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Collaborating Authors
Santa Maria Basin
Decreasing Asphaltene Precipitation and Deposition during Immiscible Gas Injection Via the Introduction of a CO2-Soluble Asphaltene Inhibitor
Gandomkar, Asghar (Department of Chemical and Petroleum Engineering, Faculty of Engineering, Shiraz Branch, Islamic Azad University (Corresponding author)) | Torabi, Farshid (Faculty of Engineering and Applied Science, University of Regina) | Nasriani, Hamid Reza (School of Engineering, Faculty of Science and Technology, University of Central Lancashire) | Enick, Robert M. (Department of Chemical and Petroleum Engineering, University of Pittsburgh)
Summary In this study, the ability of dilute concentrations of toluene to act as a CO2-soluble asphaltene stabilization agent capable of inhibiting asphaltene precipitation during immiscible CO2 injection was assessed. Phase behavior results indicated that 1,000 to 20,000 ppm toluene could readily dissolve in CO2 at cloudpoint pressures that are well below the formation pressure and typical CO2 minimum miscibility pressure (MMP) values during gas-based enhanced oil recovery (EOR). Single-phase solutions of the modified gas (CO2/toluene) were then combined with asphaltenic oils in oil swelling phase behavior tests to demonstrate that the presence of toluene increased the amount of CO2 that dissolved into reservoir crude oil at a specified temperature and pressure. However, asphaltene precipitation diminished, apparently because the effect of the increased asphaltene solvent strength of toluene was more significant than the increased amount of CO2 (an asphaltene antisolvent) that entered the oil-rich phase. During the injection of CO2/toluene solution into cores initially saturated with crude oil and brine, compared to the injection of pure CO2, asphaltene deposition declined during the injection of CO2/toluene mixtures for asphaltenic volatile and intermediate oils from 3.7 wt% to 0.7 wt% and 5.9 wt% to 1.7 wt%, respectively. Based on the asphaltene particle-size analysis, the CO2/toluene mixtures can stabilize oil particles and simultaneously reduce asphaltene aggregation more effectively than pure CO2.
- South America (0.93)
- North America > United States > Oklahoma (0.28)
- Asia > Middle East > Kuwait (0.28)
- Africa > Middle East > Algeria (0.28)
- Geology > Mineral (1.00)
- Geology > Rock Type > Sedimentary Rock (0.47)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- South America > Venezuela > Lake Maracaibo > Maracaibo Basin > Lake Maracaibo Field (0.99)
- North America > United States > California > Santa Maria Basin > Ventura Avenue Field (0.99)
- Europe > Greece > Prinos Field (0.99)
- (8 more...)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene (1.00)
- Facilities Design, Construction and Operation > Flow Assurance > Precipitates (paraffin, asphaltenes, etc.) (1.00)
Plunger lift has become a widely accepted and economical artificial lift alternative, especially in high-gas/liquid-ratio (GLR) gas and oil wells (Figure 1). Plunger lift uses a free piston that travels up and down in the well's tubing string. It minimizes liquid fallback and uses the well's energy more efficiently than does slug or bubble flow. As with other artificial lift methods, the purpose of plunger lift is to remove liquids from the wellbore so that the well can be produced at the lowest bottomhole pressures. Figure 1--Plunger installed in Canada. In recent years, the advent of microprocessors and electronic controllers,[1][2] [3][4] the studies detailing the importance of plunger seal and velocity,[5] and an increased focus on gas production have led to a much wider use and broader application of plunger lift. Microprocessors and electronic controllers have increased the reliability of plunger lift.[1][2][4]
- North America > United States > New Mexico > San Juan Basin (0.99)
- North America > United States > Colorado > San Juan Basin (0.99)
- North America > United States > California > Santa Maria Basin > Ventura Avenue Field (0.99)
- North America > United States > Arizona > San Juan Basin (0.99)
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)
ABSTRACT: Knowledge of the in situ stress state is critical for underground rock engineering projects, but direct measurement data are often not available. Although borehole breakouts are only indicative of the in situ stress state, they nevertheless represent a significant data resource. Properties such as breakout orientation, width and depth can all potentially be used to constrain the in situ stress state. In this paper, we present a novel global optimization and associated objective function that uses breakout data to constrain the normalized in situ stress tensor. This tensor is one in which the magnitudes of the three principal stresses are normalized with respect to the difference between the maximum and the minimum principal stresses, and three TaitโBryan angles describe the principal stress orientations. The efficacy of the scheme is demonstrated by applying it to breakout data obtained from deep mining operations in the Sudbury mining district of Ontario, Canada. INTRODUCTION In situ stress is necessary information for the design and construction of underground rock engineering projects. Borehole breakouts are stress-induced borehole diametrical elongations that occur when the induced stress exceeds the local rock strength on the borehole wall. These can be identified and are a potential data source to estimate the in situ stress state. Due to the high cost and time-consuming process of direct measurement methods, necessary in situ stress data is often not available in most projects. Given the widespread and increasing use of Acoustic Televiewer (ATV) technology to survey boreholes, large amounts of borehole breakout data are available which are indicative of the in situ stress state. Borehole breakout orientation is widely used to estimate the orientations of horizontal principal stresses (Plumb & Hickman 1985; Zoback et al. 1985), but this requires the assumption that one of the principal stresses is vertical. However, this assumption is not valid in many locales, and breakout data are rarely used to estimate in situ stress magnitudes.
- North America > United States > California > Santa Maria Basin (0.99)
- Asia > Middle East > Syria > Sijan Field (0.98)
Abstract This paper focuses on the effective application of plunger lifts in gas wells with packer completions. Such wells present unique challenges, and the study aims to shed light on the successful use of plunger lift under these conditions. The paper delves into the complexities encountered during operations and emphasizes the opportunities to optimize recovery rates by reducing abandonment thresholds. The study also highlights the key lessons learned throughout the entire process, providing valuable insights to industry professionals working in similar contexts. The deployment of plunger lifts as a project within the current portfolio was undertaken to optimize gas recovery from pre-existing fields. An all-inclusive approach was taken to meticulously determine the wells suitable for potential installation, resulting in 17 such installations. These cases illustrate the obstacles encountered during the installation process and the methodologies employed to surmount them. The efficacy of plunger lift in wells utilizing packers is influenced by several variables, including the need for a high gas-liquid ratio as compared to packer-less completions, sole reliance on tubing energy for plunger cycling, the avoidance of severe slugging flow regimes, and the lack of casing pressure monitoring. Following initial trials in 2021 and 2022, a total of 17 plunger systems were installed, yielding highly favorable outcomes in terms of production resurgence, amounting to approximately 5-6 MMCFD from load-up and shut-in wells, coupled with an additional 6.5 BCF of gas and 50 MBC of condensate reserves. Project economics indicate a net present value of approximately 9.7 MM USD, versus a capital expenditure of approximately 1.5 MM USD. The case studies featured in this work underscore the effectiveness of plunger lift systems that utilize packer completions, emphasizing the criticality of precise design and operation of the system for optimal performance. Furthermore, this research outlines several post-installation challenges, including rapid inflow, insufficient energy for plunger cycling, large liquid slugs, and the necessity for plunger lift monitoring and mitigation. Overall, this study offers valuable insights into the design and operation of plunger lift systems in conjunction with packer completions, underscoring the continued requirement for research and innovation in this area to improve gas production in these wells. An innovative aspect of this research is creating selection criteria for packer completions, which underwent further refinement based on insights gleaned from installations. These criteria include DAGLR, velocity profile, flow regime, slug volume, fluid level, and wellbore restrictions. In addition, shut-in pressure trends and plunger arrival data were employed to monitor and optimize plunger lift performance. However, monitoring plungers in packer completions remains an area of study for effectively enhancing plunger lift performance.
- North America > United States (0.68)
- Asia > Middle East > UAE (0.28)
Abstract The authors have been working with the challenges related to decommissioning facilities offshore California since 1996. In a 2018 OTC paper (OTC-28844-MS) they reviewed the challenges for offshore facility decommissioning in this region. This paper reviews and updates the oil and gas platform decommissioning projects being conducted on the federal Outer Continental Shelf (OCS) offshore California and the decommissioning outlook for OCS platforms through the end of this decade. There are a total of 23 oil and gas platforms on the federal OCS offshore California which are submerged lands located more than three nautical miles from the coastline. The authors project that one-third of the 23 OCS platforms and one state water platform are likely to be decommissioned by the end of the decade, and at least 50 percent of the OCS platforms are likely to be removed by the middle of the next decade. Three of the eight OCS platforms being decommissioned, if fully removed, would each establish world water depth records for removing conventional steel platform jackets from the seafloor. The paper also describes the major technical, logistical, environmental, and regulatory challenges operators face in planning and conducting decommissioning projects offshore California.
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Europe > Denmark > North Sea > Danish Sector > Central Graben > Block 5504/6 > Elly Field (0.93)
- South America > Brazil > Parnaiba Basin > Block PN-T-68 > California Field (0.89)
- North America > United States > Kansas > State Field (0.89)
- (2 more...)
Abstract The authors have been working with the challenges related to decommissioning facilities offshore California since 1996. In a 2018 OTC paper (OTC-28844-MS) they reviewed the challenges for offshore facility decommissioning in this region. This paper reviews the oil and gas platform decommissioning projects being conducted on the federal Outer Continental Shelf (OCS) offshore California and the decommissioning outlook for OCS platforms through the end of this decade. There are a total of 23 oil and gas platforms on the federal OCS offshore California which are submerged lands located more than three nautical miles from the coastline. The authors project that one-third of the 23 OCS platforms and one state water platform are likely to be decommissioned by the end of the decade, and at least 50 percent of the OCS platforms are likely to be removed by the middle of the next decade. Three of the eight OCS platforms being decommissioned, if fully removed, would each establish world water depth records for removing conventional steel platform jackets from the seafloor. The paper also describes the major technical, logistical, environmental, and regulatory challenges operators face in planning and conducting decommissioning projects offshore California.
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Europe > Denmark > North Sea > Danish Sector > Central Graben > Block 5504/6 > Elly Field (0.93)
- South America > Brazil > Parnaiba Basin > Block PN-T-68 > California Field (0.89)
- North America > United States > Kansas > State Field (0.89)
- (2 more...)
A Mathematical Modelling of the Plunger Lift Considering Effects of Fluid Friction and Plunger Travel Velocity
Rajvanshi, Saurabh (Oil and Natural Gas Corporation Limited) | Nischal, Rajiv (Oil and Natural Gas Corporation Limited) | Prasad, Bulusu V. R. V (Oil and Natural Gas Corporation Limited) | Yadav, Mahendra Prasad (Oil and Natural Gas Corporation Limited) | Kumar, Avinav (Oil and Natural Gas Corporation Limited) | Gaur, Devendra Pratap (Oil and Natural Gas Corporation Limited) | Sethi, Divyansh (Oil and Natural Gas Corporation Limited) | Sharma, Aman (Oil and Natural Gas Corporation Limited)
Abstract Plunger lift technique is a well-known, widely accepted and economical artificial lift alternative, especially in deliquification of gas wells and to increase the efficiency of intermittently flowing oil wells. This study includes impact of fluid friction losses and variable plunger travel velocity in mathematical modelling of plunger lift design. The design of plunger lift system, in most models, is simulated by a fix value of fluid friction losses based on plunger velocity, which does not consider the variable effects of the friction factor calculation based on Colebrook equation or complex multiphase flow. To consider these effects, other equations must be solved simultaneously with the well-known Foss and Gaul equations. Solution of the plunger lift design equation becomes even more complicated if the fluid friction properties are not uniform. Foss and Gaul suggested an approximation for gas and liquid friction are constant for a given tubing size and a plunger velocity of 1,000 ft/min. Plunger travel velocity is the important parameter in design. The velocity at which the plunger travels up the tubing also affects the plunger efficiency. Very low velocity of plunger increases gas slippage and subsequently lead to inefficient operation. Whereas, high plunger velocities tend to push the plunger through the liquids. A steady state mathematical modelling and sensitivity analysis considering broad estimates, has been done using Python language. This approach can simulate any combination of associated parameters for plunger lift design in a relatively simple and effective manner. The numerical results are compared to the actual available data. Analysis of the numerical results shows that the effects of fluid friction losses and plunger travel velocity are important for accurate modelling and design of the plunger lift system.
- North America > United States (0.28)
- Asia (0.28)
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.48)
Abstract This work highlights the successful application of Gas Wells Deliquification techniques in UEP wells for improving recoveries and optimizing production from wells. Liquid loading is one the major challenge that gas well possess at the end of its life cycle. Gas well load-up is a major production challenge that can result in loss of recovery if not addressed cautiously. Most of the production comes from gas wells that are depleted and subject to liquid loading that leads to pre-mature wells load-up when the gas velocity in the tubing/casing is less than critical velocity. In the continuous effort of production optimization and abandonment pressure reduction for improving recoveries, Gas Wells Deliquification as a project was introduced which included short term and long-term approach of mitigating liquid loading along with competency development. An integrated multi-disciplinary approach was taken to identify candidate wells and phased wise approach of implementing new technologies of soap sticks deployment, plunger lift and coiled tubing gas lift installation. Technology availability is considered as one of the main challenges in the application of these techniques. The results are very positive in bringing back the production from load-up and shut-in wells. Some of the wells have revived back on production and added ~5-8 BCF reserves. During initial assessment of 300+ wells, ~50 wells are potential deliq candidates that can add potentially ~15-17 BCF of reserves with NPV of 7-10 MM$ in next 2-3 years.
- North America > United States (1.00)
- Asia > Indonesia (0.69)
- Oceania > Australia > South Australia > Cooper Basin (0.99)
- Oceania > Australia > Queensland > Cooper Basin (0.99)
- North America > United States > California > Santa Maria Basin > Ventura Avenue Field (0.99)
- Africa > Middle East > Libya > Nalut District > Berkine Basin (Trias/Ghadames Basin) > NC 169A Concession > Wafa Field (0.99)
A matrix-fracture-fluid decoupled PP reflection coefficient approximation for seismic inversion in tilted transversely isotropic media
Huang, Guangtan (Chinese Academy of Sciences) | Ba, Jing (Hohai University) | Gei, Davide (National Institute of Oceanography and Applied Geophysics โ OGS) | Carcione, Josรฉ M. (National Institute of Oceanography and Applied Geophysics โ OGS)
ABSTRACT Fracture-induced azimuthal anisotropy of seismic waves has useful applications in the characterization of hydrocarbon reservoirs as well as the overburden. Existing theories face problems estimating the fracture-weakness parameters, identifying the saturating fluid, and constraining the depth model building. To overcome these problems, we have adopted an azimuthal amplitude variation with angle/offset inversion for the estimation of these parameters and identification of the fluid. First, we define more intuitive fracture and fluid indicators based on rock physics, identifying the fluid by decoupling the fracture weakness parameters. Then, we derive a โrock matrix-fracture-fluidโ decoupled PP-wave reflection coefficient approximation of a weakly tilted transversely isotropic medium by using a perturbation matrix and scattering theory. Compared with the conventional fracture weakness-based approximation, our method incorporates the fracture density and the fluid indicator. The inversion test finds that our approximation is effective.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.69)
- North America > United States > California > Santa Maria Basin > Point Arguello Field (0.99)
- Asia > China > Xinjiang Uyghur Autonomous Region > Tarim Basin (0.99)
Abstract The fall and upstroke characteristics of bypass plunger are investigated for conventional and continuous flow plunger lift operations using experimental and field data. The bypass plunger's operational boundaries are compared with those of two-piece plungers. Clutch failure is also evaluated. Bypass and two-piece plungers were tested in static and dynamic conditions to compare their fall drag characteristics with two different tubing and plunger sizes. Casing pressure buildup was used to surface the bypass plunger to represent the conventional plunger lift type of operation for the upstroke tests. Continuous gas and liquid injection were used to achieve multiphase flow conditions for bypass plunger experiments. Experimental findings retrieved from the study were combined with mechanistic models to predict fall and upstroke stages of the bypass plunger in the field conditions. Multiphase flow simulator results were presented, and its effect on plunger lift mechanistic models were discussed. In the static facility, bypass plungers were found to have a higher drag coefficient, falling slower than sleeves of the same height. The drag coefficient values for 1.9-in OD and 2.34-in OD bypass and sleeves were similar, suggesting that plungers tested for a given tubing size can be extrapolated to others. The bypass plunger was suitable for conventional and continuous flow plunger lift operations. The 19.5-in bypass plunger and 9-in sleeve fall and upstroke velocities were analogous. Visual observations showed that the bypass plunger clutch mechanism may not get fully opened if the plunger does not hit the lubricator fast enough. The well test, high-frequency pressure, and plunger lift data of five wells from the Permian basin were analyzed. The continuous flow plunger-lift mechanistic models are used to estimate the bypass plunger cycle. The total cycle time and plunger run per day estimations matched with average run-time and trip-count field data. The study presents the bypass plunger lift's cycle mechanics, operational limitations, and comparison with two-piece plungers in different tubing sizes. The experimental and field data of bypass plungers, mechanistic model benchmarking, and potential bypass plunger lift applications are featured.
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (25 more...)