bluuebunny/crossref_metadata_2025_split huggingface dataset:
Streamline Based Polymerflood Injection Optimization: Experiences in the Mangala Field, India
Authors: Li Ao , Chen Hongquan , Datta-gupta Akhil , Chitale Ashish , Shekher Sunit , Shankar Vivek , Kumar M Suresh , Ahmed Abaan , Das Joyjit , Kumar Ritesh 
Published: September 2022

Abstract
Mangala field (India) is one of the largest polymer flooding fields in the world with hundreds of wells and waxy crude oil. Field-scale optimization of polymer injection is challenging due to the geologic heterogeneity and operational constraints. This paper demonstrates an application of streamline-based injection optimization for the Mangala field. The paper will cover the mathematical foundation, optimization studies, and considerations for field implementation.
Our field application consists of five key stages: i) Problem framing. This includes defining optimization objectives, tuning parameters and constraints such as optimization start/end times, schedule update intervals, field rate targets, and injection/production limits for each well. ii) Rate optimization by streamline method. The optimizer iteratively reallocates the well rates, diverting the injected fluid to high efficiency injector-producer pairs located in upswept oil regions. iii) Optimal schedule interpretation. The rate change, flow pattern alteration and injection efficiency improvement are systematically examined, providing decision makers physical explanations of the suggested rate changes. iv) Selection of key injectors for field implementation. To avoid the risk of large-scale field implementation, limited number of injectors contributing the most to the oil production increase or water production decrease are selected for initial deployment. v) Potential field implementation and validation of the proposed plan based on field observations. Data from offset producers surrounding the rate-reallocated injectors can help evaluate oil production improvement or alleviated decline.
The optimized rate schedule is first compared with the current schedule in the field, honoring the field total liquid injection/production rates. The optimized case redistributes the rate allocation among high efficiency injectors within predefined bottom hole pressure and rate constraints. The cumulative oil production increase for the short-term optimization period, 11 months, is 0.66 MMbbl. The efficiency plots show efficient utilization of injected fluid after optimization and the bubble plots and streamline maps indicate that the optimizer alters the flow pattern for a better sweep of the remaining oil. Based on the full field optimization, 20 key injectors are selected for field implementation. Numerical simulation shows that 75% of total oil gain can be achieved from optimization of the key injectors. For field validation, offset producers are expected to show an arrest in the oil decline rate due to improved pressure support and, also reduced water cut increase after field implementation.
Laboratory Study and Field Application of High Temperature Resistant and Permeable Flooding Nanofluid for Enhanced Spontaneous Imbibition Oil Recovery
Authors: Xiao Lixiao , Hou Jirui , Qu Ming , Wang Weiju , Wen Yuchen , Liang Tuo , Wu Weipeng , Qi Pengpeng 
Published: September 2022

Abstract
Microemulsion with excellent properties has shown significant potential in enhancing oil recovery from tight formations by spontaneous imbibition. High temperature resistant and permeable flooding nanofluid (HTPF-NF) was prepared through microemulsion dilution method. Firstly, an evaluation process of HTPF-NF properties was evaluated through the particle size and high temperature resistant experiments, interfacial tension (IFT) and wettability measurements, as well as the static adsorption experiment. Meanwhile, Transmission Electron Microscope (TEM) was utilized to characterize the particle size and morphology of HTPF-NF before and after solubilization of the crude oil. Optical Microscope (OM) was also used to observe the morphological characteristics of emulsified oil droplets. Then, the spontaneous imbibition oil recovery (SIOR) mechanisms of- HTPF-NF were proposed ulteriorly by adopting imbibition tests and CT scanning technology. Moreover, the field application effects of HTPF-NF micro-fracture huff and puff in Shengli Oilfield were also analyzed. The results show that the optimum concentration of HTPF-NF is 0.2wt% with excellent comprehensive performances. Under this concentration, the particle size is 7.5 nm, the IFT value reaches ultra-low IFT, the wettability alteration ability is remarkable and the adsorption loss is minimized. Afterwards, adhesion work reduction factor (AWRF), solubilization coefficient (SC) and the self-driving force (SDF) are defined and calculated based on the IFT and contact angle for quantitatively analyzing the SIOR mechanisms. Furthermore, the data and images of spontaneous imbibition and CT scanning present that the longer the imbibition distance, the higher SIOR of HTPF-NF. In conclusion, the SIOR mechanisms of HTPF-NF are summarized as follows: remarkable property of solubilizing crude oil, brilliant ability of reducing oil/solid adhesion work by synergistic effect of IFT reduction and wettability alteration, and excellent capability of increasing imbibition distance by larger self-driving force. After soaking for two months, YB well was produced with the dramatic increase of the liquid production from 9.55 bbl/d to 34.5 bbl/d, the oil production from 5.15 bbl/d to 19.1 bbl/d and the water cut from 27.3% to 40.8%.
Onshore and Offshore EOR Applications in Brazil: A Review Study
Authors: Michelett Gustavo , Roberts Autumn , Kalyondo John , Habashi Aiden , Alhafidh Hasan , Hascakir Berna 
Published: September 2022

Abstract
This study reviews the existing oil and gas fields in Brazil located both onshore and offshore. Focus is on geology and production history of Santos, Campos, Reconcavo, Sergipe, and Potiguar Basins. We mainly reviewed the geological and reservoir characteristics of these basins, their production history, applied enhanced oil recovery (EOR) methods, and we finally made some EOR recommendations which may help to increase hydrocarbon recoveries in each basin.
At the beginning of the current decade, Brazil was producing almost 2 MM barrels of oil per day. Nowadays, the pre-salt fields alone (that started operating 15 years ago) produce an average of 1.67 MM bbl/d with a 2.73 MM bbl/d total daily oil production. In other words, the oil production from the basins other than the pre-salt fields started to decline of more than 50% in their production levels.
The divestment of many assets, located both onshore and offshore, opens a window of opportunity and a need for the new owners to apply EOR methods to bring back production to higher levels and recover their investments. By reviewing the data from three onshore fields from Reconcavo, Sergipe, and Potiguar and two offshore fields from the Campos basin, this paper has discussed issues and assessed alternatives that may similarly be applicable to other fields in the same basins. Buracica, Carmopolis, and Canto do Amaro fields presented almost none to low increase in production. One of the reasons may be credited to paraffin wax deposition. To avoid wax deposition and increase oil production, we proposed to combine two methods; a thermochemical method to avoid the buildup of wax with the addition of surfactant to the injected fluid to reduce the interfacial tension between water and oil and increase recovery. Both Jubarte and Marlim have achieved success with waterflooding but currently, a continuous decline is observed. Polymer flooding is proposed as a solution in these cases. The pre-salt fields are still ramping up production at very high rates. Hence, as an alternative, in those reservoirs, CO2-WAG might be applied in the near future before reaching a decline in the oil production.
This study briefly discusses the status of the oil and gas fields in Brazil both located onshore and offshore. Moreover, it provides quick recommendations for the existing problems in Brazil during oil and gas production via EOR methods.
Vaca Muerta Oil Production Facility Energy Efficiency Analysis
Authors: Correnti Augusto , Alzate Daniela , Arze Carolina , Gregorini Sofia , Frete Selene , Heins Andrea , Monzon Cesar , Asis Marcelo 
Published: September 2022

Abstract
Energy efficiency plays an essential role in accelerating clean energy transitions and achieving global climate and sustainable development goals. Global improvements in energy efficiency have been declining since 2015. Energy efficiency along with methane emissions and flaring reduction, is expected to deliver more than 40% of the reduction in energy-related greenhouse gas (GHG) emissions over the next 20 years in the IEA's Sustainable Development Scenario, which shows how to put the world on track to achieve international climate and energy goals in full.
The scope of the analysis focused on the Early Production Facility (EPF) operated by Shell Argentina in Sierras Blancas, which processes the oil and associated gas and water production of Vaca Muerta with an installed capacity of 12,000 bbl/d of crude. The period of analysis considered was from May 2020 to April 2021. Energy consumptions upstream of the processing facility, mainly from the producing wellpads, are out of scope. Within the EPF, the limit defined is the plant operations boundaries, and the scope includes the oil, water and gas processing facilities, lighting, flare, services, and plant office.
The analysis was developed in the frame of the Master on Sustainable Energy Development at ITBA and was based on the methodology required by the standard ISO 50.001 on Energy Management Systems for the energy review1.
The total energy consumption of the plant was measured and compared against the energy usage of the installed equipment. Fuel gas and diesel were identified as the primary energy sources of the plant; however, fuel gas represents more than 90% of the primary energy source of the facility and only 7 pieces of equipment represent more than 90% of the fuel gas consumption.
Both a fuel gas and an electricity balance were performed to validate the inputs of the analysis. Additionally, the energy uses were ranked. Improvement opportunities were identified for the operation and maintenance of the existing facilities, and for the design of future plants or revamps of the existing one. Potential savings of +10% in fuel consumption compared to the baseline were estimated based on previous experiences in analogue facilities2.
This analysis is replicable and scalable to all similar installations, so the methods and criteria used as well as main improvement opportunities identified are shared, with the aim of reducing Scope 1 GHG emissions at country level for upstream operations.
Lost Circulation Material Design for Engineered Fracture Gradient of Drilling
Authors: Nguyen Kien , Mehrabian Amin , Santra Ashok , Phan Dung , Bathija Arpita 
Published: September 2022

Abstract
Lost circulation material (LCM) is known to enhance the breakdown limit of wellbores. However, the related gain in the wellbore circulation density remains a weak link in the literature. A design scheme for the LCM blend is developed in this work that allows for quantification of the maximum enhancement in fracture gradient of wellbores. An analytical solution is developed for this purpose that accounts for wellbore inclination and azimuth. The LCM blend is selected by applying appropriate criteria for the particle size distribution (PSD) to the estimated width of near-wellbore fractures. A constitutive model for stress-strain behavior of the LCM is developed from in-house laboratory data of axial compression test on LCMs. The test is intended to simulate compression of the LCM plug upon partial closure of the fracture faces. The obtained constitutive model is used along with the presented analytical solution to estimate the fracture width, tip stress intensity and the wellbore stress redistribution after fluid filtrate leakoff and closure of fracture faces on the LCM agglomerate. The LCM blend composition is selected by optimizing the resulting variations in the fracture tip stress intensity and wellbore stress enhancement between the pre-leakoff (suspended particle) and post-leakoff (solid agglomerate) states of the deposited particles inside of the fracture. The compromise between fracture tip stress intensity factor and compressional stress redistribution around wellbore wall is shown to determine the extent of enhancement in the wellbore fracture gradient, i.e., the maximum circulation density that would not cause wellbore breakdown. Case studies with fracture gradient gains as large as one lbm/gal are presented.
The Impact of Gas-Oil Miscibility on Oil Recovery During Huff-and-Puff EOR in Organic-Rich Shales
Authors: Cruz Felipe , Mamoudou Sidi , Tinni Ali 
Published: September 2022

Abstract
Injection pressure is a key parameter in the design of a Huff-and-Puff EOR process in organic-rich shales. Reservoir engineering studies have shown that injection pressure and miscibility play a role during Huff-and-Puff EOR. However, during field implementation, the injection pressure is often limited by the number of compressors and in several cases, the gas injected might not reach sufficient pressure to achieve a state of complete miscibility with the oil. These scenarios lead to a condition of partial miscibility or immiscibility which impacts the efficiency of the recovery mechanisms during Huff-and-Puff EOR. The objective of this present study was to quantify experimentally the impact of complete, partial, and immiscible gas injection during Huff-and-Puff EOR in organic-rich shales.
For the purpose of this study, we have collected crude oil and wax preserved core samples from the Eagle Ford shale formation. The Eagle Ford shale samples were characterized by measurements of mineralogy, TOC, porosity, pore throat size, and specific surface area. We performed 20 Huff-and-Puff EOR tests in the shale samples at several different injection pressures, using two field gases and an immiscible helium gas. The minimum miscibility pressure (MMP) between the field gases and the crude oil was measured using the vanishing interfacial tension technique. Oil recovery for each Huff-and-Puff EOR cycle was quantified using NMR measurements. The produced hydrocarbon compositions were determined using a multi-step dry Pyrolysis measurement at the end of each Huff-and-Puff EOR test.
Our results show that injection pressure is one of the most important factors controlling the oil recovery during Huff-and-Puff EOR in shales using a field gas. We observe a strong linear increase in oil recovery as injection pressure increases. The injection of the field gas in either partially miscible or completely miscible conditions provides significantly larger oil recovery compared to the immiscible gas at the same absolute pressures. The oil recovery is three times larger for the field gas in a completely miscible condition compared to the immiscible gas and two times larger in a partially miscible condition. The multi-step dry Pyrolysis results show a preferential production of light hydrocarbon species regardless of the state of miscibility during Huff-and-Puff EOR.
The findings reported in this experimental study will help to optimize the design of field Huff-and-Puff EOR operations in organic-rich shales. The strong linear trend between the injection pressure and the oil recovery factor in the field gas tests can be used for the selection of gas compressors during field implementations. The superior performance of the field gas compared to the immiscible helium gas at the same injection pressures confirms the importance of miscibility during Huff-and-Puff EOR in organic-rich shales.
Experimental Study of Polymer-Alternating-Gas Flood
Authors: Pang Jieqiong , Mohanty Kishore 
Published: September 2022

Abstract
Carbon dioxide (CO2) flooding has a high microscopic displacement efficiency above the minimum miscibility pressure (MMP), but a low sweep efficiency due to gravity segregation and bypassing. In many fields, water-alternating-gas (WAG) is used to improve sweep efficiency, but early breakthrough and low sweep efficiency are common. The objective of this research is to evaluate the performance of polymer-alternating-gas (PAG) floods experimentally in the lab-scale. Continuous gas (CG), WAG and PAG flood experiments were performed in homogeneous and heterogeneous cores. Experiments conducted in homogeneous Berea cores showed that tertiary CG flooding and tertiary WAG flooding had similar incremental oil recovery and the tertiary PAG flooding had a lower incremental oil recovery. Heterogeneous core flood experiments showed that WAG flooding and PAG flooding had similar incremental oil recovery, which were slightly higher than that in the CG flooding. In linear cores, the gravity segregation effect is limited due to the small diameter of cores; so, the extent of bypassing is small. In heterogeneous cores, there is bypassing in CG floods due to permeability contrast and WAG / PAG floods help improve oil recovery. However, PAG oil recovery was no better than WAG oil recovery in these laboratory-scale core floods.
Maximize Reservoir Recovery in a High-Pressure Gas Field Through Re-Evaluating Integrity Of Production Tubulars and Liner Hanger Failure-Based Analysis
Authors: Mohy Amr , Miller Rich A. , El Kholy Sherif , Betancourt Mauricio , Mousa Mohamed 
Published: September 2022

Abstract
A high-pressure gas field in Egypt includes eight development wells drilled and completed: three wells in the West and five wells in the East. The reservoir management team had considered increasing the reservoir recovery by lowering the reservoir abandonment pressure below the initial design value. The eight wells in the field had slightly different production casing ratings and different liner hanger suppliers with different ratings and mechanisms. The impact of lowering the reservoir abandonment pressure had to be checked against all the eight wells in the field in terms of design assumptions and casing/equipment ratings. The main challenge was to lower the reservoir abandonment pressure while maintaining the wells integrity and reliability.
The production packer splits the production pipes into two pressure regimes: above and below the packer. The production pipe section and liner hanger above the production packer will be exposed to the reservoir abandonment pressure in case of communication below and above the packer (e.g., a packer leak near depletion). During the planning phase, the main limiting factor for the reservoir abandonment pressure was the liner hanger in most of the wells. When re-evaluating the potential for a lower abandonment pressure, multiple well barrier elements were considered in their as-installed condition, including pipe collapse, hanger hold-down capacity, and liner top packer differential pressure.
The conclusion of these assessments showed that the weak point was still the liner hanger system in most of the wells, so a further failure-based analysis was conducted on the liner hangers. The results defined an updated reservoir abandonment pressure that maintains well integrity.
This paper outlines the thorough well barrier elements design check and methodology used to support the decision to lower reservoir abandonment pressures and maximize reservoir recovery for the field.
Modeling and Analysis of Hydraulic Fracture Skin and Its Control on Shale Gas Production from Horizontal Wells
Authors: Atama Grace , Akkutlu Ibrahim 
Published: September 2022

Abstract
It is widely recognized that hydraulic fracturing creates a region of altered permeability near the fracture/matrix interface. Although we have a limited understanding, it is believed this region plays an important role on the production rates. The objective of this study is to model the region as a fracture skin explicitly including local physical and chemical phenomena and their associated effects, namely: (1) permeability improvement due to unpropped fracture development during the fracturing, (2) stress increase due to slick water invasion and clay-swelling effect developing after the fracturing, and (3) water-saturation buildup due to capillary end effect (CEE) developing during the flowback and production. A sensitivity analysis on the derived skin indicates key parameters controlling production and help in minimizing the damage.
The proposed fracture skin increases at a decreasing rate with distance away from the fracture/matrix interface, which mirrors the invaded fracturing fluid (slick-water) near the interface. The sensitivity analysis performed shows that clay swelling is the predominant damage mechanism and is controlled by the geo-mechanical parameters of the permeability model: (i) the normalized effective stress at the fracture matrix/interface when clay swelling develops in the altered zone, and (ii) strength of the unpropped fractures and cracks inside the damage zone to stay open. On the other hand, the contribution of CEE to the skin is mainly controlled by the average water saturation in the damaged zone. CEE can thus be severe in formations with high water saturation. To minimize the damage, the salinity of the injected water needs to be increased, which in turn will reduce the chemical imbalance between the clay-bound water and slick-water, preventing osmosis. In addition, using proppants with a wider particle size distribution could reduce the damage by allowing smaller size proppants to invade into secondary fractures and cracks, hence, keeping them propped open during the production.
Drillpipe Conveyed Cased Hole Logging: New Technology and Mode of Conveyance for Cement and Casing Inspection
Authors: Hawthorn Andy , Steinsiek Roger , Rahman Shaela 
Published: September 2022

Abstract
Casing and cement are probably the two most critical components for good well integrity through the life of a well. Understnding the condition and annular coverage of both is essential for many subsequent operations and may also, in many locations, be a regulatory requirement. Therefore, a good knowledge is needed of the internal dimensions of the casing, the ovality, the thickness of the casing, the level of corrosion or wear, and the material in the annular space behind the casing. As the industry moves towards a significant amount of mature fields there is a push towards accessing new reservoir exposure from within existing production infrastructure. This is leading to a significant increase in the number of re-entered wells, often in highly deviated wellbores. Sidetracking off an existing cased well requires a good understanding of the condition of the casing and cement. It is now often the case that casing and cement evaluation operations are required several times on the same well. Historically these measurements have only been available on wireline. What we shall describe in this paper is the development and early field results of a pipe conveyed equivalent. The best description of this is to consider it the analog of a logging while drilling tool, but specifically designed for cased hole interpretation and furthermore for casing inspection and cement mapping. The fact that we run drillpipe in the well on numerous occasions gives us the opportunity to acquire this critical data, often in parallel with existing operations, or acquiring it in real-time during the rig operation we are using the data for. We will demonstrate how this tool was designed, and some of the key differences between this and a wireline conveyed tool. These differences presented some specific challenges that needed to be overcome, not only in the mechanical design of the tool, but also in the way it handles and processes data downhole. We will then show, through case histories, some of the data sets acquired and their comparison with wireline for qualification of the tool. The field results will show the full range of measurements which this tool is capable.