Download or read book A Model for Matrix Acidizing of Long Horizontal Well in Carbonate Reservoirs written by Varun Mishra and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Horizontal wells are drilled to achieve improved reservoir coverage, high production rates, and to overcome water coning problems, etc. Many of these wells often produce at rates much below the expected production rates. Low productivity of horizontal wells is attributed to various factors such as drilling induced formation damage, high completion skins, and variable formation properties along the length of the wellbore as in the case of heterogeneous carbonate reservoirs. Matrix acidizing is used to overcome the formation damage by injecting the acid into the carbonate rock to improve well performance. Designing the matrix acidizing treatments for horizontal wells is a challenging task because of the complex process. The estimation of acid distribution along wellbore is required to analyze that the zones needing stimulation are receiving enough acid. It is even more important in cases where the reservoir properties are varying along the length of the wellbore. A model is developed in this study to simulate the placement of injected acid in a long horizontal well and to predict the subsequent effect of the acid in creating wormholes, overcoming damage effects, and stimulating productivity. The model tracks the interface between the acid and the completion fluid in the wellbore, models transient flow in the reservoir during acid injection, considers frictional effects in the tubulars, and predicts the depth of penetration of acid as a function of the acid volume and injection rate at all locations along the completion. A computer program is developed implementing the developed model. The program is used to simulate hypothetical examples of acid placement in a long horizontal section. A real field example of using the model to history match actual treatment data from a North Sea chalk well is demonstrated. The model will help to optimize acid stimulation in horizontal wells.

Download or read book Modeling and Optimization of Matrix Acidizing in Horizontal Wells in Carbonate Reservoirs written by Hậu Trần and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the optimum conditions for wormhole propagation in horizontal well carbonate acidizing was investigated numerically using a horizontal well acidizing simulator. The factors that affect the optimum conditions are rock mineralogy, acid concentration, temperature and acid flux in the formation. The work concentrated on the investigation of the acid flux. Analytical equations for injection rate schedule for different wormhole models. In carbonate acidizing, the existence of the optimum injection rate for wormhole propagation has been confirmed by many researchers for highly reactive acid/rock systems in linear core-flood experiments. There is, however, no reliable technique to translate the laboratory results to the field applications. It has also been observed that for radial flow regime in field acidizing treatments, there is no single value of acid injection rate for the optimum wormhole propagation. In addition, the optimum conditions are more difficult to achieve in matrix acidizing long horizontal wells. Therefore, the most efficient acid stimulation is only achieved with continuously increasing acid injection rates to always maintain the wormhole generation at the tip of the wormhole at its optimum conditions. Examples of acid treatments with the increasing rate schedules were compared to those of the single optimum injection rate and the maximum allowable rate. The comparison study showed that the increasing rate treatments had the longest wormhole penetration and, therefore, the least negative skin factor for the same amount of acid injected into the formations. A parametric study was conducted for the parameters that have the most significant effects on the wormhole propagation conditions such as injected acid volume, horizontal well length, acid concentration, and reservoir heterogeneity. The results showed that the optimum injection rate per unit length increases with increasing injected acid volume. And it was constant for scenarios with different lateral lengths for a given system of rock/ acid and injected volume. The study also indicated that for higher acid concentration the optimum injection rate was lower. It does exist for heterogeneous permeability formations. Field treatment data for horizontal wells in Middle East carbonate reservoirs were also analyzed for the validation of the numerical acidizing simulator. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149428

Download or read book Integrated Method to Evaluate Acid Stimulation of Horizontal Wells in Carbonate Reservoir Through Treatment Pressure Analysis written by Kenji Ueda and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Unlocking a tight carbonate formation for oil and gas production by multi-stage acid stimulation is a relatively cost-effective method as an alternative to propped fracturing for production enhancement. Depending on whether treatment pressure is below or above the formation closure stress, acid stimulation is basically divided into matrix acidizing and acid fracturing. In this study, practical methodology to evaluate both matrix acidizing and acid fracturing through treatment monitoring is presented respectively. For matrix acidizing, monitoring and optimizing a matrix acidizing has been achieved by integrating a forward model used in acidizing design for horizontal wells with a real-time monitoring model for skin evolution during the stimulation. The effect of acidizing is described as an overall skin factor change, and productivity improvement is predicted for the treatment. Then the field treatment data monitored on-site was used to estimate the skin response by treatment injection. History matching procedure of design and actual treatment data will be carried out to update near-wellbore and key wormholing parameters. Through sensitivity study, which parameter should be updated is discussed. Finally optimum rate schedule is identified based on updated parameters. Meanwhile, for acid fracturing treatment, new method for real-time monitoring of acid fracturing, the inverse injectivity vs. superposition time function plot is proposed, subject to the condition that the treatment pressure is above closure pressure after the breakdown. Combining a linear dual-porosity transient slab model with injectivity concept, actual growing cross-sectional area induced by acid fracturing treatment can be monitored in real-time. After production starts, linear flow diagnostic approach with rate-transient analysis provides cross-sectional area flowing from matrix, which is compared with the area induced by acid fracturing during the stimulation. The treatment efficiency provides engineers with additional information as to whether the designed acid fracturing was performed appropriately under the in-situ closure stress field. A field case example of both multi-stage matrix acidizing and acid fracturing acid in horizontal well are also presented respectively in the study to illustrate the application of the approach developed, and to show the value of the integrated approach to monitor and diagnose acid stimulation in horizontal wells. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155416

Download or read book Applied Matrix Acidizing of Carbonate Reservoir written by Ehsan Khamehchi and published by Springer Nature. This book was released on with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Placement Model for Matrix Acidizing of Vertically Extensive Multilayer Gas Reservoirs written by Manabu Nozaki and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Design of matrix acidizing treatments of carbonate formation is still a challenge although extensive research has been done on it. It is necessary to estimate acid distribution along the wellbore. This estimation is very important especially for the case where the reservoir properties vary along the wellbore. This work provides development and application of an apparent skin factor model which accounts for both damage and mobility difference between acid and gas. Combining this model with a conventional acid placement model, we develop an acid placement model for vertically extensive, multilayer gas reservoirs. A computer program is developed implementing the acid placement model. The program is used to simulate hypothetical examples of acid placement for vertically extensive, multilayer gas reservoirs. This model will improve matrix acidizing for gas reservoirs and enable realtime monitoring of acid stimulation more accurately.

Download or read book A Systematic Study of Matrix Acidizing Treatments Using Skin Monitoring Method written by Nimish Pandya and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this work was to evaluate matrix acidizing treatments of vertical and horizontal wells in carbonate reservoirs. Twenty field cases for acidizing treatments were analyzed by evaluating the skin factor evolution from on-site rate/pressure data during the treatment. A skin monitoring method based on the concept of inverse injectivity (Hill and Zhu, 1996) was used to calculate the skin factor evolution. Viscous diversion techniques were analyzed by using the viscous diversion skin model that accounts for viscosity contrast between the reservoir fluid and the injected fluid. The estimated skin evolution during the treatment was validated using the post-treatment well performance. From the post-treatment analysis, it was observed that emulsified acid was not an efficient viscous diverter because only 27% of the wells treated with emulsified acid showed evidence of viscous diversion. Therefore, other viscous diversion techniques are needed to ensure uniform acid coverage. In addition, treatments that involved diversion techniques such as foam, associative-polymers, and viscoelastic surfactants were also evaluated. Thus, the post-treatment evaluation was used to improve and optimize the acid treatment designs. This study was beneficial to diagnose if excess acid volumes were used, or effective diversion was achieved during the acid treatment.

Download or read book Numerical Modeling of Matrix Acidizing in Carbonate and Sandstone Reservoirs written by Wan Wei and published by . This book was released on 2020 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Matrix acidizing is a stimulation technique to improve productivity/injectivity in the near-wellbore region in carbonate and sandstone reservoirs. Carbonate reservoir is heterogeneous in mineralogy, primary porosity, and secondary porosity such as fractures. Optimally through acidizing treatment, wormholes are generated in carbonate reservoirs to improve the permeability and bypass the damaged zone. A two-scale continuum model is implemented in a radial coordinate system to simulate acidizing process in the near-wellbore geometry. The model is extended from single-phase to two-phase by considering mobility change due to water-oil displacement and defining a new criterion for acidizing breakthrough applicable to two-phase flow. The requirement of acid consumption is lower with the existence of oil prior to acidizing treatment. This indicates that for field treatment, maintaining a higher oil saturation can enhance acidizing efficiency. To consider varying mineral compositions in carbonates, the acidizing model is implemented in the UTCOMP-IPhreeqc coupled software to model homogeneous and heterogeneous reactions among acid and minerals. Different acid pore volumes are predicted for limestone, dolostone, and partially dolomitized formation due to the difference in reaction rate and dissolution structures generated. To consider fracture effect in carbonates, the acidizing model in UTCOMP-IPhreeqc is extended to consider reactions on the fracture surface with the aid of EDFM (Embedded Discrete Fracture Model). The fracture with a high conductivity will receive most acid and slow down the wormhole propagation in the matrix. To improve computational efficiency, the acidizing model is also implemented in the semi-parallel version of UTCOMP-IPhreeqc, with the parallelized geochemical calculation. Besides, speedup techniques through defining a tolerance on the relative amount change of geochemical elements to reduce IPhreeqc calls are also applied. Parallel computing saves up to 85% of the total computational time when using 16 processors. And speedup techniques obtain about 50% improvement for the wormhole pattern. The acidizing model in UTCOMP-IPhreeqc is also extended to simulate acidizing process in sandstone reservoirs through modifying IPhreeqc database to include primary and secondary reactions. A largest possible injection rate is recommended to achieve best performance mitigating formation damage caused by precipitation

Download or read book Petroleum Production Systems written by Michael J. Economides and published by Pearson Education. This book was released on 2013 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by four leading experts, this edition thoroughly introduces today's modern principles of petroleum production systems development and operation, considering the combined behaviour of reservoirs, surface equipment, pipeline systems, and storage facilities. The authors address key issues including artificial lift, well diagnosis, matrix stimulation, hydraulic fracturing and sand control. They show how to optimise systems for diverse production schedules using queuing theory, as well as linear and dynamic programming. Throughout, they provide both best practices and rationales, fully illuminating the exploitation of unconventional oil and gas reservoirs. Updates include: Extensive new coverage of hydraulic fracturing, including high permeability fracturing New sand and water management techniques * An all-new chapter on Production Analysis New coverage of digital reservoirs and self-learning techniques New skin correlations and HW flow techniques

Download or read book Selective matrix acidizing of horizontal wells written by Eduardo Ponce Da Motta and published by . This book was released on 1993 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Matrix Acidizing of Heterogeneous Carbonates written by Ryan Keys and published by LAP Lambert Academic Publishing. This book was released on 2011-03-01 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: In matrix acidizing, the goal is to dissolve minerals in the rock to increase well productivity. This is accomplished by injecting an application-specific solution of acid into the formation at a pressure between the pore pressure and fracture pressure. A hydrochloric acid solution is used in carbonate reservoirs, which actually dissolves the calcite rock matrix in the form of conductive channels called wormholes. These wormholes propagate from the wellbore out into the reservoir, bypassing the damaged zone. In matrix acidizing of carbonates, there are four parameters that affect performance: the concentration of calcite present, injection rate of the acid, reaction type, and heterogeneity. Of these parameters, this paper will focus on how rock heterogeneity affects performance. To do this, a coreflood and acidizing apparatus was used to acidize heterogeneous limestone core samples. Rock characterizations and volumetric measurements were considered with the results from these experiments, which made it possible to correlate and quantify the results with rock and volume parameters.

Download or read book Design Set Up and Testing of a Matrix Acidizing Apparatus written by Javier Nevito Gomez and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Well stimulation techniques are applied on a regular basis to enhance productivity and maximize recovery in oil and gas wells. Among these techniques, matrix acidizing is probably the most widely performed job because of its relative low cost, compared to hydraulic fracturing, and suitability to both generate extra production capacity and to restore original productivity in damaged wells. The acidizing process leads to increased economic reserves, improving the ultimate recovery in both sandstone and carbonate reservoirs. Matrix acidizing consists of injecting an acid solution into the formation, at a pressure below the fracture pressure to dissolve some of the minerals present in the rock with the primary objective of removing damage near the wellbore, hence restoring the natural permeability and greatly improving well productivity. Reservoir heterogeneity plays a significant role in the success of acidizing treatments because of its influence on damage removal mechanisms, and is strongly related to dissolution pattern of the matrix. The standard acid treatments are HCl mixtures to dissolve carbonate minerals and HCl-HF formulations to attack those plugging minerals, mainly silicates (clays and feldspars). A matrix acidizing apparatus for conducting linear core flooding was built and the operational procedure for safe, easy, and comprehensive use of the equipment was detailed. It was capable of reproducing different conditions regarding flow rate, pressure, and temperature. Extensive preliminary experiments were carried out on core samples of both Berea sandstone and Cream Chalk carbonate to evaluate the effect of rock heterogeneities and treatment conditions on acidizing mechanisms. The results obtained from the experiments showed that the temperature activates the reaction rate of HF-HCl acid mixtures in sandstone acidizing. The use of higher concentrations of HF, particularly at high temperatures, may cause deconsolidation of the matrix adversely affecting the final stimulation results. It was also seen that the higher the flow rate the better the permeability response, until certain optimal flow rates are reached which appears to be 30 ml/min for Berea sandstone. Highly permeable and macroscopic channels were created when acidizing limestone cores with HCl 15%. In carbonate rocks, there is an optimum acid injection rate at which the dominant wormhole system is formed.

Download or read book Production Enhancement with Acid Stimulation written by Leonard Kalfayan and published by Pennwell Books. This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this new second edition, author Leonard Kalfayan has updated his 2001 book on acid stimulation, one of the primary methods for improving productivity of oil, gas, injection, and disposal wells. A properly designed and executed acid job can improve cash flow. Kalfayan offers practical guidelines for acid treatment design by stressing a systematic approach to candidate selection, treatment design, as well as execution and evaluation for improvement in profits and productivity. The new edition includes discussions of modern acid systems and treatment methods with worldwide applications for both carbonate and sandstone formations; new concepts for simplifying and proliferating sandstone acid application; the latest in carbonate matrix and fracture acidizing; more on non-conventional acidizing concepts and acid systems; and more on geothermal well stimulation. As with his original book, readers can find practical, useful acidizing information and gain greater understanding and appreciate of its benefits.

Download or read book Acid Stimulation written by Carl T. Montgomery and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and up-to-the-minute presentation on acid stimulation technology.

Download or read book Journal of Petroleum Technology written by and published by . This book was released on 1991 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fluid Chemistry Drilling and Completion written by Qiwei Wang and published by Gulf Professional Publishing. This book was released on 2021-11-04 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid Chemistry, Drilling and Completion, the latest release in the Oil and Gas Chemistry Management series that covers all sectors of oil and gas chemicals (from drilling to production, processing, storage and transportation), delivers critical chemical oilfield basics while also covering the latest research developments and practical solutions. Organized by type of chemical, the book allows engineers to fully understand how to effectively control chemistry issues, make sound decisions, and mitigate challenges. Sections cover downhole sampling, crude oil characterization, such as fingerprinting properties, data interpretation, chemicals specific to fluid loss control, and matrix stimulation chemicals. Supported by a list of contributing experts from both academia and industry, the book provides a necessary reference that bridges petroleum chemistry operations from theory, to safer, cost-effective applications. Offers a full range of oil field chemistry issues, including chapters focusing on unconventional reservoirs and water management Helps users gain effective control on problems Includes mitigation strategies from an industry list of experts and contributors Delivers both up-to-date research developments and practical applications, bridging between theory and practice

Download or read book Matrix Acidizing Parallel Core Flooding Apparatus written by Vivek Ghosh and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Matrix acidizing is a well stimulation procedure where acid is injected down the wellbore or coil tubing and into the reservoir near the wellbore region. Wellbore damage is a common issue in the oil field. The primary goal of matrix acidizing in carbonate reservoirs is to bypass wellbore damage by creating highly conductive channels that go several feet into the formation, known as wormholes. The goal of laboratory experiments is to find an optimum injection rate to create dominant wormholes and provide this information to the field. To conduct various experiments, core flooding setups are created. The setup consists of a core holder, accumulator, overburden pump, injection pump, accumulator, pressure sensors, and a back pressure regulator. Results from matrix acidizing core flooding in laboratory conditions provide an understand for wormhole growth, acid diversion, injection rates, and adds a variety of liquid chemicals for testing at reservoir pressures and temperatures. The first objective was to design, assemble, and test a matrix acidizing parallel core flooding apparatus. The apparatus was rated for 5,000 psi and 250 °F. Combinations of the various mechanical components were chosen appropriately to meet the requirements. Electrical wiring and data acquisition hardware was assembled. LabVIEW software code was written for controlling temperature and recording data. The second objective was to create a documented method for conducting experiments. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/150997

Download or read book Reservoir Formation Damage written by Faruk Civan and published by Elsevier. This book was released on 2011-08-30 with total page 1135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reservoir Formation Damage, Second edition is a comprehensive treatise of the theory and modeling of common formation damage problems and is an important guide for research and development, laboratory testing for diagnosis and effective treatment, and tailor-fit- design of optimal strategies for mitigation of reservoir formation damage. The new edition includes field case histories and simulated scenarios demonstrating the consequences of formation damage in petroleum reservoirsFaruk Civan, Ph.D., is an Alumni Chair Professor in the Mewbourne School of Petroleum and Geological Engineering at the University of Oklahoma in Norman. Dr. Civan has received numerous honors and awards, including five distinguished lectureship awards and the 2003 SPE Distinguished Achievement Award for Petroleum Engineering Faculty. Petroleum engineers and managers get critical material on evaluation, prevention, and remediation of formation damage which can save or cost millions in profits from a mechanistic point of view State-of-the-Art knowledge and valuable insights into the nature of processes and operational practices causing formation damage Provides new strategies designed to minimize the impact of and avoid formation damage in petroleum reservoirs with the newest drilling, monitoring, and detection techniques