional laboratory setup with their performance in real conditions is not straightforward. This problem occurs because conventional laboratory setups are of limited length scale and fail to capture processes and variations that occur at a scale of the order of, or exceeding, the dimensions of the conductivity cell. Also, even if conventional setups provide accurate and reproducible measurements, they fail to provide fundamental, in-depth understanding of the actual processes that occur at the pore scale, occur in the fracture, and influence the fracture conductivity.A unique, large-scale X-ray computer tomography (CT) setup improves understanding of the factors influencing fracture conductivity. The state-of-the-art setup allows taking high-resolution scans of a proppant pack under conditions similar to an actual fracture. The setup provides unique insight into static and dynamic phenomena occurring at the proppant and the pore scale. The use of imaging software then provides an accurate 3D image over the entire length of the proppant pack. Computer models of flow in porous media can then be used to predict the flow and its parameters in the propped fracture and its porous network specified by the high-resolution images. Moreover, the setup scale (1 m long) is much larger than that of a conventional conductivity cell (20 cm long). The larger dimensions are adequate to capture heterogeneous processes such as fracture cleanup.The performance of the new setup was validated using baseline proppant pack conductivity and non-Darcy flow coefficients experiments. An example was also shown where the unique X-ray CT setup was used for investigating fracture cleanup of new, elongated rod-shaped nondeformable high-strength proppant compared with conventional spherical proppant. The CT images show how the new proppant provides a better fracture cleanup compared with spherical proppant. For both cases, images showing the distribution of residual gel saturation highlight how pore volume geometry affects fracture cleanup.

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Evaluation of the Proppant-Pack Permeability in Fiber-Assisted Hydraulic Fracturing Treatments for Low-Permeability Formations

Cited by 3 publications

References 1 publication

Unlock Shale Oil Reserves Using Advanced Fracturing Techniques: A Case Study in China

Unlock Shale Oil Reserves Using Advanced Fracturing Techniques: A Case Study in China

Successful Implementation of Fiber-Laden Fluid for Hydraulic Fracturing of Jurassic Formations in Western Siberia

A Unique, Large-Scale Computer Tomography Scanner: Investigation of Fracture Cleanup with Different Materials

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