The Orenburg oil, gas and condensate field (OOGCF) is one of the largest fields in the Volgo-Urals region of Russia. It is characterized by complex formation lithology, underlying water, low bottomhole temperature and significant reservoir depletion making successful matrix acidizing particularly challenging. Existing wellbore equipment prohibits the use of inflatable packers. Therefore only chemical diverters can be used for treatments. Thorough engineering and previous acidizing experience in this region lead teams to select the following technologies to account for all challenges in stimulation on OOGCF: Viscoelastic self-diverting acid (VSDA). Based on viscoelastic surfactant, VSDA initially has low viscosity. However, while the acid spends, the fluid viscosity increases, redirecting flow to less permeable zones. After the treatment, viscous VSDA losses its viscosity when it comes in contact with hydrocarbons and/or solvent pumped in the preflush stage. Absence of polymers in VSDA eliminates risk of formation damage.Selective diverter for temporarily blocking water-producing zones. This water-based fluid with viscoelastic surfactant initially has high viscosity. During matrix acidizing treatment, the selective diverter is injected into all zones. Its viscosity sharply drops in the hydrocarbon-saturated zones while maintaining stability in water-saturated intervals, thus preventing acid injection in undesirable zones.Foam diverter allows foam to be generated in the matrix and temporarily plug the pore spaces. This causes temporary plugging of the acid-etched channels and allows unstimulated zones to be treated. The main advantage of foam diversion is fast and efficient cleanup, which is especially important for depleted formations.Highly retarded emulsified acid helps create wormholes while treating long intervals with low pumping rate through coiled tubing (CT).CT placement with pumping foam diverter through CT and HCl through CT - Tubing annulus simultaneously to block known thief zones. Up to date 3 stimulation treatments were successfully performed with average incremental gas production of 61% that could not be achieved before on this field. A combination of all solutions and technologies mentioned above allowed to address all challenges related to matrix acidizing on OOGCF field.
Historically, coiled tubing (CT) services were positioned as highly tailored services in Russian Federation. Main operations for CT application were post-frac cleanouts (CO) and kick-off (KO) of vertical and slightly deviated wells. Lately, with increasing of horizontal wells quantity, CT application scope became wider: logging, perforating, fishing jobs, CO, milling and other operations. With increasing interest to multi-stage hydraulic fracturing technology, Coiled Tubing application has to grow to meet client demands. In wells with horizontal section 1000 m long, milling of different sizes balls and seats became the most challenging and efficient technical solution. Located in Khanty-Mansiysk District of Western Siberia, Priobskoe field is one of the world’s largest oilfields. Due to low permeability almost 80% of reserves are hardly recoverable. Oilfield development plan include post drill fracturing of all new completed wells. In order to maximize the hydrocarbon recovery field-proven technology enabling multi-stage hydraulic fracturing of an uncemented completion in one pumping treatment became a consistent decision for well treatment. For the first job following workflow was applied: multi-stage hydraulic fracturing completion was installed and 7 zones were fractured one by one. Technology implies that during pumping, at specified stage time, balls are dropped (one at time) from the surface to open the Frac Ports (FP). After the treatment, the most efficient technical solution to remove the balls is to mill them using CT. Following milling operations the well was cleaned out and kicked off with nitrogen. In designing a Coiled Tubing job the critical part is BHA and string selection. Selected mill should be strong enough for milling Frac Port iron and long enough to prevent damage of FP, by side tracking from it to reservoir. As per project program 4 wells have been completed with technology described above. Current production rates show high efficiency of multi-stage hydraulic fracturing technology over traditional well completions. This article describes technical and operational details of the project, candidate selection process, job planning and determines a way to find an optimum technique to meet client demands. Analysis of 4 wells completed with multi-stage fracturing liner is shown in comparison with standard completion in the article.
Измерение забойных параметров в режиме реального времени для повышения эффективности кислотных обработок на месторождении каспийского региона Мансур Аглямов, Данияр Агрынов, Артем Савин, Николай Кулинич, Антон Буров, Общество инженеровнефтяников, Константин Бурдин, Общество инженеров-нефтяников, Шлюмберже Авторское право 2014 г., Общество инженеров нефтегазовой промышленности Этот доклад был подготовлен для презентации на Ежегодной Каспийской технической конференции и выставке SPE, 12 -14 ноября, 2014, Астана, Казахстан.Данный доклад был выбран для проведения презентации Программным комитетом SPE по результатам экспертизы информации, содержащейся в представленном авторами реферате. Экспертиза содержания доклада Обществом инженеров нефтегазовой промышленности не выполнялась, и внесение исправлений и изменений является обязанностью авторов. Материал в том виде, в котором он представлен, не обязательно отражает точку зрения SPE, его должностных лиц или участников. Электронное копирование, распространение или хранение любой части данного доклада без предварительного письменного согласия SPE запрещается. Разрешение на воспроизведение в печатном виде распространяется только на реферат объемом не более 300 слов; при этом копировать иллюстрации не разрешается. Реферат должен содержать явно выраженную ссылку на авторское право SPE.
In the article presented 2 years of experience gained during multi-stage hydraulic fracturing (MSF) on 17 wells, by means of coiled tubing (CT) without lifting it to the surface, performed in years 2017 – 2018 on Vinogradova oilfield, KhMAO, Russia. In 2017 it was successfully implemented innovative technology, where fracturing operations are combined with coiled tubing (CT) operations and are run together with CT inside the well. Current method is based on operating reusable fracturing ports, where opening and closing is carried out using coiled tubing with subsequent performace of MSF along the CT/Tubing annulus. During these jobs, considerable experience was gained, the technologies were optimized and raised issues solved, including excessive abrasive wear of the coiled tubing pipe, leaks, etc. Vinogradova oilfield is a unique oil-saturated low-permeable reservoir with a small effective thickness, characterized by considerable stratification and gas-saturated porous layers. MSF technology demonstrated high efficiency and proved its reliability. Starting from February 2017 till June 2018 it was 17 wells accomplished, where 246 fracturings were carried out. All the wells were successfully commissioned. The implementation of innovative approaches to multi-stage hydraulic fracturing while coiled tubing remains in the well, resulted in 2-fold work time reduction, while the amount of frac ports doubled per well. The time frame of CT work between fracturing stages was minimized from 4 to 1.5 hours. During the job on one of the wells, it was encountered a leak in the completion (liner) in the shoe area, in order to continue MSF job, the isolation packer was run and temporary installed, which allowed to accomplish the operation. The performance of MSF technology without lifting coiled tubing to the surface proved its efficiency and economic feasibility, becoming more and more popular among operating companies, it has great potential for future implementation both in Russia and in the rest of the world. The area of distribution and application of MSF using CT is growing every year, the most relevant technology found in oil fringe with a gas cap or bottom water. The accumulated experience in this project creates the basis for the wide introduction and application of technology on other projects
In 2016, the first application in Russia of a diversion technology with multimodal granules was performed during matrix treatment of a carbonate reservoir in a water-absorbing well in an offshore field in the northern Caspian Sea. The operator's main objectives were the recovery of water-absorbing well injectivity while simultaneously straightening the profile by a temporary isolation of high-absorbing intervals. To achieve the objectives, two operations needed to be performed: large-volume acidizing of J3V Volgian regional stage and acid spotting in the interval of the Neocomian superstage.
The objective of this study was to identify efficiencies and prospects for future implementation of an advanced fracturing system for horizontal wells in which fracturing operations are combined with coiled tubing (CT) operations and are run together with CT inside the well. This results in decreased operation time for multistage fracturing (MSF) jobs. Nowadays, in Western Siberia extensively used following workflow at wells: preoperational work (which include casing drifting, bottom-hole cleaning with sludge trap, coiled tubing slack off for opening a frac-port, pulling the coil out of the hole and following fracturing operation). The method of pumping fracturing operations through the annulus of a CT had been given especially for elimination of extra operationsat wells during jobs at Vinogradova field. The method implemented with a modern completion system that includes special four-way union and protector for coiled tubing and coiled tubing 50.8 mm. The paper contains the analysis of executed MSF jobs with coil tubing inside the well and special equipment which were used in order to implement all the operations during fracturing. The innovative approach to cooperative work between the hydraulic fracturing and CT fleets enabled to reduce the operational timeline by 40% at the first well. As this technology comes into greater use in Russia and abroad, there will need to be sophisticated study and correct implementation. For future success, it will be necessary to perform an in-depth analysis to achieve further reduction in the operating timeline reduction and to eliminate complications in the process.
Today, when most reservoirs have low productivity, the question of whether hydraulic fracturing can be applied to the oil rims becomes very important. During hydraulic fracturing at Novoportovskoe field, the operator was faced with a complex geological model of the reservoir characterized by an absence of strong barriers and minor contrasts in stress between interlayers associated with high risks of breakthrough into the gas zone. An outstanding example of oil rim stimulation and application of new technology was a project in Novoportovskoe field where 30- and 27- stage multistage fracturing operations (MSF) were successfully performed with a shifting ports completion operated by coiled tubing. Currently, oil and gas companies are increasingly demanding technical and technological aspects of the MSF, where the determining factors are the efficiency of operations, the number of stages, the length of the horizontal part of the well, the possibility of refracturing, and ability to open / close sleeves after operation for water and gas shut-off. The experience gained shows the possibilities of modern technologies, where the use of coiled tubing enables meeting the high requirements and also expanding the boundaries of the application. The 30-stage boundary was successfully overcome and allowed to increase the formation coverage by means of more fracturing stages. At the same time, the completion method made it possible to perform MSF without pulling the coiled tubing out of hole and to use all the capabilities and benefits of CT in the case of a screenout (SO). The teamwork between the customer and several of the contractor's product lines enabled successful completion of the integrated project under the difficult geological and climatic conditions of the Novoportovskoe field, which is located beyond the Arctic Circle. An optimized concept of MSF with the use of re-closable full-pass hydraulic fracturing sleeves, operated by a single-trip coiled tubing-conveyed shifting tool was developed and implemented. The following results were achieved: In one week, 57 hydraulic fracturing stages were completed.Hydraulic fracturing stage time was reduced by 63%.The number of stages per well increased by 43%.The gas factor for storage was reduced from that of previous fracturing operations. The integrated method of multi-stage hydraulic fracturing allowed achieving effective fracture coverage to increase the recoverable reserves, while preventing fractures in the gas cap and bottom water. The sliding sleeves MSF technology, operated by coiled tubing without pulling it out of hole, is applicable to further operations in the region and worldwide. This paper describes the experience, lessons learned, and best practices gained at the Novoportovskoe field while deploying a novel application of MSF for oil rim deposits where CT was used as the key enabler. It also describes the first success worldwide in closing of sleeves after 1 year of well production. The well was completed in December 2017 with a 30-stages, and in 2018, after a year of production, logging showed a gas break through which required eight sleeves to be closed. All eight sleeves were successfully closed. This method can be applied to other oil and gas fields, where the construction of horizontal wells with MSF is the main development strategy.
It is becoming more common for operators around the world to use alleged conformance control completions as a means of managing inflow zones and controlling production. When this type of completion is introduced in a field, it is extremely important to analyze its effectiveness at very early stages of the project to achieve maximized zonal contribution together with proper compartmentalization in current and subsequent completions, since this will have a significant impact on the future life of the entire field. A thorough analysis should include understanding zonal isolation before and after acid stimulation, fluid distribution inside the compartments during the treatment, and confirmation of completion integrity. Analyzing completion performance by introducing additional downhole monitoring systems or devices is costly and is more appropriate for the long term. Another option, surveillance with wireline technology, may not provide definite conclusions due to limited acquisition extent. Alternatively, coiled tubing (CT) can provide a fit-for-purpose integrated solution to data acquisition and analysis challenge. The proposed approach uses distributed temperature sensing technology along with real-time data streaming capabilities to provide an instantaneous insight on wellbore dynamics, thus enabling informed decisions on treatment optimization, as well as yielding reliable information on interzonal communication. This study is based on a success story of intervening with CT on 10 wells, with a total of 40 compartments in a carbonate reservoir in the Caspian region. Distributed temperature evolution models are used to build a signature library characteristic of specific flow events in the wellbore. The study consists of distributed temperature surveys lasting from 30 minutes to 6 hours that were acquired before and during the acid stimulation of each conformance compartment. Unique temperature features are identified in specific flow events, such as communication between compartments, loss of completion integrity, and effective stimulated area determination, to name a few. Those events are hypothesized and corroborated using downhole point measurements. A significant finding is that communication between zones occurs through several possible paths (i.e., through the formation/matrix or via the completion). The stimulation strategy can be modified accordingly, leveraging downhole data to maximize completion efficiency. This combination of transient distributed temperature and point measurement data provides an insight into wellbore and reservoir flow dynamics and facilitates an optimized stimulation strategy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.