bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Method to Forecast Reservoir Performance during Immiscible and Miscible Gas-Flooding via Transfer Functions Approach
Authors: Sayyafzadeh Mohammad , Mamghaderi Azadeh , Pourafshari Peyman , Haghighi Manouchehr 
Published: January 2012

Abstract
In order to improve oil recovery during gas flooding, it is crucial to afford an accurate estimation of future performance. So far, different approaches have been developed to present forecasting. The most common reservoir simulator, grid-based, which has the highest accuracy, suffers from some weaknesses; time-consuming computation and also need for large quantity of data. Sometimes, a quick overview of reservoir performance is adequate or all required data are not accessible. Therefore, in this study a fast simulator is introduced to provide a quick overview with the minimum amount of data.
In this study, the development of a method based on transfer functions (TF) is presented to model immiscible and miscible gas flooding. TF is a mathematical representation in Laplace domain which demonstrates the relation between the input and output signals of a system. In the proposed method, reservoirs are modeled with a combination of TFs. The order and arrangement of the TFs are chosen based on the physical conditions of the reservoir which are ascertained by checking several cases. Injection and production mass rates act as input and output signals respectively. TF parameters are calculated using history matching. Also, a fractional flow model is introduced and coupled with the TF system to obtain oil production rate as the final output.
In an attempt to validate the approach, it is required to compare the results with the grid-based method. Six different synthetic cases are constructed and used to validate the developed approach. The results state a good agreement with those obtained from the numerical simulators.
This approach is a quick way to predict gas flooding performance with minimum amount of data, production and injection rates data are the only requirements. It can be a new window for the future of fast simulators. It provides estimations with plausible certainty. On the other hand, the analytical solution of method enables its utilization in finding optimum rates for gas injection in a short period of time. The method also presents some key parameters such as well connectivity. It is fair to state that the use of the model is limited to situations when a rapid estimation is looked for and/or adequate data is not accessible.
Fully Automated Fluid Level Measurement Tool
Authors: Sam G. , Kaestenbauer M. , Burgstaller C. , Chevelcha E. 
Published: January 2012

Abstract
The fully automated fluid level measurement tool was developed recently. The paper describes the technical features of the tool and shows via case study the results of the field tests on various Electrical Submersible Pumps - ESPs and sucker rod pumps – SRP, running with and without Variable Speed Drive - VSD.
The unique feature of this system is its fully automated and purely electronic functioning. The measuring device is enclosed, mounted on the casing valve, has a pressure rating of 350 bar (5000psi) and works with zero emissions on the environment (no outlet of casing gas).
Compared with a conventional downhole pressure sensor, mounted on an ESP, the system is insensitive to high well fluid temperatures and simple to maintain due to its easy access on surface location. It additionally has a sampling rate of down to one measurement per minute. The measured fluid level data can be transmitted via SCADA system.
The measurement tool enables to run a pump in a more safe way. It can be used to avoid pump off conditions and the resulting equipment damage. It can also be used to control a VSD to keep the fluid level in a well at a specific depth to avoid bottomhole flow conditions below the bubble point pressure. Due to the availability of online fluid level data, all kind of pumps (e.g. ESP, Sucker Rod, PCP, Jet Pump) can be operated safely at more aggressive production rates in order to mobilize more oil.
Furthermore the vision and corresponding thoughts of acoustic well diagnosis, also a feature of the tool which is currently under investigation, are presented.
Failure Analysis and Consequent Process Improvements for a Down-Hole Intervention Tool
Authors: Fisher Jerry , Haq Mohammed A. , Bansal R. K. , Bailey Thomas F. 
Published: January 2012

Abstract
This paper describes development and testing of a new guide shoe mill (GSM) for intervention fishing services in conjunction with the well construction’s drilling hazard mitigation. Primary application of this mill is for milling guide-shoe left in the well by the solid expandable running tool system. The traditional milling direction is downwards. The new mill was designed to mill upwards in the reverse direction, thereby clearing the restriction and restoring the well bore casing drift internal diameter (ID). This paper covers development of guide shoe mill, failure analysis on a test well, and improvements done in various steps to prevent future failures. Use of Finite Element Analysis (FEA) models and extensive lab tests are also discussed.
The ability to maintain stabilization while milling in a high vibration environment and to remove cuttings to the surface were two major challenges. The guide shoe mill out tool provides stability, efficient well cleaning to restore casing drift ID, thus saving on non-productive time (NPT) and other drilling related costs. The study of failure prevention has lead to better technology applications and process improvements. Successful results obtained from lab testing (including test rig) lead to potential application in other areas such as selective section casing patch removal.
Generalization of Dual-Porosity System Representation for Hydraulic Fracturing–Stimulated Shale Reservoir (Part 2): Modeling, Simulation Workflow, and History Matching Studies
Authors: Du C. Mike , Li James 
Published: January 2012

Abstract
Recently, a new methodology has been developed to model hydraulic fracturing induced fracture network and simulate a shale reservoir as a dual porosity system. The reservoir geological and petrophysical data are integrated to build both structure and property models. Microseismic (MS) data are used to delineate stimulated reservoir volumes; event intensities are employed to estimate hydraulic fracture intensity. The fracture intensity is calibrated by using hydraulic fracturing job data and geomechanical properties through the fracture propagation mechanism.
As part one of this title in previous study, a theoretical framework generalization for the new methodology was introduced. Modeling and calibration of fracture network by stage, by well, and by well pad are discussed. A superpositioning technique is used to process the overlapping of MS mapping responses from different stages. Different fracture network geometry and average fracture width are evaluated. Various stimulated volume expansion models are investigated for proppant placement estimations and fracture conductivity distributions. A procedure is also introduced to build a simulation model when MS data is lacking by utilizing treatment data, geomechanical parameters, and user experience on estimated stimulation volume configurations. In this paper, that framework generalization is updated with new analysis. We focus on details for implementation of the methodology, modeling workflow, and stepwise procedure. The process is comprehensive, giving full consideration to shale reservoir integrated modeling, data input, fracture network geometry configuration, intensity calibration, and calculation of dual-porosity model parameters for reservoir simulation and other fracture network properties.
This extended methodology and workflow can be applied to single well and multiple-well modeling when the well drainage volumes are interconnected. It provides an effective means for modeling and simulation study as well as history-matching calibration of stimulated shale gas reservoirs. The new modeling methodology was applied to a Barnett shale field case, and sensitivity and history matching analyses were carried out.
Utilizing Gross Heating Value Management in Field Development Planning
Authors: Wiboonkij-Arphakul C. , Tsai Ing Jye , Jablonowski C. 
Published: January 2012

Abstract
This paper discusses the challenges of integrating into an existing gas field a marginal field with poor gas quality that would otherwise be left stranded.
To prepare for the poor quality gas, this study added gross heating value (GHV) to the traditional scheduling analysis to ensure that the quality of sales gas blended from various fields would always meet specifications. The addition of GHV to the traditional scheduling analysis required devising a GHV forecasting method, creating a GHV management procedure, and implementing a new revenue allocation method. Each of these innovations required specific tasks. Examples of these tasks and their challenges are presented in this paper.
Coiled Tubing and Jointed Tubing Hybrid-String Well Intervention: Design, Testing, and Case History
Authors: Ehtesham Asif , Howard Robert , Lindsay Sharlene 
Published: January 2012

Abstract
The decreasing frequency and size of new oilfield-reserve discoveries and an increased demand for energy is forcing industry professionals to find more creative methods of extracting every drop of oil possible. Pinpoint stimulation is one of the processes that enables service companies to target smaller plays with treatments customized to their specific characteristics.
Throughout the ongoing evolution of this process, improvements are constantly being made to enhance the treatments. One of the latest improvements is the introduction of a coiled tubing (CT)/jointed tubing (JT) hybrid unit that combines the advantages of CT’s continuous movement with the rigidity of JT. For extended-reach horizontal sections, the hybrid-string hydraulic workover (HWO) jack supplies the horsepower to push it to bottom while the depth-reaching capability of the JT greatly exceeds that of the CT, which can buckle and lock up before reaching total depth (TD).
The equipment consists of an HWO rig-assist unit, reel trailer with powerpack, HWO tower with tubing guide, CT (top), JT (bottom), and a bottomhole assembly (BHA). The BHA includes a new-style safety valve that protects the flapper from erosion during sand pumping and can be surface or remotely activated for positive well-pressure control.
The advantages of running this configuration include the capability to run larger-sized CT for higher flow rates and faster treatments of longer horizontals, as well as the capability to continuously forward or reverse circulate.
In addition, the hybrid allows the JT to be hydraulically disconnected at the BHA after treating, thus leaving it in the hole as a completion or velocity string. This new technology is proving to be a new game-changer in well intervention.
The Use of Combined Static and Dynamic Material-Balance Methods in Gas Reservoirs
Authors: Ismadi D. , Kabir C. S. , Hasan A. R. 
Published: January 2012

Abstract
Estimating in-place volume associated with each well, leading to estimation of total reservoir in-place volume, is the cornerstone to any reservoir-management practice. Yet conventional methods do not always lend themselves for routine applications, particularly when used in singular fashion. However, combining them on the same plot has considerable merit in that they converge to the same solution when material-balance-derived average-reservoir pressure is used.
This study presents a systematic procedure for estimating the initial gas in-place volume (GIIP) when real-time surveillance data of pressure, rate, and temperature are available at the wellhead. Specifically, we show that log-log diagnosis, followed by combined static- and dynamic-material-balance analysis, and transient-productivity-index (transient-PI) analysis lead to consistent solutions. Thermodynamic behavior of fluids is also explored to ensure that the converted pressures at the bottomhole and measured rates have consistency and accuracy for reservoir-engineering calculations.
Layered systems were selected for this study because they represent most situations. Two synthetic cases probed issues pertaining to average-reservoir pressure computation with the pseudosteady-state (PSS) approach, and two field examples validated the approach presented here.
Dual Eccentric Reamer BHA Solves Hole Opening Challenges and Conductor Sharing Pass through Constraints
Authors: Raziyev Mukhamed , Liang Qingjian Jim , Syaifullah Nalom , Lee Swee Lyn , Willis Simon , Tang Kien Hoe 
Published: January 2012

Abstract
PETRONAS Carigali and Schlumberger IPM have formed an alliance to develop a field in offshore Malaysia. Due to space limitations, a platform extension was installed to accommodate three additional conductor sharing wellheads (CSW). Project challenges include limited CSW pass-through, well collision risk, highly unconsolidated formations in the angle building section, directional control and shallow gas zones.
To avoid well-to-well collision caused by poor directional control, a pilot hole must be drilled under the conductor to provide good directional control in the unconsolidated sandstone. The pilot hole must also mitigate shallow gas risk. To achieve the reservoir hole size and accommodate dual gravel-pack completions, the pilot hole must be opened from 8–1/2" × 16" to allow subsequent hole section drilling.
The project team had to design a BHA that could efficiently deliver the objectives with minimal rig time. To solve the challenges a new hole opening methodology would be required. The pre-drill analysis included studies in: BHA durability/dynamic stability to ensure good hole quality; hydraulics and fluid dynamics to deliver proper cooling and hole cleaning; optimized combination of hole opening technologies. To reduce reaming runs/bit trips, a dynamic modeling system was employed to quantitatively analyze the interaction of various downhole tools and optimize the BHA configuration/drilling parameters.
The modeled dual eccentric PDC hole-opening BHA was run and successfully solved the challenges, mitigated risks and met the required drilling objectives for completing the six CSW wells. A post-drill simulation analysis was performed to analyze the dynamic downhole BHA behavior with the actual operating parameters.
The authors will explain how the BHA was developed and successfully used in the field to solve the unconsolidated formation challenge. Survey method and challenges of drilling through the conductor sharing wellhead are also discussed.
Challenges in Improving the Hydrocarbon Gas Recovery: Case Study Using a Carbonate Gas Condensate Field in Malaysia
Authors: Jalil Mohd Azran , Masoudi Rahim , Darman Nasir H. , Sofia Nor Zarith , Othman Mohamad 
Published: January 2012

Abstract
Initiatives on improved hydrocarbon gas recovery are usually facing challenges which are directly related to representative understanding of reservoir and fluid flow characterization as well as the depletion strategies. A field case study has been used as a platform to explain such challenges and the adopted integrated methodologies toward improving the hydrocarbon recovery from the field. Reliable water saturation modeling, validation of the production allocation, reevaluation of the trapped/residual gas saturation (Sgr), modeling of regional aquifer behavior and its support, connectivity and pressure communication among the fields, fluid contact movement, gas expantion, smeared oil rim and condensate drop-out within the reservoir and appropriate production scenarios (i.e., off take rate, strategy, etc.) are among the challenges.
This paper presents on methodologies how to manage the challenges in improving the hydrocarbon gas recovery (i.e., IGR) through an integrated subsurface-surface study for the evaluation of giving a gas reservoir second life i.e. field rejuvenation. The adopted methodology integrates both simple analytical approaches including the the material balance and volumetric assessment as well as the 3D simulation modeling to evaluate the reservoir performance and examine some of these uncertainties and challenges and subsequently identify the value of the field second life through the optimum prediction and production strategies. As the studied field is in pressure communication with neighboring fields in a mega platform carbonate build-up through a stronge regional aquifer, the results from an isolated model for the field showed to be unrealistic and, therefore, an integrated mega platform model is constructed for the purpose of the study.
The study integrates the 4D seismic results, regional aquifer and trapped gas saturation modeling, reservoir performance monitoring, and its application to obtain a better history matching results and reliable prediction strategy for recovery factor improvement. By incorporating the 4D seismic results and representative water saturation and residual gas saturation modelling, the resulting history matched model is significantly improved with less degree of uncertainty and it is believed to be more reliable to produce optimum prediction scenarios, which focused on recovery factor enhancement. Various prediction scenarios together with advanced modeling of the regional aquifer effect in a merged mega platform model have been examined using the final history matched model. By doing this, the field recovery factor is improved by 16% and thus giving the field the second live to continue its production.
Reservoir Characterization for Fracture Distribution Prediction and New Well Target Identification
Authors: Lefranc Marie , Farag Sherif , Li Bingjian 
Published: January 2012

Abstract
One of the main challenges in the fractured basement exploration and development is the identification of proper well targets with minimized drilling risk. The estimation of fracture porosity and permeability distribution in reservoirs with low matrix porosity is also very challenging as the production relies mostly on the complex fracture network. The proposed method aims at identifying the potential flow-contributing fractures, modeling accurately the fracture density in the interwell space, and finally, building a robust and well-calibrated discrete fracture network (DFN) that is used to compute porosity and permeability properties. This holistic approach integrates the latest technologies for interpreting borehole images, identifying open fractures, computing fracture aperture, and generating a DFN. It also includes at each step qualitative and quantitative analyses to optimize the choice of 3D parameters: seismic attributes and estimations of fracture length, orientation and aperture distribution.
Evaluation of The Potential of Microbial Restoration of Natural Gas Deposit with CO2 Sequestration by Investigating Indigenous Bacteria in a High CO2 Content Oilfield
Authors: Mori Ryo , Sugai Yuichi , Sasaki Kyuro , Fujiwara Kazuhiro 
Published: January 2012

Abstract
We are focusing on in-situ microbial conversion of CO2 that was injected into depleted oil reservoirs for CCS into CH4 by oil-degrading and H2-producing bacteria and hydrogenotrophic methanogens. Those bacteria are concerned to be affected under high CO2 condition, which causes pH reduction of the brine; therefore, we estimated the possibility of this microbial conversion process under high partial pressure of CO2 in this study by investigating the following: –The habitations of above bacteria in a high/low CO2 content reservoir–The pH reduction of brine under high partial pressure of CO2–Productivities of H2 and CH4 by indigenous bacteria of the high CO2 content reservoirs
Thermotoga sp. and Thermoanaerobacter sp. whose productivities of hydrogen from crude oil had been shown by Fujiwara et al.1) were detected as a dominant in the high CO2 content reservoir. Moreover, Methanobacterium sp. and Methanothermobacter sp. that are well known as hydrogenotrophic methanogens were also detected from the reservoir. These results indicate that the effective microorganisms for this microbial conversion process can inhabit reservoirs that stored with CO2 for CCS dominantly.
The pH of the brine including bicarbonate more than 0.1 mol/L can be maintained at 7.0 to 8.0, which was suitable pH for many kinds of microorganisms, even under high CO2 partial pressure such as 5.0 MPa, suggesting that this microbial conversion process can be applied easily on reservoirs whose brine is abundant in bicarbonate.
Enrichment culture experiments of the brine were carried out under high CO2 partial pressure (3.0 MPa) at 75ºC. Both H2 and CH4 production were found in not only the brine having the pH buffering action but also the brine whose pH was reduced significantly under high CO2 partial pressure; therefore, the microbial conversion process may be also expected in normal reservoirs that have poor acid neutralizing capacity.
Methodologies and Tools for Coalbed Methane (CBM) Field Development Planning Studies
Authors: Ryba Artur , Everts A. , Alessio L. 
Published: January 2012

Abstract
Resource plays such as Coalbed Methane (also called Coal Seam Gas) fields typically exhibit a number of unique characteristics that set them apart to other hydrocarbon accumulations. We will argue in this paper that as consequence, conducting effective field development planning studies for CBM resources requires adopting a markedly different approach to the ones typically followed with conventional oil and gas fields.
In contrast to traditional offshore plays, replete with a rich literature of best practices and adequate tools, coalbed methane field development planning typically involves very large areas and number of wells, hence a correlative abundance of (static and dynamic) data, but also displays an often surprising variability between neighbouring wells. This variability is the consequence of a high degree of heterogeneity present at a small (1’s-10’s metres) to medium (10’s-100’s meters) scale, notably for permeability, but also isothermal properties, gas content, and even net coal distribution and seam geometry for some plays.
This paper offers insights on integrated development planning methods, uncertainty management techniques and modelling workflows, accumulated through the experience of a number of CBM plays. Expected relationships and possible cross-parameter models for the key reservoir properties are discussed. The development of practical tools to characterise the reservoir properties, as well as the performance of different well and completion configurations, simulation, field development planning, all the way to ultimately assessing the economic potential of the play are also illustrated.