Effect of Stress Shadow Caused by Multistage Fracturing from Multiple Well Pads on Fracture Initiation and Near-Wellbore Propagation from Infill Wells

SPE Journal ◽  
2021 ◽  
pp. 1-22
Author(s):  
Xiaohua Wang ◽  
Fengshou Zhang ◽  
Meirong Tang ◽  
Xianfei Du ◽  
Jizhou Tang
Keyword(s):  
Oil And Gas ◽  
Horizontal Wells ◽  
Fracture Initiation ◽  
Injection Rate ◽  
Gas Reservoirs ◽  
Lattice Method ◽  
Integrated Method ◽  
Stress Shadow ◽  
Calculated Stress ◽  
Stimulation Efficiency

Summary Multistage fracturing with multiwell pads (MSFMP) is an essential technology for the efficient development of unconventional oil and gas reservoirs, but the reservoir area between two well pads is often not stimulated. Fracture initiation and near-wellbore propagation from infill horizontal wells drilled with different azimuth from the optimal azimuth in the unstimulated area is poorly understood, largely because of the stress shadow (or induced stress) caused by MSFMP. In this study, we propose an integrated method for calculating the stress shadow caused by MSFMP and then determine optimal completion parameters for infill horizontal wells in the unstimulated connecting area between two well pads. First, we develop a theoretical stress shadow model caused by MSFMP on the basis of the dislocation theory. Considering two extreme cases, fully open and completely closed propped fractures, the range of stress shadow in the unstimulated area after MSFMP of 20 horizontal wells in Platform H of tight reservoirs in the Changqing Oilfield, China, is considered as an example. Second, we import the calculated stress shadow into a 3D perforated fracturing model that is built based on the discrete lattice method. Then, we investigate the influence of perforation technology, horizontal wellbore azimuth, phase angle, and injection rate on fracture initiation and near-wellbore propagation. Our results show that this model is capable of calculating stress shadow at any position and then can be used to optimize the fracturing interval for the middle unstimulated area. We find that appropriate perforation and fracturing parameters significantly decrease the complexity of near-wellbore fractures. The models and results presented in this paper provide a new method and new insight for quantifying and optimizing fracture initiation and propagation for infill horizontal wells to maximize reservoir stimulation efficiency.

The Effect of Well Azimuth or Don't Let Your Landman Plan Your Well Path!

2015 ◽  
Author(s):  
Fen Yang ◽  
Larry K. Britt ◽  
Shari Dunn-Norman
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
Well Performance ◽  
Gas Reservoirs ◽  
Principal Stresses ◽  
Lateral Direction ◽  
Well Completion ◽  
Stimulation Of

Abstract Since the late 1980's when Maersk published their work on multiple fracturing of horizontal wells in the Dan Field, the use of transverse multiple fractured horizontal wells has become the completion of choice and become the “industry standard” for unconventional and tight oil and tight gas reservoirs. Today approximately sixty percent of all wells drilled in the United States are drilled horizontally and nearly all of them are multiple fractured. Because a horizontal well adds additional cost and complexity to the drilling, completion, and stimulation of the well we need to fully understand anything that affects the cost and complexity. In other words, we need to understand the affects of the principal stresses, both direction and magnitude, on the drilling completion, and stimulation of these wells. However, little work has been done to address and understand the relationship between the principal stresses and the lateral direction. This paper has as its goal to fundamentally address the question, in what direction should I drill my lateral? Do I drill it in the direction of the maximum horizontal stress (longitudinal) or do I drill it in the direction of the minimum horizontal stress (transverse)? The answer to this question relates directly back to the title of this paper and please "Don't let your land man drive that decision." This paper focuses on the horizontal well's lateral direction (longitudinal or transverse fracture orientation) and how that direction influences productivity, reserves, and economics of horizontal wells. Optimization studies using a single phase fully three dimensional numeric simulator including convergent non-Darcy flow were used to highlight the importance of lateral direction as a function of reservoir permeability. These studies, conducted for both oil and gas, are used to identify the point on the permeability continuum where longitudinal wells outperform transverse wells. The simulations compare and contrast the transverse multiple fractured horizontal well to longitudinal wells based on the number of fractures and stages. Further, the effects of lateral length, fracture half-length, and fracture conductivity were investigated to see how these parameters affected the decision over lateral direction in both oil and gas reservoirs. Additionally, how does completion style affect the lateral direction? That is, how does an open hole completion compare to a cased hole completion and should the type of completion affect the decision on in what direction the lateral should be drilled? These simulation results will be used to discuss the various horizontal well completion and stimulation metrics (rate, recovery, and economics) and how the choice of metrics affects the choice of lateral direction. This paper will also show a series of field case studies to illustrate actual field comparisons in both oil and gas reservoirs of longitudinal versus transverse horizontal wells and tie these field examples and results to the numeric simulation study. This work benefits the petroleum industry by: Establishing well performance and economic based criteria as a function of permeability for drilling longitudinal or transverse horizontal wells,Integrating the reservoir objectives and geomechanic limitations into a horizontal well completion and stimulation strategy,Developing well performance and economic objectives for horizontal well direction (transverse versus longitudinal) and highlighting the incremental benefits of various completion and stimulation strategies.

scholarly journals GPU-Based Computation of Formation Pressure for Multistage Hydraulically Fractured Horizontal Wells in Tight Oil and Gas Reservoirs

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Rongwang Yin ◽  
Qingyu Li ◽  
Peichao Li ◽  
Yang Guo ◽  
Yurong An ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Superposition Principle ◽  
Horizontal Wells ◽  
Tight Oil ◽  
Formation Pressure ◽  
Gas Reservoirs ◽  
Integral Forms ◽  
Oil And Gas Reservoirs ◽  
Fractured Horizontal Wells ◽  
Tight Oil And Gas

A mathematical model for multistage hydraulically fractured horizontal wells (MFHWs) in tight oil and gas reservoirs was derived by considering the variations in the permeability and porosity of tight oil and gas reservoirs that depend on formation pressure and mixed fluid properties and introducing the pseudo-pressure; analytical solutions were presented using the Newman superposition principle. The CPU-GPU asynchronous computing model was designed based on the CUDA platform, and the analytic solution was decomposed into infinite summation and integral forms for parallel computation. Implementation of this algorithm on an Intel i5 4590 CPU and NVIDIA GT 730 GPU demonstrates that computation speed increased by almost 80 times, which meets the requirement for real-time calculation of the formation pressure of MFHWs.

scholarly journals APPARATUS AND METHODICAL COMPLEX FOR DETERMINATION OF OIL-GAS RESERVOIRS PARAMETERS WHILE DRILLING HORIZONTAL WELLS

2019 ◽  
pp. 20-25
Author(s):  
M. Bondarenko ◽  
V. Kulyk ◽  
Z. Yevstakhevych ◽  
S. Danyliv ◽  
V. Zinenko ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Water Saturation ◽  
Small Diameter ◽  
Horizontal Wells ◽  
Physical Models ◽  
Gas Reservoirs ◽  
Exploration And Production ◽  
Oil And Gas Companies ◽  
Oil Gas ◽  
Logging Tool

The paper is devoted to the basic principles of the trend of logging, namely logging while drilling (LWD), which is new for Ukraine. The LWD technology has a number of advantages over other logging types, in particular, in supplementary exploration and production of hydrocarbons in fields that are in longterm development. In this case, the drilling of horizontal wells, which by productivity is much higher than the vertical ones, is important. For the investigations of horizontal wells, we proposed a universal compact radioactive logging tool with small diameter, which is placed in entire drill collar just before drilling. The combined radioactive logging tool LWD-КПРК-48 (48 mm in diameter) contains dual-spacing modules of neutron logging, neutron-gamma logging, density logging, as well as separately placed gamma-logging unit. Calibration works with the developed combined tool were carried out on physical models of reservoirs in the presence of drill collars and corresponding calibration dependences on porosity and density were obtained. They, together with the developed methods and other data, allow us to determine an extended set of petrophysical parameters, namely, the porosity of water-, oil- and gas-saturated reservoirs, the identification parameters of fluid: water – oil and water – gas, oil-, gas- and water saturation, volume content of oil and gas, etc. Test of a logging tool LWD-КПРК-48 when drilling a horizontal well in an oil-bearing bed showed high informativity and efficiency of product. The created apparatus and methodical complex for the investigation of horizontal oil and gas wells while drilling has several advantages over known analogues, in particular, is universal, convenient, more available to mining and well logging oil and gas companies.

scholarly journals Geochemical Investigation of CO2 Injection in Oil and Gas Reservoirs of Middle East to Estimate the Formation Damage and Related Oil Recovery

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7676
Author(s):  
Ilyas Khurshid ◽  
Imran Afgan
Keyword(s):  
Oil Recovery ◽  
Oil And Gas ◽  
Injection Rate ◽  
Rock Properties ◽  
Co2 Injection ◽  
Formation Damage ◽  
Gas Reservoirs ◽  
Oil And Gas Reservoirs ◽  
Carbon Dioxide Co2 ◽  
Injection Rates

The injection performance of carbon dioxide (CO2) for oil recovery depends upon its injection capability and the actual injection rate. The CO2–rock–water interaction could cause severe formation damage by plugging the reservoir pores and reducing the permeability of the reservoir. In this study, a simulator was developed to model the reactivity of injected CO2 at various reservoir depths, under different temperature and pressure conditions. Through the estimation of location and magnitude of the chemical reactions, the simulator is able to predict the effects of change in the reservoir porosity, permeability (due to the formation/dissolution) and transport/deposition of dissoluted particles. The paper also presents the effect of asphaltene on the shift of relative permeability curve and the related oil recovery. Finally, the effect of CO2 injection rate is analyzed to demonstrate the effect of CO2 miscibility on oil recovery from a reservoir. The developed model is validated against the experimental data. The predicted results show that the reservoir temperature, its depth, concentration of asphaltene and rock properties have a significant effect on formation/dissolution and precipitation during CO2 injection. Results showed that deep oil and gas reservoirs are good candidates for CO2 sequestration compared to shallow reservoirs, due to increased temperatures that reduce the dissolution rate and lower the solid precipitation. However, asphaltene deposition reduced the oil recovery by 10%. Moreover, the sensitivity analysis of CO2 injection rates was performed to identify the effect of CO2 injection rate on reduced permeability in deep and high-temperature formations. It was found that increased CO2 injection rates and pressures enable us to reach miscibility pressure. Once this pressure is reached, there are less benefits of injecting CO2 at a higher rate for better pressure maintenance and no further diminution of residual oil.

Performance Comparison of Transversely and Longitudinally Fractured Horizontal Wells Over Varied Reservoir Permeability

SPE Journal ◽  
2016 ◽  
Vol 21 (05) ◽  
pp. 1537-1553
Author(s):  
Fen Yang ◽  
Larry K. Britt ◽  
Shari Dunn-Norman
Keyword(s):  
Oil And Gas ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
Oil Reservoirs ◽  
Gas Reservoirs ◽  
Lateral Direction ◽  
Reservoir Permeability ◽  
Actual Field ◽  
Oil And Gas Reservoirs ◽  
Fractured Horizontal Wells

Summary Since the late 1980s when Maersk published their work on multiple fracturing of horizontal wells in the Dan field, the use of transverse multiple-fractured horizontal wells has become the completion of choice and the “industry standard” for unconventional and tight-oil and tight-gas reservoirs. Today, approximately 60% of all wells drilled in the United States are drilled horizontally, and nearly all are multiple-fractured. However, little work has been performed to address and understand the relationship between the principal stresses and the lateral direction. This paper has as its goal to fundamentally address the questions: In which direction should I drill my lateral? Do I drill it in the direction of the maximum horizontal stress (longitudinal), or do I drill it in the direction of the minimum horizontal stress (transverse)? This work focuses on how the horizontal well's lateral direction (longitudinal or transverse fracture orientation) influences productivity, reserves, and economics of horizontal wells. Optimization studies, with a single-phase fully 3D numerical simulator including convergent non-Darcy flow, were used to highlight the importance of lateral direction as a function of reservoir permeability. The simulations, conducted for both oil and gas formations over a wide range of reservoir permeability (50 nd–5 md), compare and contrast the performance of transversely multiple-fractured horizontal wells with longitudinally fractured horizontal wells in terms of rate, recovery, and economics. This work also includes a series of field case studies to illustrate actual field comparisons of longitudinal vs. transverse horizontal well performance in both oil and gas reservoirs, and to tie these field examples to the numerical-simulation study. Further, the effects of lateral length, fracture half-length, and fracture conductivity were investigated to see how these parameters affect the decision of lateral direction in both oil and gas reservoirs. In addition, this study seeks to address how completion style (openhole or cased-hole completion) affects the selection of lateral direction. The results show the existence of a critical reservoir permeability, above which longitudinal fractured horizontal wells outperform transverse fractured horizontal wells. With openhole completions, the critical permeability is 0.04 md for gas reservoirs and 0.4 md for oil reservoirs. With cased-hole completions, longitudinal horizontal wells are preferred at a reservoir permeability above 1.5 md in gas reservoirs, and transverse horizontal wells are preferable over the entire permeability range of this study (50 nd–5 md) in oil reservoirs. These are new findings. Previous work generally suggested that longitudinal horizontal wells are a better option for gas reservoirs with permeability over 0.5 md, and for oil reservoirs with permeability over 10 md. This work extends prior study to include unconventional reservoir permeabilities. It provides critical permeability values for both gas and oil reservoirs, which are validated by the good compliance between actual field-case history and simulation results. This work also demonstrates a larger impact of completion method over fracture design. These findings could guide field operations and serve as a reference for similar studies.

Simulation of proppant transport and fracture plugging in the framework of a radial hydraulic fracturing model

2020 ◽  
Vol 35 (6) ◽  
pp. 325-339
Author(s):  
Vasily N. Lapin ◽  
Denis V. Esipov
Keyword(s):  
Numerical Model ◽  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Injection Rate ◽  
Fluid Injection ◽  
Subtraction Technique ◽  
Gas Industry ◽  
Proppant Transport ◽  
Hydraulic Fracture Propagation

AbstractHydraulic fracturing technology is widely used in the oil and gas industry. A part of the technology consists in injecting a mixture of proppant and fluid into the fracture. Proppant significantly increases the viscosity of the injected mixture and can cause plugging of the fracture. In this paper we propose a numerical model of hydraulic fracture propagation within the framework of the radial geometry taking into account the proppant transport and possible plugging. The finite difference method and the singularity subtraction technique near the fracture tip are used in the numerical model. Based on the simulation results it was found that depending on the parameters of the rock, fluid, and fluid injection rate, the plugging can be caused by two reasons. A parameter was introduced to separate these two cases. If this parameter is large enough, then the plugging occurs due to reaching the maximum possible concentration of proppant far from the fracture tip. If its value is small, then the plugging is caused by the proppant reaching a narrow part of the fracture near its tip. The numerical experiments give an estimate of the radius of the filled with proppant part of the fracture for various injection rates and leakages into the rock.

scholarly journals Ball sealer tracking and seating of temporary plugging fracturing technology in the perforated casing of a horizontal well

2021 ◽  
pp. 014459872110204
Author(s):  
Wan Cheng ◽  
Chunhua Lu ◽  
Guanxiong Feng ◽  
Bo Xiao
Keyword(s):  
Critical Parameter ◽  
Fluid Velocity ◽  
Stable State ◽  
Horizontal Wells ◽  
Terminal Velocity ◽  
Injection Rate ◽  
Fracturing Fluid ◽  
Perforation Hole ◽  
Horizontal Wellbore ◽  
Tight Reservoirs

Multistaged temporary plugging fracturing in horizontal wells is an emerging technology to promote uniform fracture propagation in tight reservoirs by injecting ball sealers to plug higher-flux perforations. The seating mechanism and transportation of ball sealers remain poorly understood. In this paper, the sensitivities of the ball sealer density, casing injection rate and perforation angle to the seating behaviors are studied. In a vertical wellbore section, a ball sealer accelerates very fast at the beginning of the dropping and reaches a stable state within a few seconds. The terminal velocity of a non-buoyant ball is greater than the fluid velocity, while the terminal velocity of a buoyant ball is less than the fluid velocity. In the horizontal wellbore section, the terminal velocity of a non-buoyant or buoyant ball is less than the fracturing fluid flowing velocity. The ball sealer density is a more critical parameter than the casing injection rate when a ball sealer diverts to a perforation hole. The casing injection rate is a more critical parameter than the ball sealer density when a ball sealer seats on a perforation hole. A buoyant ball sealer associated with a high injection rate of fracturing fluid is highly recommended to improve the seating efficiency.

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