bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Unique Grid-Block System for Improved Grid Orientation
Authors: Chong E. , Syihab Z. , Putra E. , Schechter D. 
Published: December 2007

Abstract
The grid orientation effect is a long-standing problem plaguing reservoir simulators that employ finite difference schemes. A rotation of the computational grids yields a substantially different solution under certain circumstances. For example, in a five-spot pattern, the predicted recovery, water cut performance and the locations of the fronts depend on the type of grid system used. A Cartesian grid with one axis parallel to the line joining an injector and producer gives a solution significantly different from a grid that has the axes oriented at 45° to this line.
The objective of this study is to develop a grid system that can improve the representation of the configuration, thus minimizing the grid orientation effect. This paper presents a method for reducing the effect of grid orientation on computed numerical results in finite difference reservoir simulation. This method involves using a unique grid-block assignment where rectangular grid blocks are interspersed with octagonal grid blocks. The boundaries are then populated with triangular grid blocks. Thus, the entire domain will consist of a "structured" grid block system referred to as the Hybrid Grid Block (HGB).
To test the viability of HGB, a finite difference IMPES-formulated two-dimensional black oil simulator was developed in this study, while retaining the familiar finite-difference discretization of the flow equations. Simulation cases were conducted to further examine the grid orientation effect in conventional grid block systems. Then, similar cases are run using HGB grid system. The outcome shows that HGB gives very close agreement between the parallel and diagonal grid orientation. This innovative grid block assignment will help to reduce the grid orientation effects compared to conventional grid block system.
New GTL Process - Best Candidate for Reduction of CO2 in Natural Gas Utilization
Authors: Suehiro Y. , Ihara M. , Katakura K. , Nakamura A. , Sakamoto A. , Kawazuishi K. , Kajiyama R. , Fujimoto K. , Ohnishi Y. , Okado H. , Shimizu T. 
Published: December 2007

Abstract
Japan Oil, Gas and Metals National Corporation (JOGMEC), which is a former Japan National Oil Corporation (JNOC), has been developing natural gas to liquids (GTL) conversion technology since the year of 1998 in collaboration with five private Japanese companies, namely; JAPEX Co. Ltd., Chiyoda Corp., COSMO Oil Co. Ltd., Nippon Steel Corp., and INPEX Corp. Our new GTL process is particularly effective when it is applied to natural gas feed stock containing 20-40mol% of CO2. It does not require the three expensive items; (1) an oxygen supply plant, (2) a unit for CO2 separation from natural gas, and (3) a H2 separation unit to optimize gas composition. The reduction of these facilities, which are indispensable to the conventional GTL process, would results in less CAPEX and OPEX.
For our new GTL process, the most preferable CO2 content in feed natural gas is around 30mol%. Therefore, in case that the CO2 content is less than 30mol%, some amount of CO2 can be supplied from other CO2 sources, such as flare gas, associated gas, remaining CO2 of EOR and exhausted gas from oil refinery and LNG plant.
This paper aims to present applications of our new GTL process to enable an economic exploitation of gas reserves in South East Asia and Australia, by taking into account the operation results of the Yufutsu GTL pilot plant of 7BPSD located at Tomakomai city in Hokkaido of Japan, and the study results of process simulation and the economics. We present an attractive combination scheme for our new GTL process with LNG plant by utilizing CO2 exhausted from LNG plant. It reduces initial project's investment compared with a stand-alone GTL plant located in South East Asia and Australia, where infrastructure of an LNG plant can be for common use with our GTL plant.
Optimisation CO2 Removal Design for Block B-17 in the MTJDA
Authors: Chenboonthai Nuntasak 
Published: December 2007

Abstract
Nine gas fields have been discoved in Block B-17 in the Malaysia-Thailand Joint Devepment Area (MTJDA). Most of them have high CO2 content which makes the gas unmarketable. To achieve the commerciality, CO2 content needs to be reduce to the level that the existing market is able to accept the Block B-17 gas. Under the GSA-HOA which had been signed in 1999 between Buyers and Sellers, it had specified the CO2 content not more than 23 mole%. Therefore, the Sellers need to design the gas processing facilities to meet the requirement of Buyers. Generally, the value of sales gas is based on its heating value, not volume. The high CO2 content means the less heating value resulting the less revenue. Therefore, the Sellers must reduce the CO2 content in sales gas as low as possible. Paradoxically, the more removal of CO2 content in sales gas does not indicate the best economic results, due to the high investment cost. To optimise the project economic, the percentage of CO2 content has to define under the specification of GSA-HOA and economical consideration of the project. Several factors, for instance, gas compositions, reserves, well deliverability, need to be taken into the account of the processing design.
In order to achieve the maximum benefit, the CO2 removal optimisation has to be properly designed. This paper will present a model which describes the relationship between values of sales gas and the CO2 removal cost resulting in i) good economical regime with available raw gas quality in the Joint Development Area (JDA), and ii) raw gas mixture for optimum sales gas heating value which relates to economic design of the CO2 removal.
Pressure Activated Deployment of Openhole Memory Logging Tools Into Directional Wells and Past Bad Hole Conditions
Authors: Spencer M. C. , Ash S. C. , Elkington P. A. S. 
Published: December 2007

Abstract
Openhole memory logging was introduced in 2000, initially as a more efficient alternative to pipe conveyed quad-combo wireline logs in high angle and horizontal wells and wells with bad hole conditions. By 2001 a range of deployment techniques had been developed that provide high-quality, low-cost, post-drilling formation evaluation logs to supplement basic real-time data (such as navigation and gamma ray). Among the new techniques is a shuttle system that conveys memory tools rapidly to TD inside drillpipe, ideally as part of a wiper or check trip. In one manifestation a dart pumped from surface releases the logging string after the assembly reaches TD, then moves the string from the drillpipe into open hole. This variant has been successful in over 350 wells. In a new development the dart has been eliminated, replaced by an electro-mechanical pressure activated release mechanism that eliminates the dart pumping time, has better power management for longer operations, and is capable of simple two-way communications – a key element in a repeat formation pressure tester being developed for memory operations. A slim variant operates in wells down to 4 1/4-inches bit size.
Blending Formal and Informal Learning Offers New Competence Development Opportunities
Authors: Collis B. A. , Margaryan A. , Kennedy M. W. 
Published: December 2007

Abstract
A shift from content-based to activity-based learning is taking place at the Shell Open University (SOU), with already more than 100 course events redesigned from a classroom only model to this new model. It emphasizes work-based activities, supervisor involvement, and sharing of knowledge and experiences via a blend of formal and informal learning. Results to date and lessons learned are presented.
Independent Environmental Data Verification: Views and Experience
Authors: Tan G. T. , Al Riyami M. 
Published: December 2007

Abstract
This paper described the independent environmental data verification process undertaken by Petroleum Development Oman (PDO). It was an opportunity to demonstrate external assurance process for environmental data integrity and hence improve PDO's reputation. It ensured a disciplined and structured process to data gathering and management as well as providing valuable learning to staff during the verification process.
The financial methodology used for the verification need some modifications to make it more suitable for environmental data verification. Verifiers who have knowledge of the technical nature of environmental data gathering and management are critical to the success of the verification.
Deep Water Gas Fields Intervention Using WROV
Authors: Labib AbdelRahman 
Published: December 2007

Abstract
In the last few years, there has been a significant increase in gas production to meet the global energy demand. To date, most of the recoverable gas potentials are situated in offshore concessions, and mostly in deep water. Therefore, the need to consider the environmental and technical challenges to establish and maintain any offshore gas production facility are important to the success of the field development and operation.
The use of remote technology has been used in the subsea sector of the oil and gas industry for many years; however, the scale at which it has been used in the past against the needs for the future is becoming a major consideration to the development and operation to any subsea gas production fields. Remotely Operated Vehicles (ROV) is one of the most advantageous remote tools to any deepwater operation. Introduced to the offshore industry over 25 years ago the ROV has developed from a simple observation vehicle into a sophisticated underwater work platform (Work Class ROV) reaching depths of 4000mtrs and beyond. The numbers of tasks that WROV can perform cover are many and varied and are referred to as "ROV intervention operations". Typical examples of intervention tasks are subsea production system; valve actuation, component replacement, control umbilical connection. With the majority of these tasks undertaken by the ROV, and some intervention tool specifically designed for the task.
Intervention accounts for 2 – 3 % of the total cost of offshore oil production, it frequently paces other operations on the critical path during oil field construction and operation because the operation of very costly equipment (such as supply vessels, drill rigs, and derrick barges) depends on the success of ROV operations. Making these operations more efficient and reliable will produce a large cost saving ripple effect throughout the aspects of the offshore operation.
Integrated Approach for Seismic Fracture Characterisation for Improved Reservoir Performance
Authors: Angerer Erika , Lanfranchi Pierre , Pharez Stephen , Rogers Stephen 
Published: December 2007

Abstract
The flow properties of fractured reservoirs are highly dependent on the prevailing fracture characteristics. A detailed knowledge of these subsurface patterns is therefore crucial for optimising reservoir production and performance. Fracture information is available at a wide range of scales. At one end, there are structural interpretations and basin models that describe faulting on a kilometer scale and at the other end, downhole measurements (borehole image logs) and core samples which provide fracture characterisation on a centimeter scale. Fractures of all lengths are created by regional tectonic stresses and therefore have comparable characteristics, such as orientation and density, regardless of scale.
The seismic method records reflections that exhibit azimuthal variations in amplitudes and traveltimes in the presence of fractures. Thus the gap between faults and micro features is bridged by sub-seismic fracture characterisation from azimuthal anisotropy (Rüger, 1998, Bakulin, et. al., 2000). An integrated workflow is presented that reconciles all available geological, geophysical and engineering information to build unified and consistent fractured reservoir models.
Residual Oil Saturation Analysis of The Burgan Formation in the Greater Burgan Field, Kuwait
Authors: Al-Sabea Salem , Bean Clarke , Crowe John 
Published: December 2007

ABSTRACT
Residual Oil Saturation (Sorw) is a critical reservoir model parameter for evaluating reserves in the Greater Burgan Field. Past Sorw studies in Greater Burgan Field either looked only at core test data, or only looked at cased-hole log data. None of the past studies considered areal position, different rocktypes, or changes in remaining oil saturation with varying amounts of water sweep.
This study includes analysis of Sorw from open-hole water saturation, Time-Lapse PNC data and Special Core Analysis water flood experiments.
The majority of the log data in Greater Burgan Field water –swept zones are concentrated in the 3rd sand middle, 3rd sand lower and 4th sand formations. The comparisons of the results from all three methods used in the study to measure remaining oil saturation (ROS) are limited to these reservoirs.
Results from these methods were remarkably consistent.
All reservoir sand with extensive PNC log data showed that zones encroached by water for 22+ years tend to be at or near residual oil conditions. Measurements in the zones with water encroachment for less than 22 years have about a 50% chance of being incompletely swept. Analysis of the 22+ year data allowed reasonable ranges of Sow were estimated from this data.
Investigations of ROS spatial variations in the Magwa, Ahmadi and Burgan sub-fields were made. 3rd sand middle was the only reservoir with both adequate PNC and open-hole coverage in ROS from these three areas in Greater Burgan Field.
ROS by rocktype was reviewed in three categories of reservoir rock (excellent, medium and poor quality reservoir) as currently defined by log analysis in Greater Burgan Field. The vast majority of log data occurs in rocktype 1, the highest quality reservoir rock. Only 3rd sand lower formation contained sufficient data in all three reservoir quality rocktype to make valid comparison. Both core flood Tests and PNC Time-Lapse methods also showed no difference in ROS based rocktype.
Comparison of Permeability Predictors from NMR, Formation Image and other Logs in a Carbonate Reservoir
Authors: Hassall J. K. , Ferraris P. , Al-Raisi M. , Hurley N. F. , Boyd A. , Allen D. F. 
Published: December 2007

Abstract
An extensive petrophysical analysis has been carried out on a study well in a giant carbonate field in the Lower Cretaceous of Abu Dhabi. The well was cored, and a comprehensive log suite recorded including: Nuclear Magnetic Resonance (NMR), Borehole Imaging, Shear Sonic and Mineral Spectroscopy in addition to the more normal logs.
A high-resolution permeability profile was measured on the core. Plugs taken every foot were supplemented by minipermeameter measurements every inch. While this profile captures high frequency variability it is limited in its applicability to predicting reservoir behavior. Analysis of large scale flow unit permeability is better assessed with dynamic data.
A number of advanced log based permeability estimators were developed in an attempt to match the core permeability profile. The estimators are based on NMR, image analysis and Stoneley measurements among others. This paper presents a comparison of these predictors to the core and makes recommendations as to the preferred permeability prediction methods for this field.
For this well the Stoneley permeability correctly predicted a trend decrease of permeability with depth but failed to honor the full extent of the trend. As expected, given its vertical resolution, it also failed to respond adequately in the more heterogeneous intervals.
A method based on a mean NMR T2 measurement gave a good general match to the data, but again lacked vertical resolution. An electrical image based method brings an important improvement in sensitivity to the small-scale variations in permeability, but in some places failed to follow the lower frequency trends.
A composite method using the NMR to supply the overall trend, and the image to provide the higher resolution, gave the best match to the core permeability profile available from the tool suite, which was run. The method is a modification of the well-established SDR permeability equation. A new term is introduced to account for the contribution of connected vugs, which are responsible for the high permeability intervals in this well.
The logs used in the methods described here do not make direct measurements of permeability. Instead permeability is inferred indirectly from measurements sensitive to parameters such as texture and pore size. It is doubtful that a single methodology based on such measurements can provide a "universal" permeability estimator fitting all cases. The methods presented here should be applied with care and will benefit greatly from calibration to spot permeability data.
The method has particular application in high cost environments where a good permeability is required along the wellbore but the cost and rig time required for continuous whole coring cannot be justified.
Underbalanced Drilling; Remedy for Formation Damage, Lost Circulation, & Other Related Conventional Drilling Problems
Authors: Qutob Hani 
Published: December 2007

Abstract
Almost every drilling operation is a potential source of damage to well productivity, lost circulation, differential sticking and other related conventional Drilling problems.
This paper re-visits the key damage mechanisims and provides a broad overview on how they occur during various oilfield operations, and their effect on well productivity. Also, lost circulation or fluid invasion potential in high permeability zones, large open fractures, heterogeneous carbonates with massive interconnected vugular porosity, or pressure depleted zones would be a major issue of concern during conventional drilling condition. The worst-case scenario would be a combination of one of these high permeability features with significant pressure depletion.
In order to overcome the above problems while drilling, the industry developed a method to drill with a bottom hole pressure below the pore pressure, called Underbalanced Drilling – UBD
As the majority of hydrocarbons being exploited today are found in existing pressure depleted or complex and lower quality Reservoirs with lots of the conventional drilling problems, this is where Underbalanced Drilling Technology can add value and in some cases reduce development cost. Soon, Underbalanced Drilling will become the standard field development technique, both Onshore and offshore, where the Geology and Reservoir are suitable.
The paper reviews several case histories and real results highlighting the advantages of Underbalanced Drilling Technology in reducing Formation Damage, Lost Circulations and improving well productivity.
Evaluation of IOR Potential within Kuwait
Authors: Al-Bahar Mohammad A. , Merrill Robert , Peake William , Jumaa Mohammed , Oskui Reza 
Published: December 2007

Abstract
Kuwait's production to date is characterized by large, massive reservoirs undergoing natural depletion with the help of strong natural aquifer drives. In a few fields, natural aquifer support is supplemented by pattern or peripheral waterflood. However, there has been no systematic attempt to define the Improved Oil Recovery (IOR) potential within the country. This study is a first attempt to assess this potential. The study considered 10 IOR displacement processes, suitable for long-term implementation within Kuwait. These processes included waterflood (including chemical floods), gas injection processes, and thermal methods. The study did not consider techniques based purely on well stimulation or infill drilling (e.g. cyclic steam injection, or horizontal well development); the potential for these techniques is already well understood and considerable data already exists for planning around these options. The study focused on screening reservoirs and identifying IOR processes for further study.
The screening was in two parts. The first part was an evaluation of process suitability for all reservoirs. The second part was a ranking of IOR opportunities by reservoir. In total, over 800 process/reservoir combinations were evaluated. The evaluation process made use of various industry criteria; however, these were modified to better reflect conditions within Kuwait. After screening for suitability, the reservoirs were ranked in importance for future study. This ranking included: incremental oil recovery, crude quality cost per barrel and urgency (timing). This ranking will be used to direct resources at particular projects for further study and, if positive, future implementation. Key technical contributions of this work include: data evaluation techniques, consistent ranking of reservoirs with varying degrees of risk, development of scoping economic models for preliminary project assessment.
Transient Behavior of Annular Pressure Build-up in HP/HT Wells
Authors: Oudeman P. , Kerem M. 
Published: December 2007

Abstract
Pressure build-up due to fluid thermal expansion in sealed annuli of HP/HT wells can have serious consequences such as casing failure or tubing collapse. To determine whether mitigation was required for a HP/HT development, annular pressures in an appraisal well were studied with a dedicated field test, which consisted of running a pressure/temperature memory gauge in a casing/casing annulus of a well and testing the well several times during a 3-month period, after which the gauge was retrieved and the data were read out.
First of all, comparison of the magnitude of the observed annular pressures with the burst and collapse ratings of the casings, shows that annular pressure build-up is a serious consideration in casing design. Such design is to be based on theoretical models for annular pressure build-up. The data acquired with the test serve to validate these models.
The data demonstrated that in the lower temperature range (20 to 40 °C), on average, pressure development in the annulus agreed reasonably well with theoretical model predictions, based on thermal expansion of the annular fluids and casings, and ballooning and compression of the casing strings. The influence of these factors could be established by analyzing the transient pressure response of the annulus. At higher temperatures the theoretical models overestimate pressure build-up. This is probably to be attributed to the properties of the completion fluids differing from the properties of the base fluid, water. Estimates on the basis of pure water properties can be considered a worst-case estimate for pressure build-up.
Leak-off of the annular fluids, which was seen to dominate pressure development during a previous test in a well with a cement shortfall between casings, did not play a significant role in this fully cemented and sealed annulus.
Multiphase flow meters (MFPM) – Field trials and their applications in fields
Authors: Bekkousha Miloud , Khoory Ahmed , Metwalli Magdi , Jawahiri Hamza Al , Sakaria Dipak , Rajabi Shehta Al 
Published: December 2007

Abstract
Abu Dhabi Company for Oil Operations (ADCO) UAE have been field testing and assessing the multiphase flow meter (MPFM) technologies as an alternative well testing tool for the past decade.
Currently, there are not any governing industry standards existing for the MPFM technology. Commercially available industrial MPFMs each apply their own unique technology and principle, which are sensitive to the fluid properties and flow regimes, which ultimately dictate the final MPFM reading. Every reservoir has its own characteristics and behavior, which changes with time and ultimately affects the MPFM measurements. Hence the selection of the MPFM suitable for its exclusive application is critical.
In order to implement and apply with confidence the MPFM technology and achieve optimal results, field trials are necessary for both the operator and the engineer. The field trials will further develop the knowledge (its limitation, potential and its behavior) of each of the MPFM's technologies available in the market.
This paper describes ADCO's experience and the methodology that was applied for the selection of MPFM and there upon its accuracy, reliability and its performance to develop confidence of the application and its usage.