bluuebunny/crossref_metadata_2025_split huggingface dataset:
Appropriately Characterizing Uncertainty in Estimated Ultimate Recovery for Unconventional Type Wells
Authors: Miller Patrick , Dauncey Keane , Gouveia James 
Published: October 2020

Abstract
Building type wells is arguably the most important exercise in decision making for unconventional resource plays. The type well and its associated uncertainty are often the largest drivers behind whether a project will be economic, or not. However, appropriately characterizing type well uncertainty is not trivial, and is often overlooked.
Recently, new methods have been developed to help estimate type well uncertainty; these methods include statistical aggregation, which reflects the idea that if more information is available, the type well uncertainty band should be narrower. Unfortunately, aggregation is often misapplied to Estimated Ultimate Recovery (EUR) estimates, ignoring the inherent uncertainty and bias in those estimates, which results in a type well uncertainty band that is too narrow. This paper demonstrates how to account for uncertainty and bias in EUR forecasts with a simple, practical Monte Carlo model.
To develop proper type wells, it is critical to distinguish between measured data and estimated data. The type well should have a narrower band of uncertainty where information is measured and tangible (initial production rates) compared to where it is estimated and intangible (EUR).This paper presents a workflow to easily capture this dynamic between initial production rates and EUR in the context of type wells. The concepts of the workflow are first illustrated with a simple analogy of estimating the mass of a bag of marbles; next, the concepts are applied to build example type wells for a real unconventional play.
A key implication of this work is that collecting new information (i.e. new well production data) does not always narrow the uncertainty band for type well EUR. The EUR uncertainty band depends not only on the number of wells with production data, but also on the P90-P10 ranges of individual well forecasts, bias of the evaluator,amount of production data, and consistency in well characteristics. Rules of thumb are developed to help integrate these factors into the final type well workflow and uncertainty assessment.
Developing Professionals Skills Through an Innovative Methodology of Transfer Knowledge
Authors: Velasquez Sergio , Ardila David , Pastor Chacon Paola Andrea , Galvis William Genghini , Ramirez Leyla , Tarazona Fabio 
Published: October 2020

Abstract
Oil price downturn has directly affected employability in our industry at a global scale since 2014, dropping the workforce to significantly low levels. In Colombia, many young professionals finished the undergrad with the intention of building a competitive industry and leverage the national economy through their knowledge; however, most of them have not even had the chance to get a first job as they are in a market that values the experience they do not have. Having said this, it makes evident the need of differentiation from candidates in selection processes and considering other alternatives for their life projects.
As a social responsibility act, the SPE Colombian Section – in conjunction with volunteers working on technical and human resources areas - created a solid strategy based on real needs concluded from data collected at SPE Colombian Section events to boost up young professionals development path and provide guidance for decision making on their careers. "ENJOG" Encuentro de Jovenes de la Industria de Oil and Gas proved that to join efforts is the best way to break barriers and to solve problems.
The results have shown a significant impact on those involved in the program created and the knowledge worth reproducing is documented in this paper. More than 500 young professionals have been participating in the strategy.
Semi-Analytical Modeling of Multi-Fractured Horizontal Gas Wells with Variable Production Constraints and Fracture Interference
Authors: Garcez Jonathan , Zhang Miao , Ayala Luis F. 
Published: October 2020

Abstract
This paper presents a semi-analytical method based on an integral formulation derived through Green’s Function Method to model multi-fractured horizontal gas well (MFHWs) production performance experiencing fracture interference. The nonlinear effect of retaining pressure-dependent gas properties, namely viscosity-compressibility product, in the pseudopressure-based gas diffusivity equation is rigorously captured in the proposed method, removing previous approximations used in existing conventional production data analysis methods. The proposed method is validated against finely gridded numerical simulations models to demonstrate the capabilities of the proposed approach to forecast multi-fracture horizontal gas well performance - including early and late time periods. Fracture spacing sensivity analysis is performed to showcase the importance of a proper hydraulic fracking design to improve the well productivity.
Feasibility of Combining Gas-Assisted Gravity Drainage GAGD with Water Injection in a Thick Heterogeneous Carbonate Reservoir Using 3-D Experimental Physical Model and Simulation
Authors: Peng Yingfeng , Li Yiqiang , Sarma Hemanta K. , Gao Shenen , Kong Debin 
Published: October 2020

Abstract
Enhancing oil recovery from thick heterogeneous carbonate reservoirs poses great challenges, be it through waterflooding or gasflooding. In this study, a three-layer 3D physical model was established based on artificial core technology and scaling criteria, taking into account the mineral composition, petrophysical properties, pore structure, wettability, heterogeneity, dynamic, bottom aquifer, interlayers, and well pattern. Experiments were carried out under circumstance of high temperature and high pressure. A numerical simulation model incorporated with local geological characteristics was built for subject well-area unit. The development process and ultimate oil recovery of conventional water injection, gas-assisted gravity drainage (GAGD), edge-bottom water injection (EBWI), and a method of combination of GAGD and EBWI proposed in this paper, named CGE were studied. For this kind of reservoirs, the experiments showed that, oil recovery of GAGD and EBWI were 40.01% and 37.11%, respectively, higher than conventional waterflooding process, while CGE had the most potential with oil recovery 43.85%. The numerical simulation showed that, oil recovery of CGE was 49.87% and the water cut was extremely low in the first 11 years. GAGD significantly increased Bond Number and had strong water control ability, but it relied on the pressure accumulation, thus there was a non-effective period. EBWI had no obvious non-effective periods, and thus enhancing oil recovery in the early stage through forced gravity displacement. CGE is a feasible and efficient combination development method, although there is still a problem of water control in the later stage. In addition to the research of EOR methods, this paper also helps broaden the means of researching carbonate reservoirs and design more schemes, based on the successful implement of the experiments.
Institutional Cooperation for Capacity Building of a Petroleum Engineering Department: A Case Study
Authors: Khan Abid , Tjåland Egil , Kleppe Jon , Lodi Sarosh 
Published: October 2020

Abstract
Pakistan requires intensive exploration activities and rapid development of its indigenous oil and gas resources. A well trained professional human resource, equipped with modern tools and skills, is essentially required. To achieve this, the Norwegian Centre of Excellence for Petroleum Studies (NCEPS) at NED University was established through collaborative efforts of NED University of Engineering & Technology (NEDUET) Pakistan and Norwegian University of Science & Technology (NTNU) Norway, in close cooperation with Petroleum Industry, under the umbrella of Pak-Norway, Institutional Cooperation Program.
The establishment of NCEPS included a six-pronged approach for capacity building of Petroleum Engineering Department at NEDUET. These included: i) post graduate studies and training programs for faculty members and laboratory staff, ii) strengthening of laboratory and office resources, iii) development of Master program, iv) transfer of technology, v) initiation of collaborative research, and vi) development of linkages between the two universities and the petroleum industry.
The main objective was achieved through capacity building of academic staff and strengthening of laboratory facilities at NED Universities. Among faculty members, four received master's degree, three were trained on latest teaching techniques, two received capacity building in research and five laboratory engineers were trained on laboratory equipment handling and operation. It also included a special training on drilling simulator at Abu Dhabi. Strengthening of laboratory resources have been undertaken through procurement of state-of-the-art research equipment. Master's program was also developed in collaboration with NTNU and industry. Transfer of latest teaching techniques has been acquired. A video conferencing facility was also developed to provide effective communication and learning opportunities. Sustainable linkages between academia and industry were enhanced.
The petroleum engineering department shows significant improvement in providing quality education, professional training and industry-oriented research. The experience was shared with other institutions in the country. Sustainable linkages have been developed between the two universities and the industry. This paper provides details of these tri-partite collaborative efforts.
Cellulose Nanocrystal Switchable Gel for Improving CO2 Sweep Efficiency in Enhanced Oil Recovery and Gas Storage
Authors: Telmadarreie Ali , Johnsen Christopher , Bryant Steven 
Published: October 2020

Abstract
CO2 injection is regarded as an important method for enhanced oil recovery (EOR) and greenhouse gas control by storing CO2 underground. However, the reservoir heterogeneity and low viscosity of CO2 will result in poor sweep and therefore inadequate oil recovery and inefficient gas storage. The entanglement of biopolymers is a well-known phenomenon that, when controlled, can result in a smart fluid with strong gelation properties. We have shown that when a suitable salt is incorporated into the cellulose nanocrystal (CNC), the fluids undergo gelation upon contact with bulk phase CO2 but remain a flowing liquid otherwise. In this study, we applied this composition-selective trigger to improve the sweep efficiency in CO2 EOR and sequestration.
Benchtop tests were performed to observe the gelation time and strength of gel to optimize the chemical concentrations accordingly. Parameters such as CNC and salt concentrations were optimized to tune the gelation time and gel strength. The optimized CNC fluid was tested for its ability to turn to gel within the porous medium as CO2 encounters the fluid. Flow tests were performed in a representative model porous media to analyze the in-situ gelation inferred from pressure profile and fluid production. CO2 and N2 gas were used as the gas phases. A heterogeneous dual-sandpack was used to demonstrate sweep efficiency improvement during CO2 injection.
Tuning the chemical concentration enabled us to optimize the gel strength and more importantly gelation time across a wide range, from 5 minutes to more than 48 hours. The gel can be easily broken in contact with nitrogen gas. After CNC+salt fluid was placed in porous media initially containing water and CO2, subsequent injection of CO2 required a very large pressure gradient to initiate flow demonstrating the in-situ generations of gel. Once the flow was initiated, subsequent sequential injections of CO2 and N2 exhibited smaller resistance to N2 than to CO2, consistent with the reversible gel/solution transition in the presence/absence of CO2 observed in batch experiments. Flow tests in heterogeneous dual-sandpack (with permeability contrast of 5) revealed that in-situ gelation diverts injected CO2 almost entirely to the lower permeability layer, which had been almost completely bypassed during injection prior to the CNC+salt injection.
The composition-specific trigger, the ability to control the fluid's properties, and the renewable source of nanomaterials will open up an enormous opportunity for CO2 injection processes in heterogeneous reservoirs, in challenging locations (i.e. offshore) and in related applications such as CO2 sequestration.
Cost Comparison Between Carbon Neutral Fuel and Alternative Low Carbon Energy Options
Authors: Ehlig-Economides Christine , de Guzman Neil 
Published: October 2020

Abstract
In efforts to reduce carbon dioxide emissions from fossil fuel combustion, public funding for wind and solar alternative energy resources has enabled their evolution toward cost competitiveness with coal and natural gas options for electric power generation. To address combustion emissions from the transportation sector, the European Commission has committed to electrifying transportation, but this solution will not address transportation by air or by sea. Nor does it address continued production of petrochemical products that only require a small fraction of produced hydrocarbons. This study investigates the cost competitiveness of an alternative strategy to market crude oil priced to cover the cost of removing an amount of carbon dioxide equal to that produced through combustion of transportation fuels to be refined from it. This strategy enables continued use of fossil fuel for all transportation modes.
The cost comparison considers life cycle carbon dioxide emissions and does not address other externalities related to materials or batteries employed in renewable energy options. Rather, we report known costs for carbon capture, use, and storage (CCUS) with consideration of both nature and technology based carbon capture with focus mainly on geologic storage and utilization.
Because road and rail transportation can be electrified, of particular interest is the levelized cost comparison between carbon neutral fuel and electrified transportation, the latter including infrastructure implementation costs.
The resulting cost comparison informs investment decisions and justifies marketing fossil fuels on a carbon neutral basis.
Geomechanics of Compartmentalized Reservoirs with Finite Element Analysis: Field Case Study from the Eastern Mediterranean
Authors: Markou Nikolaos , Papanastasiou Panos 
Published: October 2020

Abstract
This paper presents an optimum way to produce down to depletion a compartmentalized reservoir in offshore deep environment by considering geomechanical stress-deformation mechanisms and associated problems. The case study is for a faulted reservoir zone of the Aphrodite field, located in the Eastern Mediterranean. The study is based on finite element modelling using 2D plane strain analysis that incorporates pore pressure and elastoplastic deformation of reservoir and overburden rock formations using the Drucker-Prager plasticity model. The mechanical properties of the reservoir sandstones were derived from calibration of data obtained from triaxial tests and for the overburden shale layers from acoustic velocities and correlation functions. The compartmentalized geometry was constructed based on seismic data and logging data obtained at the exploration and appraisal phases. The estimated insitu stress field was transformed and applied on the boundaries of the model blocky geometry.
Four different initial and equilibrium depletion scenarios were examined and the obtained results in terms of deformation and effective stresses are compared. The first scenario reflects the initial stress state, the next two intermediate scenarios present non-uniform depletion cases for each fault block, and the fourth scenario presents the case of a uniform depletion. It was found that the uniform depletion of the reservoir compartments creates the least stress contrast in the field and consequently, ensures better control of stress-related impacts during the production. The analysis highlights the local regions of a fault blocks system that potentially suffer by high shear strains that can cause fault reactivation or induced fractured zones but the over-all risk remains low. Furthermore, the analysis establishes relationships between the mean effective stress, volumetric strain, and permeability changes in order to predict the regions with improved transmissibility characteristics or the less permeable compacted rock regions of the reservoir. Overall, the analysis can provide an appreciation of the stress/strain-driven characteristics of the reservoir showing the area of rock compaction tendencies of the faulted blocks and the further deformation in depletion conditions. The presented work demonstrates clearly that a properly calibrated reservoir geomechanical model can be used as a screening tool for examining depletion scenarios of compartmentalized reservoirs, highlighting areas of potential problems such as fault activation, wellbore shearing, reservoir compaction, permeability changes and fault sealing.
Data Determine the Optimal Drawdown for Woodford and Mayes in the Anadarko Basin
Authors: Alzahabi Ahmed , Trindade A. Alexandre , Kamel Ahmed , Harouaka Abdallah , Baustian Wade , Campbell Catherine 
Published: October 2020

Abstract
One of the continuing puzzle pieces for all unconventional plays is drawdown (DD) technique for optimal Return on Investment (ROI). A solid approach to determine this valuable piece of information has yet to be found, as many operators are reluctant to reveal the production, pressure, and completion data required. Among multiple parameters, various completion and spacing parameters add to the complexity of the problem. This paper aims to determine which drawdown strategy leads to the highest return in the Anadarko Basin,, specifically evaluating the Woodford and Mayes formation. Several drawdown techniques were used within the Anadarko Basin in conjunction with different completion techniques. Private production and completion data were analyzed and combined with well log analysis in conjunction with data analytics tools. This case study explores a new strategy to drawdown producing wells within the Anadarko basin to achieve ultimate ROI. We perform data analytics utilizing analytics (scatterplot smoothing) to develop a relationship between two dependent variables Estimated Ultimate Recovery (EUR) and Initial Production (IP) for 180 days of Oil vs. drawdown. We present a model that evaluates horizontal well production based on drawdown parameters. Key data were estimated using reservoir and production parameters. The data led to determination of the most optimal drawdown technique for different reservoirs within the Anadarko Basin. This result may help professionals fully understand the Anadarko Basin. By use of these optimal parameters, we hope to completely understand the best way to drawdown wells when they are drilled simultaneously. Our findings and workflow within the Woodford and Mayes formations may be applied to various plays and formations across the unconventional play spectrum. Optimal drawdown techniques in unconventional reservoirs could add billions of dollars in revenue to a company's portfolio and increase rate of return dramatically, as well as offer a new understanding of the reservoirs in which we are dealing with.
Successful Overflushing of Hydraulic Fractures Using Crosslinked Fluids in Conventional Permeability Reservoirs: Theoretical Basis for a Paradigm Shift with Field Results
Authors: Vitthal Sanjay , Chapylgin Dmitry , Liu Xin , Khamadaliev Damir , Fair Phillip 
Published: October 2020

Abstract
During hydraulic fracturing of low to moderate (0.1 – 50 md) permeability reservoirs using crosslinked gel fluids, the final proppant stage displacement is designed to leave some volume of proppant slurry above the perforated interval. This practice of underflushing is based on a paradigm that considers the overdisplacement of proppant past perforations to be a major risk to well productivity. The theory behind this paradigm is investigated and finds that it relies on several physically unrealistic assumptions. Numerical simulations were performed to understand the impact of a fracture overflush on well productivity. A new methodology was developed for overflushing fractures that enables significant cost/time savings without impacting well productivity. A multi-well field trial in a 2-20 md reservoir was conducted andcompared well performance from overflushed crosslinked gel fractures to underflushed fractures. Some of the trial results have been reported by the authors (Chaplygin et. al. (2019)) and are further updated/analyzed in this work. The analysis confirmed that the managed overflush fractures have equivalent performance to underflushed fractures. The analysis also confirmed multiple benefits from the managed overflush wells including reductions in completion costs/time and an improved HSSE risk profile. The results challenge the validity of this decades old paradigm.
An Operator and Rig Contractor Deliver Drilling Process Automation in the Bakken
Authors: Isbell Matthew , Munoz Ernest , Ramseyer Lacey , Farrow Blakley 
Published: October 2020

Abstract
An operator and rig contractor implemented new drilling operation automation (DOA) on two rigs in North Dakota’s Bakken field. A set of DOA projects were selected to promote alignment and deliver valuable tools to improve operational performance based on a collaborative technology agreement to develop innovative DOA process solutions to reduce operational variation. The first sprint of project work focused on delivering a system that automatically carries out recurring drilling activities previously completed manually by a driller interfacing with drilling rig controls.
Collaboration between the operator and rig contractor has been vital in developing technical workflows for automation that deliver value to all stakeholders. The operator and rig contractor developed, field tested, and proved the value of the implemented devices and systems. The project development process is described along with the methods used to overcome the challenges encountered during the first project sprint. Developing and deploying repetitive process automation has enabled greater control and driven operational consistency for repetitive drilling practices. The process will be shared to manage, design, and implement automated sequences to the field. The first project sprint delivered a valuable drilling system which executes automated drilling operations. This tool will act as a platform for the next stages of project work to improve management of a drilling automation plan and operations at the rig site. The results described in this paper were outlined as future steps in SPE 195818.
The operator and rig contractor overcame some of the traditional cultural and technical barriers to efficiently develop DOA through technology collaboration. The project team used the operators’ standard well delivery processes to deliver a valuable tool to aid the driller’s workflow while standardizing repetitive and recurring steps in drilling operation activities. Engaging and collaborating with field personnel drove improvements to the automated processes and enhanced the value-adding tools to impact operations at a field level.