Ability to Use DFIT to Replace the Minifrac in Sandstone Formations for Reservoir Characterizations

2021 ◽  
Author(s):  
Mohamed A. Gabry ◽  
Samuel A. Thabet ◽  
Emad Abdelhaliem ◽  
Ahmed Algarhy ◽  
Maharaja Palanivel
Keyword(s):  
Hydraulic Fracture ◽  
Reservoir Characterization ◽  
Deep Understanding ◽  
Good Method ◽  
Job Design ◽  
High Rate ◽  
Stress Profile ◽  
Fracturing Fluid ◽  
Reservoir Properties ◽  
Fracture Geometry

Abstract One of essential parts of hydraulic fracture job design optimization in deep sandstone formations is to conduct a minifrac test using fracture fluid to identify the closure pressure for calibration of the stress profile and to calibrate the leak-off coefficient of the fracturing fluid, but the test could not provide good understanding for reservoir properties of permeability, reservoir pressure, and intensity of natural fractures. By conducting the actual DFIT (Diagnostic Fracture Injection Test) and minifrac in more than thirty wells in different formations from different fields, several leak-off behaviors are observed and several conclusions can be reached by integrating minifrac, DFIT, geologic settings information, and production data. With the experience of conducting high rate and low rate DFIT before minifrac jobs, we can conclude that there are several benefits for the DFIT by replacing the minifrac, which conventionallyusesg a polymer fracturing fluid, with a non-wall-building fluid consisting mainly of water from the operations and job design perspective, and from the post frac production perspective. DFIT with water can introduce the best methodology to detect the induced complexity that may cause hydraulic fracture job cancellation in cases of detecting high complexity value early before rig movement. Implementing DFIT in a complete hydraulic fracturing design, execution and evaluation workflow can provide a deep understanding of the fracture geometry propagation and reservoir characterization. The main disadvantages of the DFIT is that it requires a long leak-off observation period but that can be minimized in the mD range of sandstone permeability. This paper introduces DFIT in sandstone formations as a good method for integration between the geology, reservoir management, and fracture operations. The paper provides the operational and integral benefits of replacing minifrac and fracturing fluid with DFIT and water in deep sandstone formations, which provides more accurate data analysis because testing is done with same fluid. In addition, it can reduce fracture operations cost by 10%.

Validation of flow capacity and state-of-stress models in unconventional reservoirs by implementation of numerical models of diagnostic fracture injection tests

2019 ◽  
Vol 38 (6) ◽  
pp. 465-472
Author(s):  
Hernán Buijs ◽  
Jorge Ponce ◽  
Paul Veeken
Keyword(s):  
Development Strategy ◽  
Hydraulic Fracture ◽  
Reservoir Characterization ◽  
Numerical Models ◽  
Solution Space ◽  
Production Performance ◽  
Fracture Geometry ◽  
Field Development ◽  
Flow Capacity ◽  
Planar Shear

Diagnostic fracture injection tests contain critical information for reservoir characterization and hydraulic fracturing design, defining every input and output of the simulation modeling process. They help to assess the expected fracture geometry, proppant pack conductivity, formation flow capacity, and optimum hydraulic fracture design. At the same time, these data provide the necessary means to place a frac job adequately. However, interpretation challenges and inherent modeling nonuniqueness demonstrate the need for more constraints to reduce the solution space. Proprietary workflows have been applied using a 3D planar shear decoupled hydraulic fracture simulator to several vertical wells in the Vaca Muerta play in Argentina. The generated information makes it possible to build models consistent with multiple independent measurements from bottom-hole gauges, near wellbore, and far-field assessments of fracture geometry, which permit us to better understand production performance of the wells. The proposed workflow can be utilized to collapse the learning curve in a significant and meaningful way, playing a vital role in the optimization of horizontal wells and the field development strategy.

High Accuracy Estimation of Hydraulic Fracture Geometry Using Crosswell Electromagnetics

2021 ◽  
Author(s):  
Shubham Mishra ◽  
Vinil Reddy
Keyword(s):  
Hydraulic Fracture ◽  
Horizontal Wells ◽  
Hydraulic Fractures ◽  
Calibration Data ◽  
Formation Water ◽  
Fracturing Fluid ◽  
Production Forecast ◽  
Fracture Geometry ◽  
Field Development ◽  
Well Completion

Abstract Unconventional resources, which are typically characterized by poor porosity and permeability are being economically developed only after the introduction of hydraulic fracturing (HF) technology, which is required to stimulate the hydrocarbon flow from these impermeable/tight reservoir rocks. Since 1960, HF has been extensively used in the industry. HF is the process of (1) injecting viscous gel fluids through the wellbore into the subterranean hydrocarbon formation, at high pressures sufficient enough to exceed tensile strength of the rock and hydraulically induce cracks/fractures (2) followed by injecting proppant-laden fluid into the open fractures and packing up the fracture with proppant pack, after the injected fluid leaks off into formation. The resultant proppant pack keeps the induced fracture propped open and thus creates a highly conductive flow path for the hydrocarbon to flow from the far-field subterranean formation into the wellbore. Most the modern wells in unconventional reservoirs are horizontal/near-horizontal wells that are completed with large multiple HF treatments across the entire length of the horizontal wellbore (lateral), to increase the reservoir contact per well. Productivity of these wells is dictated by the stimulated reservoir volume (SRV), which is dependent on the number of fractures and conductive hydraulic fracture surface area of each fracture that is propped open. Therefore, estimation of the hydraulic fracture geometry (HFG) dimensions has become very critical for any unconventional field development. Key dimensions are hydraulic fracture length, height, and orientation, which are required to assess the optimum configuration of fracturing, well completion, and reservoir management strategy to achieve maximum production. Designs can be assessed based on HFG observations, and infill well trajectories, spacing, etc. can be planned for further field development. This workflow proposes a method to estimate and model all or at least two parameters of HFG in predominantly horizontal or nearly horizontal wells by use of interwell electromagnetic recordings. The foundation of this workflow is the difference in salinity, or more precisely resistivity, of the fracturing fluid and the resident fluid (hydrocarbon or formation water). The fracturing fluid is usually significantly less resistive than the hydrocarbon that is the dominant resident fluid where fracturing is usually conducted, or less resistive than the formation water in case the HF occurs in high water saturation regions. Therefore, the resistivity contrast between the two fluids will demarcate the boundary of hydraulic fractures and thus help in precisely modeling some or all parameters of HFG. The interwell recordings can be interpreted along a 2D plane between the two wells, one of them bearing the transmitter and the other with the receiver. The interpretations along a 2D plane can be used to calibrate a 3D unstructured HF model, thereby introducing a reliable calibration input that did not exist before. There can be multiple such 2D planes as more than one well can have a receiver, and, in that case, the 3D HF model has more calibration data and is even more precise. The reason this workflow significantly improves precision in HFG estimation and modeling is that it provides the ability to demarcate only the open portion of the HF and not the entire volume where pumping fluid entered, which would include parts that closed too quickly to contribute to the production from the well. Today, the industry, by its best methods, can only see the entire rock volume that broke due to fracturing, although significant parts of that broken volume might not be contributing to the production and thus are irrelevant in the 3D models upon which important decisions such as production forecast and project economics are based.

Data Analytics to Help Improve Hydraulic Fracture Geometry Prediction Using Support Vector Regression: Case Study

2020 ◽  
Author(s):  
Avinash Wesley ◽  
Bharat Mantha ◽  
Ajay Rajeev ◽  
Aimee Taylor ◽  
Mohit Dholi ◽  
...  
Keyword(s):  
Support Vector Regression ◽  
Hydraulic Fracture ◽  
Data Analytics ◽  
Support Vector ◽  
Fracture Geometry

A new approach to the hydraulic fracture geometric dimensions determination

2017 ◽  
Vol 12 (1) ◽  
pp. 126-134
Author(s):  
A.M. Ilyasov
Keyword(s):  
Exact Solution ◽  
Hydraulic Fracture ◽  
Pressure Gauge ◽  
Hyperbolic Type ◽  
Fluid Injection ◽  
Fracturing Fluid ◽  
New Approach ◽  
Gauge Data ◽  
Bottomhole Pressure ◽  
Half Length

Based on the generalized Perkins-Kern-Nordgren model (PKN) for the development of a hyperbolic type vertical hydraulic fracture, an exact solution is obtained for the hydraulic fracture self-oscillations after terminating the fracturing fluid injection. These oscillations are excited by a rarefaction wave that occurs after the injection is stopped. The obtained solution was used to estimate the height, width and half-length of the hydraulic fracture at the time of stopping the hydraulic fracturing fluid injection based on the bottomhole pressure gauge data.

Latest developments in seismic texture analysis for subsurface structure, facies, and reservoir characterization: A review

Geophysics ◽  
2011 ◽  
Vol 76 (2) ◽  
pp. W1-W13 ◽  
Author(s):  
Dengliang Gao
Keyword(s):  
Texture Analysis ◽  
Reservoir Characterization ◽  
Preliminary Test ◽  
Seismic Facies ◽  
Least Squares Regression ◽  
Reservoir Properties ◽  
Seismic Amplitude ◽  
Texture Model ◽  
Facies Classification ◽  
Analysis Window

In exploration geology and geophysics, seismic texture is still a developing concept that has not been sufficiently known, although quite a number of different algorithms have been published in the literature. This paper provides a review of the seismic texture concepts and methodologies, focusing on latest developments in seismic amplitude texture analysis, with particular reference to the gray level co-occurrence matrix (GLCM) and the texture model regression (TMR) methods. The GLCM method evaluates spatial arrangements of amplitude samples within an analysis window using a matrix (a two-dimensional histogram) of amplitude co-occurrence. The matrix is then transformed into a suite of texture attributes, such as homogeneity, contrast, and randomness, which provide the basis for seismic facies classification. The TMR method uses a texture model as reference to discriminate among seismic features based on a linear, least-squares regression analysis between the model and the data within an analysis window. By implementing customized texture model schemes, the TMR algorithm has the flexibility to characterize subsurface geology for different purposes. A texture model with a constant phase is effective at enhancing the visibility of seismic structural fabrics, a texture model with a variable phase is helpful for visualizing seismic facies, and a texture model with variable amplitude, frequency, and size is instrumental in calibrating seismic to reservoir properties. Preliminary test case studies in the very recent past have indicated that the latest developments in seismic texture analysis have added to the existing amplitude interpretation theories and methodologies. These and future developments in seismic texture theory and methodologies will hopefully lead to a better understanding of the geologic implications of the seismic texture concept and to an improved geologic interpretation of reflection seismic amplitude.

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