Download or read book Decline Curve Analysis in Shale Gas Wells written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Production Decline Analysis and Application written by Hedong Sun and published by Gulf Professional Publishing. This book was released on 2015-02-12 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, production decline-curve analysis has become the most widely used tool in the industry for oil and gas reservoir production analysis. However, most curve analysis is done by computer today, promoting a "black-box" approach to engineering and leaving engineers with little background in the fundamentals of decline analysis. Advanced Production Decline Analysis and Application starts from the basic concept of advanced production decline analysis, and thoroughly discusses several decline methods, such as Arps, Fetkovich, Blasingame, Agarwal-Gardner, NPI, transient, long linear flow, and FMB. A practical systematic introduction to each method helps the reservoir engineer understand the physical and mathematical models, solve the type curves and match up analysis, analyze the processes and examples, and reconstruct all the examples by hand, giving way to master the fundamentals behind the software. An appendix explains the nomenclature and major equations, and as an added bonus, online computer programs are available for download. - Understand the most comprehensive and current list of decline methods, including Arps, Fetkovich, Blasingame, and Agarwal-Gardner - Gain expert knowledge with principles, processes, real-world cases and field examples - Includes online downloadable computer programs on Blasingame decline type curves and normalized pseudo-pressure of gas wells

Download or read book A Study of Decline Curve Analysis in the Elm Coulee Field written by Seth C Harris and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last two years, due in part to the collapse of natural gas prices, the oil industry has turned its focus from shale gas exploration to shale oil/tight oil. Some of the important plays under development include the Bakken, Eagle Ford, and Niobrara. New decline curve methods have been developed to replace the standard Arps model for use in shale gas wells, but much less study has been done to verify the accuracy of these methods in shale oil wells. The examples that I investigated were Arps with a 5% minimum decline rate as well as the stretched exponential model (SEPD) and the Duong method. There is a great amount of uncertainty about how to calculate reserves in shale reservoirs with long multi-fractured horizontals, since these wells have not yet been produced to abandonment. Although the Arps model can reliably describe conventional reservoir production decline, it is still uncertain which empirical decline curve method best describes a shale oil well to get a rapid assessment of expected recovery. My focus began in the oil window of the Eagle Ford, but I ultimately chose to study the Elm Coulee field (Bakken formation) instead to see what lessons an older tight oil play could lend to newer plays such as the Eagle Ford. Contrary to existing literature, I have found evidence from diagnostic plots that many horizontal wells in the Elm Coulee that began producing in 2006 and 2007 have entered boundary-dominated flow. In order to accommodate boundary flow I have modified the Duong and SEPD methods such that once boundary-dominated flow begins the decline is described by an Arps curve with a b-value of 0.3. What I found from hindcasting was that early production history, up to six months, is generally detrimental to accurate forecasting in the Elm Coulee. This was particularly true for the Arps with 5% minimum decline or the Duong method. Early production history often contains apparent bilinear flow or no discernible trend. There are many possible reasons for this, particularly the rapid decrease in bottomhole pressure and production of fracture fluid. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151644

Download or read book COMBINING DECLINE CURVE ANALYSIS AND GEOSTATISTICS TO FORECAST GAS PRODUCTION IN THE MARCELLUS SHALE written by Zhenke Xi and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditionally, in order to estimate the production potential at a new, prospective field site via simulation or material balance, one needs to collect various forms of expensive field data and/or make assumptions about the nature of the formation at that site. Decline curve analysis would not be applicable in this scenario, as producing wells need to pre-exist in the target field. The objective of our work is to make first-order forecasts of production rates at prospective, undrilled sites using only production data from existing wells in the entire play. This is accomplished through co-kriging of decline curve parameter values, where the parameter values are obtained at each existing well by fitting an appropriate decline model to the production history. Co-kriging gives the best linear unbiased prediction of parameter values at undrilled locations, and also estimates uncertainty in those predictions. Thus, we can obtain production forecasts at P10, P50, and P90, as well as calculate EUR at those same levels, across the spatial domain of the play.To demonstrate the proposed methodology, we use monthly gas flow rates and well locations from the Marcellus shale gas play in this research. Looking only at horizontal and directional wells, the gas production rates at each well are carefully filtered and screened. Also, we normalize the rates by perforation interval length. We keep only production histories of 24 months or longer in duration to ensure good decline curve fits. Ultimately, we are left with 5,637 production records. Here, we choose Duongs decline model to represent production decline in this shale gas play, and fitting of this decline curve is accomplished through ordinary least square regression.Interpolation is done by universal co-kriging with consideration to correlation between the four parameters in Duongs model, which also show linear trends (the parameters show dependency on the x and y spatial coordinates). Kriging gives us the optimal decline curve coefficients at new locations (P50 curve), as well as the variance in these coefficient estimates (used to establish P10 and P90 curves). We are also able to map EUR for 25 years across the study area. Finally, the universal co-kriging model is cross-validated with a leave-one-out scheme, which shows significant but not unreasonable error in decline curve coefficient prediction. The methods proposed are easy to implement and do not require various expensive data like permeability, bottom hole pressure, etc., giving operators a risk-based analysis of prospective sites. While we demonstrate the procedure on the Marcellus shale gas play, it is applicable to any play with existing producing wells. We also make this analysis available to the public in a user-friendly web app.

Download or read book Comparison of Emperical Decline Curve Analysis for Shale Wells written by Mohammed Sami A. Kanfar and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study compares four recently developed decline curve methods and the traditional Arps or Fetkovich approach. The four methods which are empirically formulated for shale and tight gas wells are: 1. Power Law Exponential Decline (PLE). 2. Stretched Exponential Decline (SEPD). 3. Duong Method. 4. Logistic Growth Model (LGM). Each method has different tuning parameters and equation forms. The main objective of this work is to determine the best method(s) in terms of Estimated Ultimate Recovery (EUR) accuracy, goodness of fit, and ease of matching. In addition, these methods are compared against each other at different production times in order to understand the effect of production time on forecasts. As a part of validation process, all methods are benchmarked against simulation. This study compares the decline methods to four simulation cases which represent the common shale declines observed in the field. Shale wells, which are completed with horizontal wells and multiple traverse highly-conductive hydraulic fractures, exhibit long transient linear flow. Based on certain models, linear flow is preceded by bilinear flow if natural fractures are present. In addition to this, linear flow is succeeded by Boundary Dominated Flow (BDF) decline when pressure wave reaches boundary. This means four declines are possible, hence four simulation cases are required for comparison. To facilitate automatic data fitting, a non-linear regression program was developed using excel VBA. The program optimizes the Least-Square (LS) objective function to find the best fit. The used optimization algorithm is the Levenberg-Marquardt Algorithm (LMA) and it is used because of its robustness and ease of use. This work shows that all methods forecast different EURs and some fit certain simulation cases better than others. In addition, no method can forecast EUR accurately without reaching BDF. Using this work, engineers can choose the best method to forecast EUR after identifying the simulation case that is most analogous to their field wells. The VBA program and the matching procedure presented here can help engineers automate these methods into their forecasting sheets. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151124

Download or read book Better Understanding of Production Decline in Shale Gas Wells written by Kananek Harongjit and published by . This book was released on 2014 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Production data from the Eagle Ford shale (an analog to the Alaska Shublik shale) was collected from two neighboring counties and analyzed to correlate well performance with completion parameters including length of horizontal wellbore and number of hydraulic fracturing stages. Thirty-eight dry gas wells with production history range of 18-43 months were analyzed using 6 different decline curve analysis (DCA) models including Arps' exponential, harmonic and hyperbolic, power law exponential (PLE), logistic growth analysis (LGA) and Duong's models. In the matching process, 2/3 of history was used to tune the DCA models and their forecasts were compared to the remaining 1/3 of real history. The matching results were analyzed based on production history length and flow regime to have better understanding of limitations and capabilities of each DCA model. Reservoir simulation models, constructed using range of realistic data and actual completion practices of 4 select wells, were employed to assess reasonable values of remaining reserve and remaining well life that were used as benchmarks for comparison with DCA results. The results showed that there was no strong correlation between well performance (average first year production rate) and the horizontal leg or the number of fracturing stages. This was an indication of extremely heterogeneous medium. In most cases, the accuracy of the DCA models increased when longer production history was used to tune the model parameters. LGA seems to be the most accurate DCA model since it gave the highest matching accuracy 71% of the total wells when using longest history length of 31 months. As the flow regime is concerned, LGA model also performed very well matched in 57% of the wells exhibiting only transient flow and 63% for the wells showing transient flow during early production time followed by boundary-dominated flow during late production. Moreover, the remaining reserve and well life of the select wells predicted by LGA fell into reasonably close range of the estimates from the reservoir simulations.

Download or read book Using Decline Curve Analysis Volumetric Analysis and Bayesian Methodology to Quantify Uncertainty in Shale Gas Reserve Estimates written by Raul Alberto Gonzalez Jimenez and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Probabilistic decline curve analysis (PDCA) methods have been developed to quantify uncertainty in production forecasts and reserves estimates. However, the application of PDCA in shale gas reservoirs is relatively new. Limited work has been done on the performance of PDCA methods when the available production data are limited. In addition, PDCA methods have often been coupled with Arp's equations, which might not be the optimum decline curve analysis model (DCA) to use, as new DCA models for shale reservoirs have been developed. Also, decline curve methods are based on production data only and do not by themselves incorporate other types of information, such as volumetric data. My research objective was to integrate volumetric information with PDCA methods and DCA models to reliably quantify the uncertainty in production forecasts from hydraulically fractured horizontal shale gas wells, regardless of the stage of depletion. In this work, hindcasts of multiple DCA models coupled to different probabilistic methods were performed to determine the reliability of the probabilistic DCA methods. In a hindcast, only a portion of the historical data is matched; predictions are made for the remainder of the historical period and compared to the actual historical production. Most of the DCA models were well calibrated visually when used with an appropriate probabilistic method, regardless of the amount of production data available to match. Volumetric assessments, used as prior information, were incorporated to further enhance the calibration of production forecasts and reserves estimates when using the Markov Chain Monte Carlo (MCMC) as the PDCA method and the logistic growth DCA model. The proposed combination of the MCMC PDCA method, the logistic growth DCA model, and use of volumetric data provides an integrated procedure to reliably quantify the uncertainty in production forecasts and reserves estimates in shale gas reservoirs. Reliable quantification of uncertainty should yield more reliable expected values of reserves estimates, as well as more reliable assessment of upside and downside potential. This can be particularly valuable early in the development of a play, because decisions regarding continued development are based to a large degree on production forecasts and reserves estimates for early wells in the play. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148436

Download or read book Shale Analytics written by Shahab D. Mohaghegh and published by Springer. This book was released on 2017-02-09 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the application of modern information technology to reservoir modeling and well management in shale. While covering Shale Analytics, it focuses on reservoir modeling and production management of shale plays, since conventional reservoir and production modeling techniques do not perform well in this environment. Topics covered include tools for analysis, predictive modeling and optimization of production from shale in the presence of massive multi-cluster, multi-stage hydraulic fractures. Given the fact that the physics of storage and fluid flow in shale are not well-understood and well-defined, Shale Analytics avoids making simplifying assumptions and concentrates on facts (Hard Data - Field Measurements) to reach conclusions. Also discussed are important insights into understanding completion practices and re-frac candidate selection and design. The flexibility and power of the technique is demonstrated in numerous real-world situations.

Download or read book Production Optimization and Forecasting of Shale Gas Wells Using Simulation Models and Decline Curve Analysis written by Peter O. Ikewun and published by . This book was released on 2012 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Production data from the Eagle Ford shale (an analogue to the Shublik shale of Alaska) was compiled from three neighboring counties and analyzed using decline curve analysis (DCA) to correlate production performance with completion method (horizontal leg/stages of fracture) and length of horizontal leg. Generic simulation models were built and run using a realistic range of properties. Simulation results provided a better understanding of interplay between static properties and dynamic behavior. Results from the DCA of 24 producing wells with production histories of 9-57 months showed, for most cases, an increase in reserves with more fracture stages. However, the DCA generated different forecasts depending on which part of the data were used. This clearly indicated the need for running simulations. Simulation runs can generate more reliable production forecast of which the decline part can be used to evaluate the capability of DCA to reproduce the production profiles. A combination of simulation models and DCA was used to optimize production and forecasting. Simulation models were used to optimize production for a range of different reservoir and completion parameters. The ability for DCA to reproduce simulated results (built with similar data from the Eagle Ford) for wells with different production periods was also analyzed. This results in better and more reliable production forecasts for the Eagle Ford and other young producing shale reservoirs possessing short production history. Modeling of the complex reservoir geometry and fracture networks of these types of reservoirs would give an extensive understanding of the flow mechanics.

Download or read book Sustainable Natural Gas Reservoir and Production Engineering written by David Wood and published by Gulf Professional Publishing. This book was released on 2021-10-30 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable Natural Gas Reservoir and Production Engineering, the latest release in The Fundamentals and Sustainable Advances in Natural Gas Science and Engineering series, delivers many of the scientific fundamentals needed in the natural gas industry, including improving gas recovery, simulation processes for fracturing methods, and methods for optimizing production strategies. Advanced research covered includes machine learning applications, gas fracturing mechanics aimed at reducing environmental impact, and enhanced oil recovery technologies aimed at capturing carbon dioxide. Supported by corporate and academic contributors along with two well-distinguished editors, this book provides today's natural gas engineers the fundamentals and advances in a convenient resource - Helps readers advance from basic equations used in conventional gas reservoirs - Presents structured case studies to illustrate how new principles can be applied in practical situations - Covers advanced topics, including machine learning applications to optimize predictions, controls and improve knowledge-based applications - Helps accelerate emission reductions by teaching gas fracturing mechanics with an aim of reducing environmental impacts and developing enhanced oil recovery technologies that capture carbon dioxide

Download or read book Unconventional Reservoir Geomechanics written by Mark D. Zoback and published by Cambridge University Press. This book was released on 2019-05-16 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive overview of the key geologic, geomechanical and engineering principles that govern the development of unconventional oil and gas reservoirs. Covering hydrocarbon-bearing formations, horizontal drilling, reservoir seismology and environmental impacts, this is an invaluable resource for geologists, geophysicists and reservoir engineers.

Download or read book Hydraulic Fracturing in Unconventional Reservoirs written by Hoss Belyadi and published by Gulf Professional Publishing. This book was released on 2019-06-18 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic Fracturing in Unconventional Reservoirs: Theories, Operations, and Economic Analysis, Second Edition, presents the latest operations and applications in all facets of fracturing. Enhanced to include today's newest technologies, such as machine learning and the monitoring of field performance using pressure and rate transient analysis, this reference gives engineers the full spectrum of information needed to run unconventional field developments. Covering key aspects, including fracture clean-up, expanded material on refracturing, and a discussion on economic analysis in unconventional reservoirs, this book keeps today's petroleum engineers updated on the critical aspects of unconventional activity. - Helps readers understand drilling and production technology and operations in shale gas through real-field examples - Covers various topics on fractured wells and the exploitation of unconventional hydrocarbons in one complete reference - Presents the latest operations and applications in all facets of fracturing

Download or read book Analysis of Production Decline Curves written by Steven W. Poston and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the production characteristics and associated interpretation analyses of petroleum reservoirs in a complete, thorough, and consistent manner.

Download or read book Decline Curve Analysis of Tight Sand Shale Gas Reservoirs written by 林柏廷 and published by . This book was released on 2014 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Using Decline Map Anlaysis DMA to Test Well Completion Influence on Gas Production Decline Curves in Barnett Shale Denton Wise and Tarrant Counties written by Ibrahim Alkassim and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing interest and focus on unconventional reservoirs is a result of the industry's direction toward exploring alternative energy sources. It is due to the fact that conventional reservoirs are being depleted at a fast pace. Shale gas reservoirs are a very favorable type of energy sources due to their low cost and long-lasting gas supply. In general, according to Ausubel (1996), natural gas serves as a transition stage to move from the current oil-based energy sources to future more stable and environment-friendly ones. By looking through production history in the U.S Historical Production Database, HPDI (2009), we learn that the Barnett Shale reservoir in Newark East Field has been producing since the early 90's and contributing a fraction of the U.S daily gas production. Zhao et al. (2007) estimated the Barnett Shale to be producing 1.97 Bcf/day of gas in 2007. It is considered the most productive unconventional gas shale reservoir in Texas. By 2004 and in terms of annual gas production volume, Pollastro (2007) considered the Barnett Shale as the second largest unconventional gas reservoir in the United States. Many studies have been conducted to understand better the production controls in Barnett Shale. However, this giant shale gas reservoir is still ambiguous. Some parts of this puzzle are still missing. It is not fully clear what makes the Barnett well produce high or low amounts of gas. Barnett operating companies are still trying to answer these questions. This study adds to the Barnett chain of studies. It tests the effects of the following on Barnett gas production in the core area (Denton, Wise, and Tarrant counties): * Barnett gross thickness, including the Forestburg formation that divides Barnett Shale. * Perforation footage. * Perforated zones of Barnett Shale. Instead of testing these parameters on each well production decline curve individually, this study uses a new technique to simplify this process. Decline Map Analysis (DMA) is introduced to measure the effects of these parameters on all production decline curves at the same time. Through this study, Barnett gross thickness and perforation footage are found not to have any definite effects on Barnett gas production. However, zone 3 (Top of Lower Barnett) and zone 1 (Bottom of Lower Barnett) are found to contribute to cumulative production. Zone 2 (Middle of Lower Barnett) and zone 4 (Upper Barnett), on the other hand, did not show any correlation or influence on production through their thicknesses.

Download or read book A Well Performance Study of Eagle Ford Shale Gas Wells Integrating Empirical Time Rate and Analytical Time Rate Pressure Analysis written by Avery Sutton Davis and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, our purpose is to create a "performance-based reservoir characterization" using production data (measured rates and pressures) from a selected gas condensate region within the Eagle Ford Shale (S. Texas). We use modern time-rate ("decline curve") analysis and time-rate-pressure ("model-based") analysis methods to analyze/interpret/diagnose gas condensate well production data. We estimate reservoir and completion properties - specifically: formation permeability, fracture-face skin effect, fracture half-length, and fracture conductivity. We correlate these results with known completion variables - specifically: completed lateral length, total proppant, total water used, and type of hydraulic fracturing fluid. We use the time-rate and time-rate-pressure analyses to forecast future production and to estimate ultimate recovery. Finally, we apply pressure transient analysis methods to those cases where the production history contains shut-in periods of sufficient duration to provide resolution in the pressure build-up data to identify reservoir features and qualitatively validate completion effectiveness. It is noted that ONLY surface pressures are available for the wells considered in this study. We utilize industry-standard software to perform single well rate-time "decline curve" analyses. The traditional "modified-hyperbolic" time-rate model was used as the "basis" relation and the "power-law exponential" time-rate model was used as a check/validation (the power-law exponential model tends to be a more conservative relation for generating forecasts and estimating ultimate recovery). We also utilize industry-standard software to perform single well time-rate-pressure "model-based" analyses --- this methodology is also known as Rate Transient Analysis (RTA). In this work we used the full analytical model for the performance of a Multi-Fracture Horizontal Well (as opposed to a proxy or numerical model). We use Microsoft Excel and a commercial statistical software package to correlate the production analysis results with the measured completion parameters to create "design" relations for well completions - specifically correlations of estimated ultimate recovery with completion variables (completed lateral length, total proppant, total water used, and type of hydraulic fracturing fluid). Finally, we utilize industry-standard software to perform pressure transient analysis on the cases where the quality and relevance of the shut-in pressure data warranted such analyses. In this work, we "cross-validate" the estimated ultimate recovery results by comparison of the time-rate and time-rate-pressure analysis results. The correlation of EUR with completion variables, we propose, is shown to be statistically relevant for almost all combinations of variables, and the correlation relation should be applicable for creating completion designs. The analysis of surface-derived pressure transient data is successfully demonstrated for several cases taken from the gas condensate region of the Eagle Ford Shale (S. Texas). The work we perform in this thesis clearly demonstrates the validity of using empirical (time-rate) and analytical (time-rate-pressure) analysis methods for the purpose of characterizing well performance for wells in the gas condensate region of the Eagle Ford Shale (S. Texas). The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155432

Download or read book Stretched Exponential Decline Model as a Probabilistic and Deterministic Tool for Production Forecasting and Reserve Estimation in Oil and Gas Shales written by Babak Akbarnejad Nesheli and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Today everyone seems to agree that ultra-low permeability and shale reservoirs have become the potentials to transform North America's oil and gas industry to a new phase. Unfortunately, transient flow is of long duration (perhaps life of the well) in ultra-low permeability reservoirs, and traditional decline curve analysis (DCA) models can lead to significantly over-optimistic production forecasts without additional safeguards. Stretched Exponential decline model (SEDM) gives considerably more stabilized production forecast than traditional DCA models and in this work it is shown that it produces unchanging EUR forecasts after only two-three years of production data are available in selected reservoirs, notably the Barnett Shale. For an individual well, the SEDM model parameters, can be determined by the method of least squares in various ways, but the inherent nonlinear character of the least squares problem cannot be bypassed. To assure a unique solution to the parameter estimation problem, this work suggests a physics-based regularization approach, based on critical velocity concept. Applied to selected Barnett Shale gas wells, the suggested method leads to reliable and consistent EURs. To further understand the interaction of the different fracture properties on reservoir response and production decline curve behavior, a series of Discrete Fracture Network (DFN) simulations were performed. Results show that at least a 3-layer model is required to reproduce the decline behavior as captured in the published SEDM parameters for Barnett Shale. Further, DFN modeling implies a large number of parameters like fracture density and fracture length are in such a way that their effect can be compensated by the other one. The results of DFN modeling of several Barnett Shale horizontal wells, with numerous fracture stages, showed a very good agreement with the estimated SEDM model for the same wells. Estimation of P90 reserves that meet SEC criteria is required by law for all companies that raise capital in the United States. Estimation of P50 and P10 reserves that meet SPE/WPC/AAPG/SPEE Petroleum Resources Management System (PRMS) criteria is important for internal resource inventories for most companies. In this work a systematic methodology was developed to quantify the range of uncertainty in production forecast using SEDM. This methodology can be used as a probabilistic tool to quantify P90, P50, and P10 reserves and hence might provide one possible way to satisfy the various legal and technical-society-suggested criteria.