bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific Procedure for an Offshore Chemical EOR One Spot Pilot in a High Salinity High Temperature Environment
Authors: Morel Danielle , Al-Amrie Omar , Delattre Eric , Cordelier Philippe , Greder Hugues , Rivero Mayela , Romero Carolina , Bursaux Romain , Peltier Sophie , Levitt David 
Published: September 2016

Abstract
In 2014, Total performed a surfactant-polymer one spot pilot offshore to test the effectiveness of inhouse developed surfactant molecules to mobilize trapped oil. This paper describes the deployment of this pilot, as a key step of the derisking roadmap of chemical EOR under the harsh salinity and temperature conditions of Middle East carbonates. During several years of R&D and focused studies on this field of the Emirates, a surfactant polymer formulation has been developed able to achieve very low residual oil saturation at core level. The question of testing the formulation in the field has been addressed in parallel to the laboratory work, through extensive surface and subsurface integrated studies, in order to define which type of pilot would be the more suitable.
The paper addresses several aspects: –Pilot type selection from a geosciences point of view and versus objectives and information provided: where, how many wells, time response, cost–Monitoring needs: base line establishment, injection and production follow up,–Surface issues related to the pilot in this offshore context: injection and production top side facilities–Chemical logistics when part of the formulation is a R&D chemical, to be manufactured on purpose, and imported in due time, including the choice of premix versus on line mixing products–Management of a pilot as a project but still with the specificities of derisking and qualifying a technology on a mature field (from preliminary study to project execution)–Offshore concerns, with the added difficulty of a H2S environment
After a cautious analysis of the pros and cons, a one spot pilot has been sanctioned. The design of the pilot versus effective realization is provided, together with the decision tree that was constructed in order to face any operational issue. The paper emphasizes how a strong project management, and headquarters/operational team collaboration allowed completing a safe and successful pilot, ultimately achieving ultra low residual oil at the one spot scale.
The success of a pilot project is conditioned to the strict application of a rigorous methodology of study, validation, and execution, like any development project
Implementing Various Tactics to Overcome the Effects of the Big Crew Change
Authors: Kamble P. D. , Bagga P. S. , Kakade R. 
Published: September 2016

Abstract
Intelligently said by Albert Einstein, "The only source of knowledge is experience" is the basis of the imminent crisis faced in the industry unless proper steps are taken. Born during 1946-1964, baby boomers make up a major portion of the oil and gas industry who will be retiring in the next 5 years. This will change the entire demographic profile of industry leading to a change in the experience profile. Hence, once again reminding us to equip younger generation with skills from older fleet. At an age where development and advancement of technology such as hydraulic fracturing, casing while drilling and gas hydrates research is going on, technical talent is a treasure. Especially now when there is a threat of losing potentially talented amateurs due to lack of jobs, there is a need of knowledge transfer between these retiring veterans and young professionals in a company, within a restricted amount of time. If harnessed in the right way, the two generations can complement each other in creating the perfect team and work better in a multifaceted approach.
As mentioned, in today's scenario of hiring-firing cycles in the industry, the baby boomers might leave the industry facing with the problem of skill set gap. This issue is amalgamated by low representation of mid career employees, again owing to the firing tendencies of the volatile industry. Although the impending doom of Big Crew Change has been known for quite some time, no proper solution has been found. The authors of this paper have identified few effective methods to strategize production and future growth. These strategies are synched with Oil and Gas industry and proposes to help in the following ways: To bridge skill set gapTo scrap outdated and complex technologiesTo transfer knowledge, digitize it and strengthen middle-career crewTo learn, capture and duplicate the knowledge before it is lost
Complementing each other's working styles and various kinds of knowledge, together, the various generations can bridge every gap in the long run. The paper will talk about all the steps that can be taken by companies in the next 3-5 years to deal with the big crew change and being a one of a kind industry what we can do to retain the unique and brilliant expertise. Authors provide a "Knowledge Security" triangle which will benefit all companies to solve this issue. The scenario based case study of India and USA has also been discussed.
Characterizing and Predicting Reservoir Quality in Argillaceous Sandstone Reservoirs, Offshore Brunei
Authors: Saha Sourav , Espejo Irene , Gelinsky Stephan , Keym Matthias , Naeth Jochen , Jäger Günter 
Published: September 2016

Abstract
Prospects near existing infrastructure can be economically attractive; however, reservoir quality prediction is crucial to de-risk opportunities further from infrastructure including deeper, high pressure and high temperature (HPHT) opportunities. Understanding shallow reservoir properties is important and needs to be translated to predict the deeper reservoir quality where compaction and cementation often have a negative impact on reservoir quality.
The Baram and the Champion river systems deposited sediments offshore Brunei in various depositional environments, with multiple pairs of sandstone-siltstone reservoirs and bounding mudrock facies. The observed variation in the composition of reservoirs is an indication of a slight difference in provenance between the two river systems; however, the different is texture is an indication of length of sediment transport.
Qualitative and quantitative petrographic information was collected from a large number of thin sections from eight representative wells. Based on the overall sedimentary structures and textures observed in thin section, four (4) sandstone and three (3) siltstone petrofacies were described. Detailed point-count (300 counts per thin section) data was collected from these sandstones and siltstones for compaction and diagenetic modelling. Present day intergranular volume (IGV), macroporosity and cement types were quantified from thin sections. These parameters were subsequently calibrated for forward-modelling, using burial histories at each well location. The model was then blind-tested in order to verify the expected present day prospect porosity and permeability ranges. The resulting model was correlated with petrophysical well log data, to allow connecting rock properties to prospect seismic responses.
For the first time, a comprehensive offshore Brunei sedimentary petrology database was assembled covering major depositional environments from both dominant river systems. This database was compiled in a reservoir quality modelling software, which will allow for burial history-based reservoir quality predictions, both regionally and at prospect locations.
Petrophysical Characterization of Tight Sands in Granite Wash, Anadarko Basin
Authors: Agarwal Aditya , Rai Chandra S. , Sondergeld Carl H. , Truax Jerome 
Published: September 2016

Abstract
The Granite Wash formation is made up of arkosic detrital material and is deposited as a series of overlapping submarine fans. These tight gas sands have very low porosity (&lt;8%) and permeability (&lt;.001 md). The Granite Wash contains upto ten discrete production zones. The recent drilling activity in Granite Wash play has increased substantially in the oil and condensate rich zones. These formations are highly complex and heterogeneous which poses a major challenge in characterizing them. Identification of best reservoir rocks in the Granite Wash has long been a piece of puzzle.
Petrophysical measurements (porosity, mineralogy, mercury injection capillary pressure, permeability, NMR) have been performed on 115 ft of core from a well located in the Wheeler County. The core has been recovered from the Carr formation. The porosity in the formation ranges from 1.2% to 7.4% with an average porosity of 4.3±1.3%. The porosity of the samples increases with an increase in grain size. The mineralogy in the formation shows a wide variation and consists of quartz (24±8%), feldspars (50±13%), clays (23±14%) and carbonates (3±6%). The rock quality is severely affected by the pore filling chlorite (~20%) in the formation. The MICP and NMR data shows bimodal distribution of pore throat size and T2 distribution, indicating presence of two types of pore system.
We utilized principal component analysis and K means clustering technique to identify different clusters of similar petrophysical properties. Based on our clustering analysis we identified three rock types in the Carr formation. A unique mercury injection capillary pressure curve was observed for each cluster. The thin sections support the different rock types in the Carr formation.
The variable grain density (2.62 gm/cc to 2.78 gm/cc) and presence of chlorite (~20%) complicates the estimation of porosity from neutron and density logs. Also, the presence of K feldspar (0 to 12%) forbids the use of gamma ray log in estimation of clay content in these formations. Based on the results of the core analysis, a method to identify the best reservoir rocks from conventional well logs is suggested.
Source Parameters of Repeating Microseismic Events During Hydraulic Fracturing Operations
Authors: Chao Kevin , Prieto German A. , Du Jing 
Published: September 2016

Abstract
A complete microseismic event catalog with accurate source parameters can lead to a more thorough understanding of the temporal and spatial variation of stress during hydraulic fracturing operations. We detect, locate, and characterize repeating microseismic events by determining their source parameters such as magnitude, stress drop, and rupture size, and analyze the continuous microseismic data recorded by one borehole array during a hydraulic injection process. With an existing microseismic event catalog, we first re-calculate accurate moment magnitude and stress drop using estimated source spectra for all events. In addition, we detect and locate smaller events that show only clear S-wave arrivals using a template-matching and waveform cross-correlation technique to identify repeating microseismic activities. We obtain the template waveforms by stacking similar waveforms from repeating microseismic families. Among the ~1300 re-computed events, the moment magnitude calculated from the P- and S-waves spectra analysis ranges between Mw −1.5 and −3.5. These events are located within a 700m by 200m area as much as 250m deep. Our results indicate a fault radius on the order of one to six meters and fault slip between 10−5 to 10−3 cm around the fracturing region. In addition, using a matching-filter technique, we detect and locate low signal-to-noise ratio events that we consider repeating microseismic events. Our observations indicate that most repeating families occur at later times in shallower layers. Also, we observe a strong magnitude dependence of the stress drop, with larger magnitude events exhibiting significantly greater stress drops than smaller ones, in contrast to tectonic events in California or Japan. Our estimations of source parameters provide a key to a more in-depth understanding of the relationship between hydraulic fracturing and microseismic activity.
Development of a Chemical Flood Simulator Based on Predictive HLD-NAC Equation of State for Surfactant
Authors: Jin Luchao , Li Zhitao , Jamili Ahmad , Luo Haishan , Delshad Mojdeh , Lu Jun , Shiau Ben , Harwell Jeffrey H. , Rui Zhenhua 
Published: September 2016

Abstract
Chemical flood reservoir simulators developed based on component partitioning model or empirical phase behavior model lack the effects of physical properties such as surfactant structure and oil properties i.e. equivalent alkane carbon number (EACN) on microemulsion phase behavior. Hence, these simulators have limited function in helping formulation design. A typical empirical microemulsion phase behavior model is the Hand's model that is used in UTCHEM, a benchmark chemical flood compositional simulator. However, it needs several matching parameters to fit phase behavior experiments and requires iterative calculations to solve phase compositions. Therefore, it is desirable to develop a chemical flood simulator with a more efficient and physics-based phase behavior model.
This work incorporates a physics based HLD-NAC equation of state (EOS) into UTCHEM. A non-iterative flash calculation algorithm based on HLD-NAC microemulsion EOS is developed, which uses simple equations to represent plait point, binodal curve, and tie-lines. Input model parameters include quantitatively characterized physical properties, such as oil EACN, reservoir temperature, surfactant structure properties (head area and tail length), and optimum solubilization ratio. Therefore, the effects of these parameters on oil recovery can be systemically studied. Coreflood simulation results are validated against the Hand's model.
Compared to the Hand's model which requires at least 5 matching parameters and with limited predictability, the HLD-NAC EOS can reproduce microemulsion phase behavior with surfactant tail length as the only fitting parameter. Comparing coreflood simulations using the HLD-NAC model and the Hand's model shows that the same oil recovery curves are obtained when slug at optimum salinity is injected. However, for corefloods using a salinity gradient design, HLD-NAC model predicts higher oil recovery than the Hand's model. The reasons for the differences are analyzed by examining the simulated solubilization ratios and ternary phase diagrams at different salinities. Moreover, numerical experiments show that the HLD-NAC model improves the phase behavior computational efficiency by approximately 65%. The effect of live oil at reservoir pressure is also investigated. Results indicate shifted optimal salinity and solubilization ratio due to solution gas and pressure lead to larger microemulsion bank.
Owing to the physical significance, simplicity, and computational efficiency of the HLD-NAC EOS, this novel chemical flooding simulator proves to be a fast and promising tool to speed up surfactant screening process and helping chemical formulation development and injection designs.
First Ever 14 ¾ X 17 ½-in Rathole Elimination in Gullfaks Satellite Using Downhole Drilling Mechanics and Dynamics Tool and Latest Features on PDC Design
Authors: Khalil Haitham , Blackburn Jason , Harmer Richard , Skofteby Geir , Kallestad Richard 
Published: September 2016

Abstract
The objective of this paper is to share the results obtained from in-depth analysis using a down hole mechanics and dynamics monitoring sub, which lead to the first successful Gullfaks Satellite 14 ¾ x 17 ½ -in Rathole elimination operation through challenging lithology.
Shallow gas is encountered in the Gullfaks South area at a true vertical depth of between 335-339m (from MSL), and a casing design incorporating a 16-in liner is utilized to isolate this interval. A 14 ¾ x 17 ½ -in section is then drilled to isolate weak and unstable formations, and in all previous wells this section was drilled with a two run strategy. The first run to drill to section target depth (TD) while hole opening, followed by a dedicated second run to open the rathole. An opportunity was identified to improve well construction performance by eliminating the dedicated run to open the rat-hole, and tailoring the bit design to overcome the challenging lithology and high levels of shock and vibration seen on offset wells.
Detailed pre-job planning and BHA design analysis was combined with new downhole technologies to overcome these challenges. Dual reamers were used within a Rotary Steerable System (RSS) BHA to drill the 14 ¾ x 17 ½ -in section and eliminate the rat-hole in one run. This innovative approach involved drilling to section target depth (TD) using an upper ball drop reamer, tool positioned 45 meters behind the bit for hole enlargement while drilling, and then pulling back to position the bit at rat-hole shoulder. At this point the upper reamer was de-activated and a lower on demand hydraulically activated reamer, mounted directly above the RSS was opened to eliminate the rat-hole. Due to excessive shocks & vibrations experienced on offset wells, a down hole drilling mechanics & dynamics sub was utilized to provide real-time information about downhole forces and BHA motions, combined with a tailored bit design to control depth of cut in sandy intervals. This unprecedented approach resulted in 2.5 days saving.
Evaluating and Optimizing Refracs - What the Diagnostics Are Telling Us
Authors: Leonard R. S. , Woodroof R. A. , Senters C. W. , Wood T. M. , Drylie S. W. 
Published: September 2016

Abstract
Refracturing continues to provide operators with the opportunity to add production at a fraction of the cost to drill and complete a new well. Various re-stimulation designs and diversion techniques are currently being utilized to maximize contact with previously un-stimulated rock. Optimizing this process involves evaluating all available diagnostic, pressure and production data and determining the optimum design that maximizes recovery. This paper describes how these diagnostic technologies have been employed to evaluate and optimize refracs in four major North American basins.
The process of refracturing and recompleting wells continues to improve. Much of this improvement comes from the optimization of techniques through completion diagnostics. Diagnostics provide data that can quantify the amount of the lateral treated and the effectiveness of diversion. Operators are focused on bridging the gap between the completion methods commonly used at the time the well was originally completed and the methods of today. Application of completion diagnostics also assists in identifying opportunities to further reduce the cost of the project while achieving similar results. In this study, proppant tracing followed by spectral gamma ray logging was employed to evaluate the effectiveness of the refracs, the extent of new rock contacted, the benefits of reperforating, and various diversion methodologies.
Diagnostic results from 121 vertical (34) and horizontal (87) refracs covering 16 different formations and 26 different operators were analyzed and compared based on stimulation effectiveness and performance. The wells were then grouped by well type, formation and the basic refracturing technique that was utilized. In addition to the macroscopic data interpretation; four case histories are presented from the Barnett Shale, Permian Basin, Eagle Ford, and Haynesville. These case histories include before and after reservoir production matching with fracture half-length and effective conductivity calculations along with the diagnostic analysis of new and existing perforation coverage, diversion effectiveness, and ultimately the % incremental estimated ultimate recovery (EUR).
Wolfcamp Completions: Lessons Learned through the Implementation of Completion Diagnostics to Optimize Existing Drilling and Stimulation Practices
Authors: Warren Mark N. , Dempsey Christopher J. , Woodroof Robert A. 
Published: September 2016

Abstract
The lessons learned in the Wolfcamp formation from utilizing completion diagnostics have greatly increased productivity over the years. By employing proppant tracers and subsequent spectral gamma ray logging, along with water-based and oil-based chemical tracers and subsequent produced fluid analysis, trends have been observed, and, where appropriate, changes have been made to the wellbore design, landing interval and subsequent frac design. Throughout the changes, completion diagnostics were utilized and referenced to hydraulic fracturing characteristics, drainage patterns, wellbore spacing, geologic identifiers and overall completion effectiveness, as measured by post-stimulation well performance.
This paper reviews many of the insights that have been developed through the use of completion diagnostics in the Wolfcamp formation, as revealed by an extensive database of completed wells. These insights have led to completion optimization, improved well architectures, production enhancements and field-wide cost reductions. The lessons learned should prove useful for both established Wolfcamp operators as well as those new to this play.
A SMART Framework for Contextualization of Drilling Data for Supporting Drilling Workflows
Authors: Arumugam Sethupathi , Gupta Sanjay , Rajan Shebi , Ranjan Rajeev 
Published: September 2016

Abstract
Realtime operations generate huge amount of data that are stored as chunks in the WITSML data standard. Current WITSML model (version 1.4.1 or prior versions) does not provide enough flexibility to categorize channels. It is a challenging feat for users to dig through WITSML log object from a specific hole section or from a specific rig activity to zero in on any specific time frame in the aftermath of a NPT. This paper proposes the framework for a smart framework that organizes drilling data based on the rig activity within appropriate hole section without making any changes to the WITSML standard. This framework identifies rig activity, macro states and well events.
This framework proposes a logical hierarchical tree structure starts with parent node based on hole sections, WITSML objects are aligned with corresponding hole sections. Each hole section is further divided into child nodes based on rig activity. Realtime workflows are aligned to the corresponding rig activity e.g. ROP optimization, wellbore stability workflows are aligned to drilling activity parent node. Based on this parent child relationship user can retrieve any Hookload sequence for any tripping operation, for any hole section without any hassles. Any changes within the framework, updated by the user, for the current activity will be auto adjusted for subsequent activities within the tree structure. Identifying risks and events from the historical wells for future analysis is often viewed as a time consuming task; this solution aligns risks and events for each hole section under individual rig activity making it easier to retrieve it from historical wells during well planning. Along with logical organization of drilling data, this framework also offers an Operational Time Vs Depth plot that provides a Bird's Eye view of the entire well operations.
This solution can be used as a comprehensive logical structure for managing realtime and historical data from configuration to operational execution. Managing of historical and offset wells is simplified at the click of a button compared to the conventional method of data search.
The workflow provides the flexibility for minimizing user intervention by eliminating the need for repetitive configuration activities for each hole section within the wellbore. This workflow can be effectively used by a novice or an expert user.