bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing Water Injection Efficiency in the Mature Windalia Oil Field, NW Australia, Through Improved Reservoir Surveillance and Operations
Authors: Haghighi M , O'Reilly DI , Hunt AJ , Sze ES , Hopcroft BS , Goff BH 
Published: October 2016

Abstract
This paper demonstrates how good technical evaluations and focused operational application can enhance the value of a mature asset. The Windalia reservoir underlies Barrow Island (BWI), situated 56 km from the coast of Western Australia, and has produced oil since 1965. Waterflooding commenced shortly after initial production, in 1967, and remains the main drive mechanism in the field today. Throughout the life of this onshore field, water injection and oil production have varied according to asset strategy and economic conditions. In this case study, we share how recent improvements made in the areas of Reservoir Surveillance and Operations activities have increased water injection efficiency and total oil recovery.
Through the use of new methods and workflows, the BWI Sub-Surface team was able to target specific areas of the field to distribute water to in order to increase injection and maximise oil production. For example, new workflows were built with the real-time PI monitoring system to analyse Pressure Fall Off (PFO) tests from each of the 147 waterflood patterns in detail. Capacitance-Resistance-Modeling was also leveraged to guide individual well target injection-rates. Operationally, several projects were also initiated to increase water injection into the right areas of the field.
The new Reservoir Management approach has significantly increased the volume of water being injected into the areas of need, supporting improved levels of oil production. For the first time in almost 10 years, the stream-day water injection rate has exceeded 90,000 bwipd. The results from PFO transient interpretation and pattern balancing proved effective in directing water to low-pressure, high-GOR areas of the field. They also provided valuable information about formation perm-thickness and skin. The phenomenon of water-cycling was also largely avoided, owing to close monitoring of production well tests and water injector transient surveys.
The present work addresses reservoir and operational aspects of Australia's largest active waterflood. The lessons shared are highly applicable to a low oil price environment, as they show how fit-for-purpose and low-cost acquisition of reservoir data can lead to improved field performance.
Predicting Reservoir Rock Mechanical Properties Directly from Sedimentary Characterisation
Authors: Liu Keyu , Wu Bailin 
Published: October 2016

Abstract
Twenty-nine core plug samples of a wide range of Uniaxtial Compressive Strength (UCS) values were investigated using a suite of techniques including visual inspection at meso-scale on hand specimens and thin sections, microscopic examination, Scanning Electron Microscopic (SEM) analysis, laser particle analysis and X-ray Diffraction analysis to characterize their compositions, texture and sedimentary properties. An intimate intrinsic link is noticed between sedimentary features observed at meso-scale and that at the micro-scale, both of which can be directly correlated to rock strength. It has been demonstrated that one can empirically predict the rock strength (UCS range) of rocks from an inspection of core plug samples. A Rock Property Index parameter which combines a number of sedimentary parameters is found to be useful in qualifying or ranking the rock strength (UCS) of the samples investigated. A set of criteria of sedimentary characterization is proposed for empirically estimating the rock strength of core samples including the lithological compositions, heterogeneities, cementation, quartz and clay contents, grain contact nature, grain size distribution and visual porosity. This method may be applied to describe cutting samples at rig-site to provide timely information of the strength of the formation rocks while drilling.
Predicting Shallow Marine Reservoir Heterogeneity Using a High Resolution Mapping Approach, Brigadier Formation, NWS, Australia
Authors: Ainsworth R. B. , Payenberg T. H. , Willis B. J. , Sixsmith P. J. , Yeaton J. W. , Sykiotis N. , Lang S. C. 
Published: October 2016

Abstract
Reservoir delineation and characterisation of the shallow marine Triassic Brigadier Formation (Fm.), northwest shelf (NWS), Australia is challenged by the thin-bedded nature of the reservoir. These reservoirs are generally below seismic resolution in stark contrast to the underlying, seismically well-imaged Mungaroo Formation fluvial channel belt reservoirs. In the absence of clear seismic definition of reservoir distribution, development of reservoir models for the Brigadier Fm. rely heavily on conceptual depositional models refined by reference to depositional analogues.
The Brigadier Fm. intervals currently under development in the Northern Carnarvon Basin are typically 120 m thick with overall 50–80% NTG. Strata in this interval are generally structurally inclined in tilted fault blocks and sub-crop an angular unconformity (IJU) with overlying sealing shales. Although the general geometry of the inclined strata is imaged on seismic, poor impedance contrasts do not allow definition of individual sheet-like, five to 10 m thick depositional elements or internal lithic variations that could be used to confidently target development wells. Thick stacked successions of thin reservoirs separated by shale produce correlation uncertainties between wells and make it challenging to predict spatial trends in reservoir quality. In order to better predict vertical and lateral facies patterns within the Brigadier Fm., a novel approach of reservoir mapping and model construction was developed that deterministically predicts reservoir distribution and connectivity based on conceptual depositional models.
A revised Brigadier Fm. stratigraphic framework was created across the sub-regional (88 km x 64 km) study area by integrating the latest sedimentology, biostratigraphy, chemostratigraphy and seismic data. Depositional models of the Brigadier Fm. were reviewed by re-examining core using a depositional-process classification that defined reservoir-element-scale bodies within correlated stratigraphic intervals. Two key depositional scenarios were developed; an asymmetrical, wave-dominated delta model, and an alternative fluvial-dominated delta model. The Mitchell River Delta, north-west Queensland, Australia, was used as a partial analogue to define shapes and scaling of the subsurface depositional elements and their internal lithic patterns.
The sub-regional model produced for the study was built in flattened stratigraphic space. Depositional geometries were extracted from this model and morphed into structured space over specific fields. The hierarchical nature of the model enables seamless analysis of exploration to development scale issues. The model is currently being tested by predicting and verifying the vertical facies successions for exploration, appraisal and development wells, and dynamic flow data from well tests.
Low Cost Strategy and Practice for Low Permeability Oilfields Under Synergetic Multi Disciplinary Systems
Authors: Liu He , Li Ying , Bao Shu Jun 
Published: October 2016

Abstract
As a systematic project and a new development mode, cost-effective development for low-permeability reservoir can be achieved via professional coordination of multi-disciplinary systems. It requires the removal of all unnecessary formalities and expenses, the exploration for gaps and critical weaknesses, the establishment of a strategic framework and organization of low-cost innovation, as well as the integration, conformity innovation and the process innovation, by liberating internal innovators and seeking for external innovators, and by conducting low-cost experiment and respecting the fundamental interests of employees.
The methods of implementation are as after mentioned: 1) to build a consolidated information platform combining by exploration, development and engineering technologies; 2) to upgrade the intensive drilling capacity and the reasonable casing structure; 3) to develop the overall fracturing technologies and advanced process techniques; 4) to enhance the optimized management and measures for day-to-day production; and 5) to contain innovations in enhanced management and system protection.
Focusing on the development of oil and gas resources with extra-low permeability, the appropriate processing plan can be established through synergetic coordination of multi-disciplinary, continuous innovation in techniques and management. The combination of the aforementioned facts forming combined forces to establish a comprehensive low-cost multi- disciplinary innovative system and the market competitive mechanism, to unify the underground natural materials and aboveground artifacts, and to realize the purposes of single well production enhancement and cost reduction.
A Case Study for Deriving and Calibrating Net Reservoir in Thinly Bedded Siliciclastic Formations: Brigadier Formation, Offshore Australia
Authors: Pillai Paul , Douglas Brian , Prabawa Hendrayadi 
Published: October 2016

Abstract
The Brigadier Formation is a thinly bedded reservoir that contains approximately 40% of in-place gas resource in Wheatstone field, which underpins the two-train Wheatstone liquefied natural gas (LNG) project in Western Australia. The development drilling campaign has recently been completed with three Wheatstone development wells targeting the Brigadier formation in the northern part of the field. Accurate and timely determination of net reservoir thickness is crucial not only for evaluating field volumetrics and performance, but also to support time-sensitive drilling decisions. In the case of two of the Brigadier wells, the decision to accept a development well location or move to a contingent well location was required within 72 hours of penetrating the reservoir with a pilot hole. Additionally, TD (total depth) decisions in the Brigadier Formation were made on the basis of real time kH (cumulative permeability thickness) evaluation from logging-while-drilling (LWD) logs and are essential for balancing well deliverability requirements with minimising risk of early water breakthrough by optimising standoff from the aquifer.
A fit-for-purpose approach to calibrate and evaluate net reservoir in the thinly bedded Brigadier Formation will be discussed. Several methods of net reservoir determination have been tested in the Wheatstone field. Standard resolution methods like density-neutron cross-over, and photoelectric factor, and high resolution methods like electrical image logs - water-based formation micro-imager (FMI) and oil-based new generation imager (NGI) - and LWD alpha processed density are compared against core-based sand counts to derive the most reliable and fit-for-purpose method of net reservoir determination. Mud-type, conveyance methods and borehole condition also impacts the results of net reservoir evaluation.
The results from a combined density-neutron-photo electric factor method was found to compare very well to core net reservoir and image log-derived net reservoir, across mud types, reservoir fluids and hole angles. It is locally calibrated and blind-tested successfully across different wells. The nuclear tools are logged in every well in the field so this method of calculating net reservoir could be applied consistently across all wells. An added advantage is that the evaluation of net reservoir is independent of porosity and hence, net reservoir will not need to change with different generations of petrophysical evaluation.
A Cellulose Fracturing Fluid with Instant Solution and No Residue
Authors: Hua Ming , Yongjun Lu , Baoshan Guan , Xiaohui Qiu , Wei Liu , Fa Yang 
Published: October 2016

Abstract
Tight reservoirs normally have production problems due to very low matrix permeability and different damage mechanisms during drilling, completion and stimulation operations. These reservoirs have small pore throat size with significant capillary pressure energy suction that imbibes and holds liquid in the capillary pores. Such residues from Guar after gel breaks cause formation damage and low conductivity, and it can significantly reduce well productivity even in tight gas reservoirs. This paper presents a new cellulose derivative of instant dissolution and free of residue. The field test results of the new fluid in tight gas reservoirs in China show importance of minimizing formation damage in a hydraulic fracturing stimulation. Otherwise, the well productivity improvement may not be achieved in the case of excessive residues into formation during hydraulic fracturing operations. A new fluid has been applied in 18 wells in western China and the results show that the new fluid was easy to prepare and rapidly dissolved with no "fish eye", this system can reach 97% of the peak viscosity within 2 minutes, and the surface tension of the gel breaking liquid is 18.44 mN/m. No residue was found after the gel was broken, its conductivity was improved, and the formation damage is less than 13% in the core test. Meanwhile it has excellent properties of proppant suspension. Gas production in multiple wells of the tight gas reservoir increased to 2.13×105 m3/d after stimulation with the new fluid, 4.2 times higher than similar groups of wells using Guar-based fracturing fluids.
A New Structural Geology Workflow to Expedite and Validate Seismic Interpretation in a Structurally Complex Area: A Case Study from Exmouth Plateau, Australia
Authors: Roy S. , Massara P. , Ellwood M. 
Published: October 2016

Abstract
The Exmouth Plateau is a subsided, stretched and rifted continental platform that forms the northern part of the Northern Carnarvon Basin off Western Australia's northwest coast. The plateau is bound on three sides by oceanic crust and consists of more than eight kilometres of Palaeozoic to Mesozoic sediments (Exon & Willcox, 1978). Due to its geological history, the area presents significant structural challenges for interpretation and prospect evaluation. A new structural interpretation workflow has been developed, leveraging the efficiency of working in one single geoscience platform. The workflow reduces interpretation time and improves accuracy compared to traditional interpretation approaches. A significant advantage of this approach is that a structurally validated framework model is one of the primary outputs.
Structural interpretation from seismic data is one of the most important steps in understanding the subsurface. Geoscientists spend a considerable amount of interpretation time picking faults and horizons from seismic data to understand the subsurface structure. A traditional interpretation workflow, commonplace in the oil and gas industry, is to consecutively investigate separate 2D sections and subsequently combine the interpretations to build a 3D picture. This limits the understanding of the subsurface geology in highly faulted, structurally complex areas.
This study involved the application of a new workflow for producing a structurally validated interpretation on 3D seismic data from the eastern part of the Exmouth Plateau. This workflow incorporates seismic preconditioning, fault framework modelling, structural reconstruction and structural analysis techniques to validate the interpretation (Figure A––1). By constructing framework models of the data it is possible to visualize the interpretation in the richness of 3D. This ensures a valid interpretation of the subsurface geology and is critical for subsequent decision-making processes, such as prospect maturation or well-planning. The final result is clean, faulted seismic horizons and a highly accurate structural framework model. This model can then be used for fault throw analysis to understand growth faults and reactivation zones and investigate zonal fault juxtaposition for prospect analysis. The predictive capability of the framework model is key in ensuring exploration success in plays reliant on fault juxtaposition seal. Figure A-1A new workflow to produce structurally validated interpretations in structurally complex regions.
The framework model also becomes the foundation for geo-cellular modelling and further detailed analysis of dynamic behavior. This ensures the verified structural interpretation is carried throughout the entire exploration and production lifecycle.
The Right Stuff: Mitigating Human Factors — The Application of Crew Resource Management in Banyu Urip Drilling Operations
Authors: Morris W. C. , Wright R. A. , Ehrmann D. J. 
Published: October 2016

Abstract
Recent discussions and publications in the oil and gas industry (OGP 501 2014, OGP 502 2014) identify the significance of human factors in industry incidents (personnel safety, process safety, environmental, procedural discipline, etc.). Human factors are generally regarded as human performance limiting factors that, left unchecked, can lead and have led to high potential/high consequence events. Human factors include, but are not limited to, fatigue, stress, task overload, complacency, distraction, cognitive and physiological limits, as well as attitudes shaped by workplace/societal culture, education, and motivation. ExxonMobil Cepu Limited's Indonesia Drill Team (EMCL-Drilling) recognized that in order to achieve perfect or near perfect operations, including a completely hurt free and spill free environment while significantly improving performance efficiency, there needed to be a step change in the understanding and mitigation of human factors in its Banyu Urip drilling operations. EMCL-Drilling, in conjunction with PT. Ponco Oilfield Supplies & Services and Check-6, Inc. (Check-6), facilitated a 14-month, 2-rig program to assess and improve human factors awareness and modify team behaviors using Check-6's Performance Excellence® curriculum. This included application of Crew Resource Management (CRM), Plan Based Execution® (PBE), and After Action Review (AAR) principles. CRM PBE-AAR is recognized as a component of Performance Excellence and High Reliability Leadership (HRL) and a proven method for High Reliability Organizations (HROs) to improve operational discipline and achieve perfect days in our industry. Ultimately, EMCL-Drilling's application of CRM PBE-AAR produced significant days of perfect HSSE and operational execution.
This paper provides background on initial workforce performance and behaviors, the introduction and continuous coaching and mentoring of CRM PBE-AAR, and the results achieved. EMCL-Drilling concluded over 20-rig months of operations with CRM PBE-AAR, with notable obstacles of language barriers and arduous rig moves in difficult terrain, where rigsite personnel and supervisors were assessed, human behaviors modified, and process controls improved with zero hurts, zero spills, and significant improvement in operational performance efficiency. As a result of workforce improvements and empowerment, new tools and technology were introduced to further ingrain learnings and capabilities. Rigsite teams demonstrated increased professional and personal pride in their work, taking ownership of processes, accepting responsibility and accountability for their actions and the actions of others, and most importantly developed a sense of empowerment knowing their voices and opinions were heard, respected, and acted upon. The culmination of these efforts resulted in EMCL-Drilling completing the final phase of its Banyu Urip drilling campaign completely hurt free, spill free, and with a perfect day efficiency of 95%.
Emerging Numerical Modelling Technique to Evaluate Asphaltene Inhibitor Efficiency During Entire Field Life
Authors: Yonebayashi Hideharu , Zhang Xiaohong 
Published: October 2016

Abstract
This work was motivated for establishing a robust asphaltene flow assurance engineering using asphaltene inhibitor to mitigate the risk of asphaltene precipitation in tubing. For this purpose, the best candidate was selected through asphaltene dispersant test (ADT). Furthermore, its inhibiting efficiency was evaluated by generating a numerical model. The purpose of this evaluation was to predict how it's efficiency varied during entire field life in which production condition changed in early and late life.
Through the two staged ADT, the best inhibitor IB-23 was selected from total nineteen samples. The IB-23 revealed high inhibiting efficiency more than 80 % at 200 ppm concentration and maintained its efficiency more than 70 % even at 10 ppm. Currently, any commercial software is not available for modelling of asphaltene inhibitor due to confidentiality for inhibitor's physical data. This study achieved to model inhibiting efficiency by treating inhibitor as pseudo-resin and/or pseud-component. It could be defined using limited physical data that was available in public accessible material safety data sheet (MSDS).
The numerical model was generated using cubic-plus-association (CPA) EoS together with the conventional fluid characterization to characterize the asphaltene crudes. This paper demonstrated that the numerical model expressed the inhibiting efficiency as size-reduction of asphaltene precipitation envelope (APE) and decrease in the amount of asphaltene precipitated. The model validity was checked by comparing with experimentally measured weight data of asphaltene deposits during the ADT. Assuming natural depletion, the APEs were compared with variation of vertical lifting curves (VLC) in tubing. Two VLCs were assumed to represent early and late field conditions (i.e. high wellhead/reservoir pressures and depleted ones). The no-inhibitor case revealed precipitating risk existed over most of the tubing section. In contrast, the inhibitor-dosed case could significantly reduce the risks in the early stage in particular. Even in the late stage, the risks could be minimized as the interception of VLC on the APE became shorter than that of the no-inhibitor case.
Asphaltene inhibitor is a typical counter measure; however, most of the applications are temporary relief. Through an entire field life, the production condition varies such as pressure decline, GOR increase, etc. Accordingly, efficiency of the inhibitor, once selected as the best, fades away. Then, another screening would be required to select alternative one that can adapt effectiveness to the new operating condition. This paper contributes to estimate its inhibiting efficiency during a whole field life.