bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Proper Well Spacings – A Supplementary Method to Maximize The Gulf of Thailand Development Project Value
Authors: Hotapavanon Pitchaya , Suyacom Kasinee , Chuachomsuk Korakoch , Thapchim Jiraphas , Nasomsong Rutchanok , Chaipornkaew Metsai 
Published: February 2023

ABSTRACT
For The Gulf of Thailand (GoT) projects, the bulk of investment goes in drilling development wells and the financial return is depending on how much reserve is effectively tapped by those wells. To improve project economics, both optimizing the well placements to access hydrocarbon and minimizing the number of wells are required. This study shows how proper well spacing used in development well planning is defined using the understanding of reservoir connectivity ratio at a given well spacing.
Firstly, reservoir correlation panels of wells drilled within the same trapping fault were created and the reservoir connectivity ratio at a given well spacing were collected. Hence the cross-plot between various well spacing and reservoir connectivity ratio was constructed to establish relationship. New reserves were derived by new pay from the spacing-connectivity relationship and estimated ultimate recovery per metre (EUR/m). With the estimated reserves varied by well spacing, the proper well spacing can be defined by identifying the narrowest well spacing that yield new incremental reserves above economic cut-off.
More than 100 cross-plots from Arthit project were conducted by using the existing wells information, the results suggest that a relationship between well spacing and reservoir connectivity ratio is varying depended on trap style, fault strike, channel width & oblique angle and hydrocarbon column height. A new/share pay ratio template is now available to illustrate an expected new/share pay ratio at a given well spacing (ranged from 100 m. to 1,500 m.) in each HC pay unit and subsurface geological trend. From the result, new pay ratio is in the range of 45%-60% at the current well spacing (400 m.) of Arthit Project. Based on the economic justification of Arthit project, there is the opportunity to narrow down well spacing for being economically viable in the future.
The optimum well spacing together with an economic viability analysis in each project could be done efficiently. Shortly, the proper given well spacing will be proactively planned for both infill and new wellhead platform. The 2021 infill projects help to validate the current model, improve the prediction function and certainly narrow down those uncertainties for future development projects.
Development planning would benefit greatly from proper well spacing so that the optimum number of wells is known upfront so project planning could be properly managed. If tighter well spacing could be applied, more wells could be filled into existing platforms. Then the big investment on new platforms could be deferred. Moreover, this method can be also broadened to other projects where GoT development model can be applied to achieve optimum commerciality.
Holistic Approach to Determine the Fracture Propagation Pressure (FPP): Consistent Interpretation of Step Rate Tests Using Multiple Analysis Methods
Authors: Cobanoglu Mustafa 
Published: February 2023

AbstractA Step Rate Test (SRT)‘s is frequently performed method used to accurately measure fracture propagation pressure (FPP) of a given geologic formation. The injection rates in the test are increased in steps from low rates below fracturing pressure to high rates above fracturing pressure, allowing each rate to stabilize, and noting the stabilized injection pressure for each rate. Then, as classic approach, pressure at the end of each injection step versus injection rate are plotted. The fracture propagation pressure occurs at the intersection of the two straight lines. Then main assumption of the classic approach is that there are "2 distinct different regions with constant properties (i.e. KH & skin)" during multi rate injection test and those regions are the one without "induced fracture" region and the one with "induced fracture" region (i.e. post frac region). However, post-frac region properties is not going be constant since fracture dimensions changes injection pressure.Therefore, the purpose of this paper is; To explore the pitfalls of the classic approach (pressure versus rate) by including derivation of the mathematic model for classic approach;To develop/provide other alternative SRT interpretation methods: "Pressure Transient Analysis (PTA) – detailed skin analysis" and "PTA– fall-off analysis"To define a holistic approach using Multiple SRT’s Interpretation methods in order to determine the FPPTo demonstrate the applicability of proposed approach for several SRT casesThe proposed holistic approach was successfully applied to several SRT tests conducted in Brunei, commingled waterflood injector wells. Results showed that; Derived mathematical model demonstrated that "classic approach" is underestimating the FPP: Depending on the reservoir fracturing characteristics, expected 2 regions, which is the basis of classic approach, may not be fully developed. This was also demonstrated by actual SRT data.Classic approach might result in misleading FPP results: 2 out of 4 case has no definitive conclusive results up and there is up to 9 % error in FPP estimation (classic versus PTA approach)Classic approach even sometimes might not provide conclusive FPP results: 1 out of 4 case has no conclusive resultPTA approach (i.e. detailed skin analysis and/or prep & post-frac fall-off analysis) was successfully applied to estimate FPP pressure and it seems to be most reliable method since it has provided conclusive results for all cases.PTA analysis could be extended to determine the induced frac properties (fracture, the fracture length, width & frac properties)Recommendations on how to perform a holistic approach for SRT analysis & how to verify the results with standard PTA approach is provided. In addition, since there is no analytical model for induced fracture (i.e. pressure dependent frac), adopted PTA approach using hydraulic frac modelling to make an estimate for frac length size is also presented
Establishment of a Workflow to Assess Pore Collapse Mechanics During a Series of Loading and Unloading Using Micro-CT Scan and Rock Mechanics Testing
Authors: Hamid Osman , Aljamaan Hamza , Altwaijri Mohammad 
Published: February 2023

AbstractCharacterization of the reservoir rock elastic and plastic behavior is essential to set a series of guidelines for reservoir management, especially during gas storage cyclicity. The reservoir rock is subjected to loading during injection and unloading during depletion. These procedures lead to increases and decreases in the magnitude of the effective stresses in the poroelastic media. The guidelines for the reservoir development should be set to operate the field within the elastic limit of the formation to ensure the undamaged permeability of continuous fluid flow in and out of the reservoir.Based on these factors, there is a need to accurately measure the dynamic permeability and porosity by characterizing the pore space and pore throat collapse for the current and future injection and depletion operations. This invention will achieve this measurement through a series of alternating measures between a three-dimensional (3D) X-ray computed tomography (CT) imaging and triaxial testing. These accurate and actual measurements mainly come from core plugs testing.The process starts (T1) by scanning the core plugs with high-resolution imaging technology to map pore space and pore throat. The samples will be subjected to the first step of loading and unloading during Thick Wall Cylinder (TWC) test using different axial and confining pressure. The samples will be imaged and then mapped in the pore space and pore throat at a time (T2), and these processes will continue for ten cycles of loading and unloading. The results will be interpreted and extrapolated to match the number of injection and depletion scenarios. The fluid flow will be numerically simulated at the pore scale using direct flow modeling within the pore space with the Navier-Stokes-Brinkman equation to evaluate changes in permeability and porosity.Using these novel integrated processes presented by this invention, injection and depletion guidelines will be set for future operations; this methodology also can be used for oil recovery to ensure safe operations within an elastic limit to avoid permeability damage that will lead to safe, effective, and economical operational scenarios.
Study on Rotary Percussion Tool Parameters Optimization and Trial Test Evaluation
Authors: Yulin Tu , Li Bodong , Zhan Guodong , Rached Rached M. , Gramajo Eduardo 
Published: February 2023

AbstractDrilling in hard and abrasive formation represents a major challenge due to the low rate of penetration (ROP). Rotary percussive drilling tools take advantage of both the shear action of drill bit cutters and axial percussion energy to increase the drilling efficiency. Such tools have shown a significant benefit in drilling efficiency enhancement, especially in air drilling with an air hammer. This study focuses on a fluid-type rotary percussive drilling tool development and application to address the significant drilling challenge in drilling hard and highly abrasive sandstone formations. A rock mechanical study is carried out to get the compressive strength and the internal friction of the hard and abrasive formation. Then, a 6-3/4 inch rotary percussive tool is designed and optimized based on a relationship between rock mechanics and the output energy and frequency of the tool. Next, the tool was thoroughly tested in the workshop, and the key parameters were acquired and compared with the design.The tool was trial tested in a hard and abrasive formation dominated by fine sandstone and siltstone in the upper section and a softer formation below. The new 6-3/4 inch tool was run in the test well and drilled DV tools, cement, float collar, and float shoe, then penetrated the hard and abrasive formation. The hammer drilled 912ft with an ROP of 10.5 ft/h with a pure drilling time of 87 hours. The ROP increase is around 30% for the same depth and formation with less WOB and RPM. Drilling efficiency was increased in the top section with less WOB and RPM compared with the same formation and depth of an offset well section drilled with hybrid bits. The differences of the wells in the hard abrasive formation thickness, bit type, BHA, bits dull grading, and RPM are studied. The tool performance evaluation and lessons learned from optimization and trial tests are summarized. The future direction of this work is also discussed.
Mixed Preformed Particle Gel System for Water Shutoff in Fractured Carbonate Reservoir
Authors: Cao Dongqing , Almohsin Ayman , Han Ming , Al-Harbi Bader 
Published: February 2023

AbstractWater shutoff from production well using particle type material is a great challenge due to the complex pressure and flow distributions near wellbore. A mixed preformed particle gel (PPG) system was developed to enhance the performance for water shutoff in fractured carbonate reservoirs. The PPG blocking behaviors in fractures and methods to improve the water flush tolerance were investigated. PPG strength dominated the water shutoff performances in fractures. PPG with medium to high strength showed better performance than other samples due to the well-adjusted properties in blocking and flush tolerance. For the selected PPG, 30 mesh sample showed the best blocking performance among single mesh samples from 20 mesh to 80 mesh in the fractured artificial metal plug. Using 30 mesh sample as base sample, the 30 mesh and 40 mesh mixture with weight ratio 2:1 produced highest pressure build-up in two-size PPG mixtures. Further increasing the particle size distribution by combining various particle size PPGs, the blocking performance was improved. An optimized combination of 30 mesh, 40 mesh, 50 mesh and 60 mesh particles with weigh ratio of 4:2:1:0.25 was developed. In addition, a fiber material, added in the PPG, significantly improved the water flush tolerance of the PPG pack. A particle size combination of PPGs mixed with the fiber material generated better blocking performances than the other combinations. This study provides insights on packing behavior of deformable gel particles in fractures with a practical PPG based system for water shutoff treatments.
Successful Development of the Deepest Oligocene Syn-Rift Sediment in the Malaysia-Thailand Joint Development Area: Is the Deeper Zone Our Future?
Authors: Setiawan Avidianto Suryo , Simatupang Martin Hendra , Rachmadi Arif , Apiwathanasorn Sippakorn , Moh. Said Samsul Bari 
Published: February 2023

AbstractField X, located in the offshore Malaysia-Thailand Joint Development Area (MTJDA), comprises multiple stack gas reservoirs with a combination of trap styles. This paper highlights the challenges and lessons learned in successfully developing the deepest Oligocene syn-rift sediment in the MTJDA, which was initially discovered by the one appraisal well drilled in 2010. A further comprehensive evaluation was performed to justify the deepening of development drilling in 2019 (as appraisal cum to development) and 2021-2022 (as infill wells) with promising results.The discovery of hydrocarbon resources in the deepest Oligocene syn-rift sediment at MTJDA was part of an appraisal program by deepening the development well. The two wells discovered and proved the presence of multi-stack gas sands in this deepest section (3800-4000 mTVDSS). The clastic sediment deposits in a fluvio-deltaic system. The reservoir properties of this syn-rift sediment are better than the early post-rift sediment (early Miocene). The production test confirmed the initial gas flow rate of about 15 MMscfd. A comprehensive analysis was performed to evaluate a sizeable volume before more development wells were proposed for this deepest sediment.The initial understanding of Late Oligocene syn-rift sediment was very minimal at the beginning of the project. One of the neighbouring well information suggests lacustrine delta environments based on core data. However, a fair-quality seismic amplitude shows a broader channel belt (over 3km width) which usually exists in the braided stream. In view of the two appraisals cum to development wells' successful discovery, more than five wells were proposed to penetrate this zone as a deepening target from the existing discovered zone. The fit for purpose well designed with a monobore concept, was selected. Upon completing the development drilling with denser well spacing, it suggests the discontinuity of blocky sand presence with multiple fluid contact (stratigraphic compartmentalization), which is usually found in narrower channel reservoirs at the deltaic system rather than the braided stream. The good reservoir properties observe from the open hole log, formation tester, and production test. The success story of these wells opens future opportunities to plan more deep well to develop Oligocene sediment, which prove to be a good hydrocarbon producer.This paper updates the previous understanding of geology, such as the depositional environment, and the understanding of reservoir productivity of the Oligocene sediment in MTJDA. It also proved sizable reservoir quality with extensive lateral presence and good productivity. Hence, the company foresee a promising future from this deep reservoir to prolong its long-term development plan.
Research and Application of Big Data Production Measurement Method for SRP Wells Based on Electrical Parameters
Authors: Chen Shiwen , Deng Feng , Chen Guanhong , Zhao Ruidong , Shi Junfeng , Jiang Weidong 
Published: February 2023

AbstractWell metering is an important part of daily oilfield management. For wells in a block, production metering can help reservoir managers fully understand the changes in the reservoir and provide a basis for reservoir dynamics analysis and scientific field development planning. For single-well metering, accurate producing rate can help oil well operators optimize the well production system, improve the efficiency of oil wells, and even discover abnormal conditions in oil wells based on changes in production.In order to obtain accurate well production, over 300 SRP wells in an experimental area of an oil field in northeastern China are tracked and measured in this paper. Easily available continuous electrical parameter data (including electrical power, current and voltage) and real-time output of the wells were selected as training parameters. We separated the SRP well electrical curves and corresponding real-time production data into a set of samples by one-stroke time, and obtained a total of 200,000 valid samples. The production status of the pumping wells was classified by deep learning, and the electric curves were Fourier transformed to extract statistical features.Then, we performed deep learning on these samples, using production parameters as input vectors and well fluid production as output results. Finally, good results were obtained by training and a model for calculating SRP well production based on big data was developed. The model was used to calculate the production of SRP wells in an experimental area of an oil field in northeastern China and compared with the actual production data. For low-producing wells with daily production less than 6 m3, the error of the model was less than 0.5 m3 /d, and for wells with daily production greater than 6 m3, the relative error of the wells was less than 10%, which met the expectation of managers. Compared with the methods mentioned in this paper, the currently used measurement methods, such as flowmeter measurement and volumetric measurement, have limitations in terms of instrumental measurement range and real-time measurement, respectively. In addition, both of these methods increase the construction cost of flow measurement systems.The big data production measurement model provides operators with a method for optimizing the production system of oil wells and also provides signals for early warning of oil well failures. This method can help managers achieve cost reduction and efficiency increase. The processing and application methods of electrical parameters in this paper can also provide ideas for production prediction of PCP o ESP wells.
Research and Application of the Comprehensive Corrosion Prevention Technology for Offshore Thermal Wells in Bohai Oilfield
Authors: Wang Hongyu , Han Xiaodong , Wang Qiuxia , Zhang Hongwen , Liu Hao , Wang Cheng , Zhang Hua , Dou Peng , Wen Jia 
Published: February 2023

AbstractMulti-component thermal fluid stimulation has been conducted in Bohai Oilfield for about ten years and at the early stage of the pilot, the corrosion of the thermal fluid injection tubing is severe with the existence of the oxygen and the carbon dioxide under high temperature conditions, which result in damage of the insulation tubing, increase of the production cost and even unwanted workover.For solving the corrosion problem and extending the working life of the tubing, the corrosion mechanisms is researched and analyzed at the first place. XRD and SEM is applied for analyzing the corrosion product. The results show that the corrosion is mainly caused by the high temperature carbon dioxide and vestigial oxygen. The high fluid flowing velocity and variable inner diameter of the insulation tubing also accelerate the corrosion process. Then, further study of corrosion behavior and corrosion prevention technology are proceeded.Corrosion behavior study is carried out through indoor experiment. The results indicate that steel corrosion rate would reach the maximum value at the temperature of about 80 centigrade. At low temperature range, the corrosion is mainly dominated by CO2, and at high temperature range, the corrosion is mainly dominated by O2. For O2 corrosion at the conditions of about 370 centigrade and 15MPa, if the O2 concentration is below 1000 ppm, the corrosion rate would be lower than 0.076mm/a and when the concentration reaches about 1%, the corrosion rate would rapidly increase to be about 2.38mm/a. Based on the analysis above, high temperature corrosion inhibitor is researched and selected. The inhibition efficiency of the optimized inhibitor could be higher than 90% which could meet the technical requirement for corrosion prevention. For further increasing the efficiency of the corrosion prevention, tubing with higher corrosion resistance is used. For the existence of the CO2 and O2 in the inner tubing during the injection process, the selected corrosion inhibitor is injected before the thermal fluid for forming the protective film at the inner side. And for the annular space, high purity Nitrogen which is higher than 99.9% is injected for lowering its O2 concentration.Till now, the comprehensive corrosion prevention technology has been applied for field test for nearly 30 well times. The corrosion problem has been greatly solved, the corrosion rate is lower than 0.1mm/a and no severe corrosion occurs during the thermal fluid injection process. Its successful application would provide a guidance and technical support for the subsequent offshore thermal exploitation.
Rock Physics Applications on Seismic-Based Reservoir Characterisation of the Gas Fields, Offshore Malaysia-Thailand Joint Development Area
Authors: Boonyasatphan Prat , Akarapatima Thanyanat , Poonyachotwanich Yanika , Majikol Piyanuch , Taha Mohi Eldin Sami Mohamed , Diyana Hafit Husna , Abd Mutalib Mohd Al-Amin 
Published: February 2023

AbstractThe A-J gas field requires the next phase of the drilling campaign, and identifying the new targets is required. So far, target identification is based on anomaly detection of seismic attributes together with geological concepts. The new thorough rock physics analysis is conducted to get a better understanding of rock within the area and, therefore, a better attribute selection for target identification. The rock physics analysis provides an insight of rock properties within the area and reveals the relationship between rock and seismic. The analysis also provides a better understanding in terms of geology. The analysis has suggested that the reservoir can be properly identified by using the far-angle stack related attributes. This includes relative acoustic impedance (rAI) and an extended elastic impedance (EEI). Validation of the attributes to the well has shown that the two attributes can help identify and define the reservoir within the area better. And the newly identified target from the study resulted in a better well targeting.