bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maximising Asset Value through Implementation of Dynamic Well Operating Envelop
Authors: Islamov Rafael , Motaei Eghbal , Madon Bahrom , Abu Bakar Khairul Azhar , Hamdan Victor , W M Zani Luqman 
Published: March 2021

Abstract
Dynamic Well Operating Envelop (WOE) allows to ensure that well is maintained and operated within design limits and operated in the safe, stable and profitable way. WOE covers the Well Integrity, Reservoir constraints and Facility limitations and visualizes them on well performance chart (Hamzat et al., 2013).
Design and operating limits (such as upper and lower completion/facilities design pressures, sand failure, erosion limitations, reservoir management related limitations etc) are identified and translated into two-dimensional WOE (pressure vs. flowrate) to ensure maximum range of operating conditions that represents safe and reliable operation are covered. VLP/IPR performance curves were incorporated based on latest Validated Well Model. Optimum well operating window represents the maximum range of operating conditions within the Reservoir constraints assessed. By introducing actual Well Performance data the optimisation opportunities such as production/injection enhancement identified.
During generating the Well Operating Envelops tremendous work being done to rectify challenges such as: most static data (i.e. design and reservoir limitations) are not digitized, unreliable real-time/dynamic data flow (i.e. FTHP, Oil/Gas rates etc), disintegrated and unreliable well Models and no solid workflows for Flow assurance. As a pre-requisite the workflows being developed to make data tidy i.e.ready and right, and Well Model inputs being integrated to build updated Well Models. Successful WOE prototype is generated for natural and artificially lifted Oil and Gas wells. Optimisation opportunities being identified (i.e. flowline pressure reduction, reservoir stimulation and bean-up)
Proactive maintenance is made possible through dynamic WOE as a real time exceptional based surveillance (EBS) tool which is allowing Asset engineers to conduct the well performance monitoring, and maintain it within safe, stable and profitable window. Additionally, it allows to track all Production Enhancement jobs and seamless forecasting for new opportunities.
A Business Case for Drilling Automation: Well Cost Compression by Suppressing Downhole Tool Failure in Low Oil Market
Authors: Kusumawardhani Danaparamita 
Published: March 2021

Abstract
In a difficult situation where the oil market is down, reducing drilling cost is always an interesting outlook to be pursued. To do so, one should consider looking at the highest component on the drilling cost. Down-hole equipment failure and stuck pipe is avoidable during the engineering planning. It is well-known that billions of dollars have been lost and numerous Bottom-Hole Assembly (BHA) are left in the well due to such problems, related to stick-slip phenomenon. Thus, despite the low oil price, it is a new normal that some asset owners opt to invest on high-end tools to prevent stick-slip, meanwhile others are still reluctant because of its high initial costs and chose to solely focus on the technical skills to drill faster. The objective of this paper is to determine whether, and which, utilization of these automations will be an effective method to lower overall cost, between using Anti-Stick Slip Technology (AST), Surface soft-torque, Self-Adjusting PDC Bit or all three combined together.
The analysis of this project is conducted by providing conjecture in comparative method to visualize the configuration. In each case, estimated Rate of Penetration (ROP) is observed based on the recent literature of its application in similar lithology which is carbonate and interbedded shale. As the ROP increases, the overall drilling cost along with percentage of potential net saving for each case is evaluated in this study and select the most effective strategy.
The outturn suggests that despite the high initial investment, combining all technologies are economically advantaged. With the DOCC by the self-adjusting PDC bit and torque alleviation by AST to handle the rock interface in addition to BHA torque wave mitigation from surface by surface soft torque, the ROP is quantified as summation of all cases’ ROP gained as the tool complements each other. The estimated ROP of the case significantly gives high decrement of the overall cost and boosted the potential net saving. Moreover, prevention from NPT due to downhole failure and stuck pipe problem is also a contributing factor to increasing cost efficiency. Therefore, combining all the tool together is proven to be the most favorable option aside from, respectively from preferable to the less, utilizing Surface Soft Torque, Self-Adjusting PDC Bit, and AST. Although it requires high initial investment, it is worthwhile to explore the usage of automation technologies for the overall cost reduction contributes to make the case financially attractive.
Application of Sh S-Wave Data in Lithologic Trap Identification
Authors: Guo Jiru , Deng Zhiwen , Zhang Junyong , Tan Wei , Chen Guowen , Shi Qiao , Wang Yaling , Zhao Qian 
Published: March 2021

Abstract
The biogas lithologic reservoirs in Sanhu Area of the Qaidam Basin has a broad exploration prospect, however, the demands of structural implementation and reservoir prediction can hardly be met with the existing P-wave seismic data due to the thin thickness of single sandstone layers, the rapid lateral changes and the low prediction accuracy of lithologic reservoirs. The SH-wave data has a higher resolution ability in lithology prediction. I can better reflect the lateral change features of formations. Because few SH-wave logging data are available and they are in accurate in the current study area, the SH-wave velocity is estimated through petrophysical modeling and the calibration and horizon interpretation of the SH-wave data are realized combined with the P- and SH-wave matching technology. Through the inversion of S-wave data,the lithological distribution of formations are predicted in combination with the comrehensive analysis of P-wave data, which provides a favorable basis for the survey of lithologic gas reservoir in the research area and achieves a good good result. In this way,a set of reservoir prediction methods and processes suitable for the shallow biogas lithological exploration in the Sanhu Area have formed initially.
Integration of 3D Geological Modeling and Fault Seal Analysis for Pore Pressure Characterization of a High Pressure and High Temperature Exploration Well in Nam Con Son Basin, a Case Study Offshore Vietnam
Authors: Nguyen Son.T. T , Nguyen Tan.N. N , Tran Hung.N.T. N.T , Ngo Quan.A. A 
Published: March 2021

Abstract
The pore pressure profile of an exploration well in high pressure and high temperature (HPHT) A-Field of Nam Con Son Basin was initially predicted along the wellpath in tandem with the analogy to an offset well to design a drilling program of penetrating the unreachable sedimentary formation. The scheme had driven mud weight to encounter the pressure ramp but resulted in underbalance and influx into the wellbore that incurred downtime for well control. Subsequently, formation pressure measurement conceded the substantial disparity over the offset well so the post-drill study was conducted towards with 3D geological modeling and fault seal analysis to gain insight into overpressure generation mechanisms of the field.
Seismic interval velocity, density, resistivity data are applied for generating the validated pore pressure profile of exploration well on both Eaton and Bowers methods with calibration on formation pressure measurement for Middle and Lower Miocene Sequences. Besides, the cutting edge 3D modeling is approached to construct a robust structural and fault framework as well as to condition and upscale ultimate shale volume, pressure gradient, and overburden stress for facies and pressure distribution. The sealing capacity of a fault is quantified in terms of the pressure acting on the fault surface that is required to be exceeded for the fault to become unstable and slip including simulations of formation juxtaposition mapping, fault clay content prediction, fault flow indicators, and transmissibility.
Upon completion of the 3D model, the fault surfaces which are mapped by shale volume could provide a detailed geometry and lithology juxtaposition analysis for the fault planes. The results of the high Shale Gouge Ratio (SGR), very low fault permeability, and relatively high fault rock thickness imply that the studied faults act as a baffle to fluid flow. However, from juxtaposition observation, the displacement broadens with depth in some parts of faults and the lateral stress increases through the sync-rift stage of Middle Miocene could be a cause of overpressure in this studied area.
The 3D pore pressure and stress regime integrated with fault seal analysis in the model are generally obtained to provide both vertical and spatial overpressure characterization and advantages for well drilling plan and reservoir production. From the drilling aspect, a fault stability study can optimize the maximum allowable mud weight to not exceed while drilling so that fault reactivation does not take place. From a depletion perspective, understanding of stress variations due to lowering reservoir pressure with time can be incorporated with fault seal analysis.
Improving Cement-to-Pipe Bonding Evaluation on Coated Casing
Authors: Lumankun Barry Albert , Adiningtyas Diyah Ayu , Azwar Cinto , Osman Ahmed , Hartanto Rudi , Tanjung Erwindo , Abdila Sayid Faisal 
Published: March 2021

ABSTRACT
In the Oil and Gas industries, drilling a well in both exploration and development operations is becoming more challenging due to the reservoir location and complex reservoir system. A sophisticated high-cost well structure with complex trajectory, subsea system, or even operating in deep water is sometimes unavoidable. One of the crucial factors for a successful well construction operation is to achieve excellent well integrity by having good zonal isolation throughout the target reservoir section. This requires flawless primary cementation from cement job planning, design, and up to execution. The cement bond quality will need to be evaluated by performing the post job cement execution evaluation and wireline logging cement bond log survey.
Supported with more stringent regulations, well integrity is becoming a fundamental aspect in drilling and production operations. This brings new challenges to cementing operations and subsequent cement evaluation. Flawless primary cementation is of great importance, from the job planning, design, to the execution. Post-job cement evaluations are needed by performing Pressure Match Post-Job Analysis and Wireline Logging Cement Bond Log Survey.
Key parameters in designing optimum zonal isolation cement slurry is good understanding of the wellbore technical challenges and mitigating all geological and formation-related risks, such as narrow pressure margin, gas migration risk, etc. Light cement, complicated cement composition recipes, small cement - mud weight ratio are more common these days, supported with the developing technology in cementing. These, on the other side, would impact the cement bond evaluation.
Good cement bond is crucial to ensure good zonal isolation across the reservoir intervals. Casing external coating, applied to protect casing strings from rusts, is another aspect affecting the cement bond, especially cement-to-casing bond. A more advanced cement bond evaluation tool will be required to cope with variety of cementing conditions, to enable producing undoubted log results. Thus, helping Operator in making decisions of subsequent well operations.
This paper shows and presents different cement bond log interpretation results from four wells executed with a different method of implementations, performed in a development drilling campaign in Natuna Sea, offshore Indonesia in year 2019. The paper will focus on the 9-5/8" casing cementation, on which the cement bond evaluation became one of the main attentions.
Evaluation and Optimization of Adsorption Reduction Strategies on Chemical EOR Economics
Authors: Wartenberg Nicolas , Kerdraon Margaux , Salaun Mathieu , Brunet-Errard Lena , Fejean Christophe , Rousseau David 
Published: March 2021

Abstract
This paper is dedicated to the selection of the most effective way of mitigating surfactant adsorption in chemical EOR flooding. Mitigation strategies based on either water treatment or adsorption inhibitors were benchmarked for a sea water injection brine, on both performances and economics aspects. Performances in surfactant adsorption reduction were evaluated by applying salinity and/or hardness gradient strategies through dedicated water softening techniques, such as reverse osmosis or nanofiltration. Adsorption inhibitor addition, which does not require any water treatment, was also assessed and optimized for comparison. For each scenario, a suitable surfactant formulation was designed and evaluated through phase diagrams, static adsorption and diphasic coreflood experiments. Then the real benefit of surfactant adsorption reduction on the overall EOR process economics (including the costs of chemicals and water treatment) was assessed depending on the selected strategy. Sea water was considered as the injection brine for this study as it is widely used in chemical EOR process and often suffers high surfactant adsorption level. It was found that residual oil saturation after chemical flooding (SORc) dropped from 29% to 7% by applying a hardness gradient through nanofiltration process while 4% was reached with reverse osmosis. Regarding costs and footprint however, nanofiltration was found to be more advantageous. Adsorption inhibitors addition met similar performances to nanofiltration-based process (SORc=7%) and could be a valuable option depending on injected volume (pilot or small deployment) or field location (off-shore) as they do not require water treatment plant investment. Overall, this study provides useful practical insights on both performances and economics for selecting the most adapted strategy depending on the considered field case.
Formation Kinetics and Self-Preservation of CO2 Hydrates in the Presence of Carboxylated Multiwall Carbon Nanotubes
Authors: Mohamad Sabil Khalik , Nashed Omar , Lal Bhajan , Foo Khor Siak 
Published: March 2021

Abstract
Nanofluids are known of having the capability to increase heat and mass transfer and their suitability to be used as kinetic gas hydrate promoters have been recently investigated. They have favorable properties such as high thermal conductivity, large surface area, recyclable, ecofriendly, and relatively cheap that are favorable for kinetic gas hydrate promoters. However, the nanomaterials face challenges related to their stability in the base fluid. Therefore, it is crucial to investigate the impact of surfactant free nanofluid on hydrate formation and dissociation kinetics. In this work, COOH-MWCNT suspended in water is used to study the effect of surfactant free nanofluid on CO2 hydrates formation kinetic and stability. Kinetic study on CO2 hydrates formation as well as self-preservation are conducted in a stirred tank reactor. The kinetic experiments are carried out at 2.7 MPa and 274.15 K. The induction time, initial gas consumption rate, half-completion time t50, semi completion time t95 are measured to evaluate the effect of COOH-MWCNT. Furthermore, the dissociation rate was calculated to assess the impact of COOH-MWCNT on self-preservation at 271.15 K and atmospheric pressure. The results are compared with that of sodium dodecyl sulphate (SDS). The study of CO2 hydrates formation kinetic shows that the induction time is not affected by COOH-MWCNT. The impact of nanofluid is more pronounced during the hydrate growth. The initial formation rate is the highest at 0.01 wt% of COOH-MWCNT whereas 0.01 and 0.03 wt% shows the same and shortest t50. However, t95 found to be decreased with increasing the concentration. The effect of COOH-MWCNT is attributed to the strong functional group. Self-preservation results shows CO2 hydrates are less stable in the presence of COOH-MWCNT. The result of this work may provide significant finding that can be used to developed kinetic gas hydrate promoter based on nanofluid that work better than SDS to eliminate gas hydrate formation in oil and gas pipeline.
Mass Transport and Exchange Inside Tight Matrix-Fracture Systems During CO2 Huff-n-Puff and Flooding Processes
Authors: Wei Bing , Zhong Mengying , Tang Haoran , Wang Lele , Gao Ke , Lu Jun 
Published: March 2021

Abstract
The potential of CO2 injection in stimulating tight oil recovery after primary production has been extensively demonstrated previously. However, the processes of mass transport and exchange inside dual-permeability matrix-facture system driven by CO2 remain unclear. To improve our understanding and supplement the existing knowledge, three types of matrix-fracture models were designed and employed to mimic CO2 injection processes (huff-n-puff and flooding modes), named fully open fracture (FOF), partially open fracture (POF), and crossed open fracture (COF) models, respectively. CO2 huff-n-puff and flooding experiments were conducted on these three models to observe the dynamics of pressure and oil recovery factor. Core-scale models were built up by history-matching the oil recovery dynamics through modifying the relative permeability curves based on Corey correlations. The mass transport and exchange processes with the proceeding of CO2 injection were delineated. The results showed that either CO2 huff-n-puff or CO2 flooding was capable of extracting the oil from tight matrix substantially but the increase in oil recovery factor became insignificant with the increase in cycle number or injection time. The oil resided in the proximity of injector, fracture and producer were primarily recovered during CO2 flooding. In the FOF and COF models, the matrix oil near the injector and producer was mainly mobilized. As for CO2 huff-n-puff, the oil saturation of the three models was reduced uniformly throughout the cores with cycles. The high sweep efficiency of CO2 largely mobilized the oil near the injector. It can be generally concluded that injecting CO2 by huff-n-puff protocol might be more beneficial than flooding mode for unconventionals. The results of this paper can provide insights into the oil recovery dynamics and mass transport and exchange induced by CO2 injection in tight reservoirs.
Alternative Method of Assessing Optimum Number of Water Injection and Infill Wells in a Field Development Plan
Authors: Ramli M. Fitri , M. Long M. Shahrul , Pote Amol Nivrutti , Ishak Khairul Azri 
Published: March 2021

Abstract
This paper discusses the workflow and method of selecting optimum number of infill and injection wells based on incremental recovery. Normally, for infill wells study, a ‘creaming curve’ method is used to evaluate the optimum number of wells against incremental recovery from the field. However, in the case of determining number of infill wells together with water injection wells, a more comprehensive approach is needed. One needs to evaluate the pressure depletion rate from existing and infill wells together with the dynamic of the producer-injector pairings as well as the sweeping factor.
The paper is based on infill and water injection development plan for a brown field in Sabah basin which located in Malaysia. To maintain operatability of the field in the future, several new infill and water injection wells options are evaluated for optimum field life oil production. Unlike infill or producer-only assessment, the same ‘creaming curve’ approach for combination of infill and water injection wells is less effective as large number of simulation runs are needed to sample the combination of these wells that generate optimum oil recovery. This has proven to be challenging especially when the models are large which is normally the case for brown fields and it requires extensive computational hours.
In the first part, a modified approach bringing some pre-analytic assessment of producer-injector pairing is being used. The pairings are first ranked based on streamlines visualization, drainage tables and their respective contributions towards oil recovery. The ‘creaming curve’ is then built based on the highest contribution as well as the sequencing of the pairings. The second method mentioned in this paper is the numerical approach through multi-objective optimization using assisted history matching and uncertainty tool. With the help of optimizer, the number of simulation runs can be drastically reduced when only best combination of infills and injectors for each total number of wells are considered.
Both alternative methods will be compared with the full computational runs, sampling every single combination of wells. Finally, the optimum number of wells with the combination of infill and water injection wells are analysed based on cumulative oil recovery against the Net Present Value (NPV). This case study therefore demonstrates how alternative methods can be used to resolve the optimum number of infill and water injection wells to avoid lengthy and very large numbers of simulation runs.