Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Abstract With the decreasing price of oil nowadays, the need to develop techniques to reduce operational costs in a field is inevitable. Formation water is a by-product obtained during oil production which is produced is produced in higher quantities than hydrocarbon. This is a major concern for oil and gas industry as separating, treating and reinjecting of the produced water into the reservoir formation requires a large amount of energy, money and time. This paper proposes a new technique for downhole separation of oil and water using a tubular centrifuge which can be integrated of the casing or the tubing string. This centrifugal downhole oil/water separator (CDOWS) will introduce the feed to a large centrifugal force which will separate both fluids based on density differences. The technology is designed for different well configurations satisfying several conditions in the industry. This paper shows and tests the model using Computational fluid dynamics (CFD) study for different designs and configurations. To validate this process in a downhole configuration, a computational fluid dynamics (CFD) study is conducted on a CAD model which was designed using a 3D modeling software. The study investigates the separation efficiency using various diameters, RPMs of the CDOWS as well as different flow rates and water cut. Furthermore, different possible designs are considered in this study. The results are then used to optimize the design of such tool in order to produce a physical model.
- North America > United States (0.46)
- Asia > Middle East (0.28)
- Research Report > New Finding (0.34)
- Overview > Innovation (0.34)
Review and Applicability of Downhole Separation Technology
Muktadir, Golam (Technische Universitรคt Bergakademie Freiberg, Institute of Drilling and Fluid Mining) | Amro, Moh'd M. (Technische Universitรคt Bergakademie Freiberg, Institute of Drilling and Fluid Mining) | Schramm, Andreas (Technische Universitรคt Bergakademie Freiberg, Institute of Drilling and Fluid Mining)
Abstract During the production life of oil reservoir, the water cut gradually increases to high percentage. According to the recent analysis, average worldwide water cut reached 75%. Particularly, water cut in USA is higher than 90%. Most of the produced water is re-injected back into the reservoir as an environmental protection solution as well as to maintain reservoir pressure. Promising new technologies are being advanced to reshape development strategies in petroleum production. Therefore, it is no longer necessary to dedicate wells to only production or injection; now, both functions can be performed within one multipurpose wellbore. Downhole oil-water separation (DOWS) is a propitious solution regarding the largestโvolume waste stream associated with oil and gas production using the multipurpose well concept. After the production of the hydrocarbon from the pay zone, the separation takes place either above the producing zone in the well bore or at the well head. Furthermore, the lighter phase flows to the surface facility and the heavier phase (water) is reinjected below the oil-water contact in the same pay zone. Technologies exist to reduce water-handling volumes at the surface by keeping the water downhole. These include Hydrocyclone separation, Centrifugal & Phase separator, combined gravity and coalescence, Rotary separator, vane-type separators, etc. Although the technology was introduced in 1990's, limited number of trail application is so far installed. Different installations provide critical information on the feasibility and development of DOWS technology. This paper presents the state of the art issues of different separation techniques and designs like Hydrocyclone design, ESP design as well as issues related to verifying separation quality etc. The review summarizes the various papers and reports related to the DOWS technology. Particularly, previous review was written quiet some years earlier and therefore do not include the recent development of different components of the system. The general adoption of the technology is dependent on the understanding of the process and the critical issue solving capacity in the oil and gas industry. As a way forward to the development of the technology, different in-situ options will be suggested considering limitations of the existing systems. Additionally, separation directly in the wellhead has been investigated and dual completion concept is proposed to maximize the efficiency of the system.
- Asia (1.00)
- North America > United States > Texas (0.95)
- Geology > Petroleum Play Type > Unconventional Play > Heavy Oil Play (0.47)
- Geology > Geological Subdiscipline (0.34)
- Asia > China > Heilongjiang > Songliao Basin > Daqing Field > Yian Formation (0.89)
- Asia > China > Heilongjiang > Songliao Basin > Daqing Field > Mingshui Formation (0.89)
- Asia > China > Bohai Bay > Bohai Basin > Jidong Nanpu Field (0.89)
Abstract In recent years, a technique of separating water downhole to reduce the volume of produced water and decrease the chance of surface pollution has been developed. It is called downhole oil-water separation (DOWS) technology. This technique allows water to be separated in the wellbore and injected into a suitable injection zone downhole while oil with traces of water is produced to the surface. Subsequent to the introduction of the DOWS technology to the oil industry in the 1990's, several trial applications have been undertaken to test the technology. These trials allowed significant information to be collected on the feasibility of the DOWS technology. Through the joint efforts of Argonne National Laboratory, CH2M-Hill, and the Nebraska Oil and Gas Conservation Commission, a comprehensive technical report was issued in January 1999 discussing this technology. Additional reports on trial applications and feasibility studies have been presented by various study groups. This paper reviews the status of and issues surrounding the application of downhole separation technology. This review summarizes the various papers and reports dealing with DOWS technology and its application in the oil and gas industry. This technology has the potential to provide significant reductions in produced water as the technology is adopted by the industry. It can also reduce produced water handling costs and increase oil and gas production in the right application. The wide-spread adoption of DOWS technology is dependent on improving the understanding of the process and its applications throughout the oil and gas industry. Introduction One of the waste by-products of crude oil and natural gas production in the upstream industry is produced water. Produced water has been defined as the water produced to the surface from the hydrocarbon bearing formation during the extraction of oil and gas, and can include formation water, injection water and any waste chemicals added downhole or during the oil/water separation processes. Conventional production processes involve producing both oil and water to the surface and then separating them at the surface. This separation occurs through the use of separation and dehydration equipment including skimmer vessels, plate coalescence, hydrocyclones, and, in some cases, cross-flow membrane filters to reduce the oil content in the water phase and enhance the quality of the water prior to disposal. However, as a reservoir matures and oil and gas production peaks, there is often an associated increase in water cut and a corresponding increase in both lifting and water disposal costs. The increased water cut also necessitates additional maintenance for production equipment and downhole treatment for corrosion, bacteria, scale, and naturally occurring radioactive material (NORM). Although producers still have a variety of choices in either disposing the water or re-using it, there is a growing concern from the public related to the handling of this waste product. Public concern about the environmental impacts of produced water disposal has therefore become a major issue in the industry especially related to surface damage due to spillage or subsurface contamination of drinking water due to poor injection activities. Environmental regulations pertaining to produced water management are expected to become more stringent in the future necessitating new practices and techniques of managing produced water. Downhole oil-water separation (DOWS) technology was introduced to the industry in the 1990's and further work to assess its feasibility was sponsored by the US Department of Energy in 1999.[1,2] "DOWS, unlike the conventional separation process, separates oil and gas from produced water at the bottom of the well and injects the separated produced water into another formation usually deeper than the producing formation, while the oil and gas are pumped to the surface."[2]
- North America > United States > Texas (1.00)
- Europe (1.00)
- Water & Waste Management > Water Management > Lifecycle > Disposal/Injection (1.00)
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- North America > United States > Texas > West Gulf Coast Tertiary Basin > Victoria Field (0.99)
- North America > United States > Texas > Fort Worth Basin > Alliance Field > Barnett Shale Formation (0.99)
- Production and Well Operations > Well Operations and Optimization > Produced water management and control (1.00)
- Health, Safety, Environment & Sustainability > Environment > Water use, produced water discharge and disposal (1.00)
- Facilities Design, Construction and Operation > Processing Systems and Design > Separation and treating (1.00)
Abstract Efficient processing of fluids from flowing wells is an important function on a topside facility to maintain optimum hydrocarbon production. Many oil and gas facilities face the additional challenge of limited available footprints to process additional capacity. Normally, onshore facilities move process fluids from the wellhead to a de-sander unit, and then to a 2-phase or 3-phase separator unit. In offshore and onshore production facilities, fluids from multiple wells are sometimes co-mingled in a manifold and processed through two or three separation stages with progressively lower pressures to separate gas, crude oil, and produced water. Sequential pressure letdown and numerous fluid pump-around loops to separator vessels and interconnected piping with pumps, valves, and instrumentation occupy a large space on a wellsite. To add processing flexibility in an ever-changing fluid composition (water cut, gas vapor fraction (GVF), and solids loading) from co-mingled production wells and to remove the bottleneck at the topside processing capacity, a chemically enhanced, smart compact separation system has been developed. The new separation system is based on the centrifugal (CF) separation principle. After comprehensive laboratory testing and Computational Fluid Dynamics (CFD) model validation for separated fluid streams, the system was tested in field conditions at an unconventional wellsite to benchmark mechanical reliability, separation effectiveness, and robustness. The modular design concept of this new system enables operation at 200 to 10,000 bbl/d fluid capacity at nominal increments by adding units in parallel. The system is designed to handle 30 to 99% water cut and normally encountered solids or fines concentrations. This technology is also able to handle ever-changing fluid conditions at the well such as production decline or water cut changes by using a digital interface that controls the separator operation based on inlet fluid conditions. This smart, compact separation system enables efficient separation and reduces the need for over-sized separation vessels. A 2,000 bbl/d, two-phase (oil/water) system has consistently achieved residual oil-in-water (OIW) levels below 400 ppm in the water outlet without chemical addition enhancement. The residence time for separation is less than a minute for the 2,000 bbl/d prototype unit, enabling it to be used as an alternative to a freewater knockout (FWKO) vessel. The prototype unit has a 4-in. diameter housing that is mounted on an 8-feet cast-iron frame with a 15-hp electrical motor coupled as the prime mover. The lab and long-term field test results have also indicated that the CFD simulations can effectively reveal the mechanism of oil-water separation as well as validation of separator sizing parameters for various flow capacities. The refined control algorithms are still in development phase, but when completed they will control the separator dynamically as flow conditions change in the well. A field trial to test chemical demulsifying agents will determine the final separation efficiency of this system.
- North America > United States (0.47)
- Asia (0.46)
Application of Machine Learning to Evaluate the Performances of Various Downhole Centrifugal Separator Types in Oil and Gas Production Systems
Osorio Ojeda, Laura Camila (The University of Oklahoma) | Olubode, Michael (The University of Oklahoma) | Karami, Hamidreza (The University of Oklahoma) | Podio, Tony (Echometer)
Abstract Pumping artificial lift techniques, such as rod pumps and ESPs, are applied for gassy wells more than ever before. This has made the downhole separators a critical part of most such installations. There are multiple categories of downhole separators, with various techniques developed to assess and improve their performances, but no general guidelines are established for their application. This paper aims to classify the separator types and review their performances in the open literature. In addition, various data sets are collected and put together to evaluate and rank downhole centrifugal separators using data analysis and machine learning (ML) techniques. A comprehensive literature review is conducted to collect the available downhole separator performance data. Experiments and Computational Fluid Dynamic (CFD) simulations are the techniques used by the researchers. This information is collected to identify the optimum conditions for each separator type, considering the effects of liquid and gas rates and other flow parameters. The data collected from various research projects over the last 20 years are combined to make a comprehensive downhole separation databank. These data are analyzed using various machine learning algorithms to rank the performances of downhole separators at various operating conditions. Various downhole separators have been tested in the open literature, including poor-boy separators, two-stage separators, packer-type separators, rotary and spiral separators with different designs, etc. A critical factor that adds to the uncertainty is the separator's control system, which significantly affects its efficiency. The available data show that most separators provide separation efficiencies higher than 80% if the downstream casing valve is adequately controlled. The separation efficiencies decline as the liquid and gas rates increase past an upper limit. The collected data from multiple previous studies form a broad dataset. Data analysis is used to compare the performances of different downhole separator classes, and machine learning is applied to identify a robust prediction model. This paper gathers, interconnects, and examines several available research works through data analytics. The results provide a fundamental source and a valuable guideline for downhole liquid-gas separation, particularly in artificial lift applications.
- Production and Well Operations > Well Operations and Optimization > Downhole fluids separation, management and disposal (1.00)
- Facilities Design, Construction and Operation > Processing Systems and Design > Separation and treating (1.00)
- Data Science & Engineering Analytics > Information Management and Systems > Artificial intelligence (1.00)