A. Alzahabi, A. Trindade, A. Kamel, A. Harouaka, W. Baustian, C. Campbell
One of the continuing puzzle pieces for all unconventional plays is drawdown (DD) technique for optimal Return on Investment (ROI). A solid approach to determine this valuable piece of information has yet to be found, as many operators are reluctant to reveal the production, pressure, and completion data required. Among multiple parameters, various completion and spacing parameters add to the complexity of the problem. This paper aims to determine which drawdown strategy leads to the highest return in the Anadarko Basin,, specifically evaluating the Woodford and Mayes formation. Several drawdown techniques were used within the Anadarko Basin in conjunction with different completion techniques. Private production and completion data were analyzed and combined with well log analysis in conjunction with data analytics tools. This case study explores a new strategy to drawdown producing wells within the Anadarko basin to achieve ultimate ROI. We perform data analytics utilizing analytics (scatterplot smoothing) to develop a relationship between two dependent variables Estimated Ultimate Recovery (EUR) and Initial Production (IP) for 180 days of Oil vs. drawdown. We present a model that evaluates horizontal well production based on drawdown parameters. Key data were estimated using reservoir and production parameters. The data led to determination of the most optimal drawdown technique for different reservoirs within the Anadarko Basin. This result may help professionals fully understand the Anadarko Basin. By use of these optimal parameters, we hope to completely understand the best way to drawdown wells when they are drilled simultaneously. Our findings and workflow within the Woodford and Mayes formations may be applied to various plays and formations across the unconventional play spectrum. Optimal drawdown techniques in unconventional reservoirs could add billions of dollars in revenue to a company's portfolio and increase rate of return dramatically, as well as offer a new understanding of the reservoirs in which we are dealing with.
{"title":"Data Determine the Optimal Drawdown for Woodford and Mayes in the Anadarko Basin","authors":"A. Alzahabi, A. Trindade, A. Kamel, A. Harouaka, W. Baustian, C. Campbell","doi":"10.2118/201660-ms","DOIUrl":"https://doi.org/10.2118/201660-ms","url":null,"abstract":"\u0000 One of the continuing puzzle pieces for all unconventional plays is drawdown (DD) technique for optimal Return on Investment (ROI). A solid approach to determine this valuable piece of information has yet to be found, as many operators are reluctant to reveal the production, pressure, and completion data required. Among multiple parameters, various completion and spacing parameters add to the complexity of the problem. This paper aims to determine which drawdown strategy leads to the highest return in the Anadarko Basin,, specifically evaluating the Woodford and Mayes formation. Several drawdown techniques were used within the Anadarko Basin in conjunction with different completion techniques. Private production and completion data were analyzed and combined with well log analysis in conjunction with data analytics tools. This case study explores a new strategy to drawdown producing wells within the Anadarko basin to achieve ultimate ROI. We perform data analytics utilizing analytics (scatterplot smoothing) to develop a relationship between two dependent variables Estimated Ultimate Recovery (EUR) and Initial Production (IP) for 180 days of Oil vs. drawdown. We present a model that evaluates horizontal well production based on drawdown parameters. Key data were estimated using reservoir and production parameters. The data led to determination of the most optimal drawdown technique for different reservoirs within the Anadarko Basin. This result may help professionals fully understand the Anadarko Basin. By use of these optimal parameters, we hope to completely understand the best way to drawdown wells when they are drilled simultaneously. Our findings and workflow within the Woodford and Mayes formations may be applied to various plays and formations across the unconventional play spectrum. Optimal drawdown techniques in unconventional reservoirs could add billions of dollars in revenue to a company's portfolio and increase rate of return dramatically, as well as offer a new understanding of the reservoirs in which we are dealing with.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"168 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127582235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A pressure deconvolution technique based on ridge regression with existing convolution features was explored and reinterpreted to frame a new optimization problem structure. We found a way to split the feature matrix into a deconvolution part and a smoothing part that handle each effect independently. The deconvolution part is comprised of a convolution matrix (Toeplitz matrix) for discrete-time convolution while the smoothing part is composed of a basis function of the impulse response. Hence, this formulation preserves linearity (a superposition of pressure solution) and the kernel for nonlinear mapping (e.g., polynomial kernel, radial basis function kernel, etc.) is effective only on the smoothing part (a basis function of impulse response). Importantly, the key idea of existing convolution feature is the modelling of the impulse response with a linear combination of a basis functions. For single-well pressure behavior, ridge regression often struggles with high-frequency measurements that contain multistage responses. An impulse response might share similar functional characteristics, for example wellbore storage and pseudosteady state are both linear responses but there is only one linear basis function in the ridge regression which cannot describe them both. In traditional well test interpretation, the engineer is typically focused on certain parts of the impulse response on a log-scale, to identify reservoir behavior (e.g., early-time for wellbore storage, transient-time for infinite acting radial flow, late-time for boundary effect, etc.). Analogously, a basis function could be formed from multiple pressure responses in each log-interval (inherent from a solution of the diffusion equation) then bridged together with a constraint on function value and its derivative at each interval boundary. This is the basic principle of spline regression that has more flexibility in terms of function expression. In addition, it also subsumes ridge regression with Laplacian regularization. For multiwell pressure behavior, additional basis functions are included to handle interference responses. Typically, the exponential integral is approximated with a logarithm function for single-well pressure response which is also one of the basis functions in previous convolution features. Nonetheless, interference pressure response is more subtle and its solution could not be easily approximated, which previously resulted in a poor fitting using earlier methods. By inspection of the convergent series of the exponential integral, its higher-order terms are associated with 1/tm that can be easily included as a basis function to enhance the capability of the model and capture the detail of the interference test that is essential for multiwell problems. A full extension to multiwell problems is also presented with the additional derivative constraint for the impulse response and symmetry constraint. Finally, we can quantify the sensitivity of the deconvolution proc
{"title":"Revisiting Machine Learning Approaches For Pressure Data Deconvolution","authors":"K. Wongpattananukul, R. Horne","doi":"10.2118/201335-ms","DOIUrl":"https://doi.org/10.2118/201335-ms","url":null,"abstract":"\u0000 A pressure deconvolution technique based on ridge regression with existing convolution features was explored and reinterpreted to frame a new optimization problem structure. We found a way to split the feature matrix into a deconvolution part and a smoothing part that handle each effect independently. The deconvolution part is comprised of a convolution matrix (Toeplitz matrix) for discrete-time convolution while the smoothing part is composed of a basis function of the impulse response. Hence, this formulation preserves linearity (a superposition of pressure solution) and the kernel for nonlinear mapping (e.g., polynomial kernel, radial basis function kernel, etc.) is effective only on the smoothing part (a basis function of impulse response). Importantly, the key idea of existing convolution feature is the modelling of the impulse response with a linear combination of a basis functions.\u0000 For single-well pressure behavior, ridge regression often struggles with high-frequency measurements that contain multistage responses. An impulse response might share similar functional characteristics, for example wellbore storage and pseudosteady state are both linear responses but there is only one linear basis function in the ridge regression which cannot describe them both. In traditional well test interpretation, the engineer is typically focused on certain parts of the impulse response on a log-scale, to identify reservoir behavior (e.g., early-time for wellbore storage, transient-time for infinite acting radial flow, late-time for boundary effect, etc.). Analogously, a basis function could be formed from multiple pressure responses in each log-interval (inherent from a solution of the diffusion equation) then bridged together with a constraint on function value and its derivative at each interval boundary. This is the basic principle of spline regression that has more flexibility in terms of function expression. In addition, it also subsumes ridge regression with Laplacian regularization.\u0000 For multiwell pressure behavior, additional basis functions are included to handle interference responses. Typically, the exponential integral is approximated with a logarithm function for single-well pressure response which is also one of the basis functions in previous convolution features. Nonetheless, interference pressure response is more subtle and its solution could not be easily approximated, which previously resulted in a poor fitting using earlier methods. By inspection of the convergent series of the exponential integral, its higher-order terms are associated with 1/tm that can be easily included as a basis function to enhance the capability of the model and capture the detail of the interference test that is essential for multiwell problems. A full extension to multiwell problems is also presented with the additional derivative constraint for the impulse response and symmetry constraint. Finally, we can quantify the sensitivity of the deconvolution proc","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116062435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Zhu, Julian Uribe, Daniel Sohn, D. Hill, A. Ugursal, C. Shuchart, Clay Purdy, M. Weissenberger
In carbonate matrix acidizing, the critical design parameters are interstitial velocity and pore volume to breakthrough for wormhole propagation at the optimal condition (vi,opt and PVBT,opt). These two parameters are determined by the formation rock properties including permeability, porosity, temperature, pressure, and mineralogy, and the acid system that will be used. HCl has been the most commonly used acid in carbonate acidizing. However, the efficiency of wormhole creation using strong HCl solutions is sometimes low because the injection rate needed for optimal wormhole propagation is not attainable, especially when applied to long completion intervals and/or low permeability carbonates. High concentration HCl solutions also raise safety and environmental concerns. When retarded acid systems are used to overcome these challenges, the efficiency of acid stimulation often suffers from low reaction rate and low dissolving power. This study presents testing results of a modified acid system that has controlled reaction rate with favorable wormhole propagation characteristics, especially at low interstitial velocities. Due to the increased activation energy barriers utilized in these modified-acid systems, it is possible to control the reaction rate of the hydrogen proton and optimize the wormholing effect based on the completion method and formation specifications. Single phase modified acid systems are applicable and can be tailored for limestone and chalk formations. Laboratory linear core flooding experiments and acid jetting experiments were conducted to study the wormhole efficiency with the new acid systems. Core flood tests were designed to generate the wormhole efficiency curves and compare the results from the tests with HCl under the same conditions. Jetting experiments were conducted to evaluate the structure of cavity and wormhole development, and the results were also compared with HCl injection at similar conditions. Results from the experimental study were then used to compare the acid systems through wormhole efficiency curves and CT scans of acid dissolution structures. The experimental results showed clear advantages of the modified acid systems. The modified acids have similar or better wormhole efficiency parameters compared with HCl having comparable dissolving power. When combined with acid jetting, further improvement in wormhole growth in low permeability limestone is achieved. In addition to minimizing the hazardous exposure levels, corrosion rates, and negative HS&E properties compared with hydrochloric acid, the new acid system provides the positive aspects of solubilizing ability and reaction rates thus improving optimal wormhole conditions (lower vi,opt and PVBT,opt). This potentially allows for better stimulation results with less fluid required.
{"title":"Decision letter for \"A modified acid system to enhance carbonate matrix acid stimulation: An experimental study\"","authors":"D. Zhu, Julian Uribe, Daniel Sohn, D. Hill, A. Ugursal, C. Shuchart, Clay Purdy, M. Weissenberger","doi":"10.2118/201704-ms","DOIUrl":"https://doi.org/10.2118/201704-ms","url":null,"abstract":"\u0000 In carbonate matrix acidizing, the critical design parameters are interstitial velocity and pore volume to breakthrough for wormhole propagation at the optimal condition (vi,opt and PVBT,opt). These two parameters are determined by the formation rock properties including permeability, porosity, temperature, pressure, and mineralogy, and the acid system that will be used. HCl has been the most commonly used acid in carbonate acidizing. However, the efficiency of wormhole creation using strong HCl solutions is sometimes low because the injection rate needed for optimal wormhole propagation is not attainable, especially when applied to long completion intervals and/or low permeability carbonates. High concentration HCl solutions also raise safety and environmental concerns. When retarded acid systems are used to overcome these challenges, the efficiency of acid stimulation often suffers from low reaction rate and low dissolving power. This study presents testing results of a modified acid system that has controlled reaction rate with favorable wormhole propagation characteristics, especially at low interstitial velocities.\u0000 Due to the increased activation energy barriers utilized in these modified-acid systems, it is possible to control the reaction rate of the hydrogen proton and optimize the wormholing effect based on the completion method and formation specifications. Single phase modified acid systems are applicable and can be tailored for limestone and chalk formations. Laboratory linear core flooding experiments and acid jetting experiments were conducted to study the wormhole efficiency with the new acid systems. Core flood tests were designed to generate the wormhole efficiency curves and compare the results from the tests with HCl under the same conditions. Jetting experiments were conducted to evaluate the structure of cavity and wormhole development, and the results were also compared with HCl injection at similar conditions. Results from the experimental study were then used to compare the acid systems through wormhole efficiency curves and CT scans of acid dissolution structures.\u0000 The experimental results showed clear advantages of the modified acid systems. The modified acids have similar or better wormhole efficiency parameters compared with HCl having comparable dissolving power. When combined with acid jetting, further improvement in wormhole growth in low permeability limestone is achieved. In addition to minimizing the hazardous exposure levels, corrosion rates, and negative HS&E properties compared with hydrochloric acid, the new acid system provides the positive aspects of solubilizing ability and reaction rates thus improving optimal wormhole conditions (lower vi,opt and PVBT,opt). This potentially allows for better stimulation results with less fluid required.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117246299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polymer flooding is well-established and effective independent technique for improving oil recovery. However, this method is not considered viable due to the limitations such as retention at the unfavorable conditions, weak stability in the presence of divalent ions, high cost and its inability to work under high temperature-high salinity conditions. For that reason, this paper will evaluate the proper conditions and criteria for the successful implementation of polymer flooding. Four different partially hydrolyzed polyacrylamide (HPAM) based polymers were prepared using standard API procedure for polymer preparation. The effect of concentration and temperature and concentration was evaluated through different rheological measurements. The experimental studies on evaluating the performance and stability of polymers were investigated by performing long-term thermal stability and mechanical degradation tests. Thus, comprehensive rheological studies with partially hydrolyzed polyacrylamide (HPAM) based polymer solutions were designed for defining suitable polymer solution. The preliminary experimental work was carried out at 25-80 °C temperature range and at different concentrations (1000-3000ppm). All four HPAM based polymer solutions showed a typical non-Newtonian rheological characteristic with shear thinning behavior. The obtained results also showed the dependence of the polymer viscosity on the concentration and temperature. As a result, Flopaam 5115 retained and showed the maximum viscosity comparing to other polymer solutions under these conditions. Then, the performance and stability of polymers was tested through different sets of rheological experiments such as long-term thermal stability and mechanical stability tests. In this case, Flopaam 5115 also showed good thermal and mechanical resistance at 80 °C for more than one hundred days and at 23900rpm, respectively. Through the series of different rheological experiments, we identified the most suitable polymer and the conditions that would not disturb the performance and effectiveness of the particular solution. A comprehensive study on the screening different HPAM solutions showed promising results for a future investigation in this direction. The research based on different screening parameters such as concentration, temperature, time, and mechanical exposure was found to be vital for the successful implementation of polymer flooding on a field.
{"title":"A Comprehensive Rheological Characterization of HPAM-Based Polymers for the Potential EOR Implementation","authors":"D. Karimov","doi":"10.2118/204270-stu","DOIUrl":"https://doi.org/10.2118/204270-stu","url":null,"abstract":"\u0000 Polymer flooding is well-established and effective independent technique for improving oil recovery. However, this method is not considered viable due to the limitations such as retention at the unfavorable conditions, weak stability in the presence of divalent ions, high cost and its inability to work under high temperature-high salinity conditions. For that reason, this paper will evaluate the proper conditions and criteria for the successful implementation of polymer flooding.\u0000 Four different partially hydrolyzed polyacrylamide (HPAM) based polymers were prepared using standard API procedure for polymer preparation. The effect of concentration and temperature and concentration was evaluated through different rheological measurements. The experimental studies on evaluating the performance and stability of polymers were investigated by performing long-term thermal stability and mechanical degradation tests. Thus, comprehensive rheological studies with partially hydrolyzed polyacrylamide (HPAM) based polymer solutions were designed for defining suitable polymer solution.\u0000 The preliminary experimental work was carried out at 25-80 °C temperature range and at different concentrations (1000-3000ppm). All four HPAM based polymer solutions showed a typical non-Newtonian rheological characteristic with shear thinning behavior. The obtained results also showed the dependence of the polymer viscosity on the concentration and temperature. As a result, Flopaam 5115 retained and showed the maximum viscosity comparing to other polymer solutions under these conditions. Then, the performance and stability of polymers was tested through different sets of rheological experiments such as long-term thermal stability and mechanical stability tests. In this case, Flopaam 5115 also showed good thermal and mechanical resistance at 80 °C for more than one hundred days and at 23900rpm, respectively.\u0000 Through the series of different rheological experiments, we identified the most suitable polymer and the conditions that would not disturb the performance and effectiveness of the particular solution. A comprehensive study on the screening different HPAM solutions showed promising results for a future investigation in this direction. The research based on different screening parameters such as concentration, temperature, time, and mechanical exposure was found to be vital for the successful implementation of polymer flooding on a field.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126340675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：