bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidences for New Attractive Gas Exploration Targets in Abu Dhabi Upper Permian Section
Authors: Taher Ahmed K. , Al Suwaidi Ahmad S. , Al Habshi AbdulRahman 
Published: March 2009

Abstract
The great Paleozoic system of the Arabian Gulf forms one of the most prolific hydrocarbon producing systems in the world. The Primary elements of this system like source, reservoir, seal and traps are extended throughout the eastern Arabian Peninsula and have exceptional scale and quality. Modeling of the structural growth history, in conjunction with the hydrocarbon generation and migration in the area, has shown that early growth and charge were essential conditions for the formation of economic hydrocarbon accumulations.
The recent basin modeling of the Silurian Hot Shale source rock showed that the gas generation deadline was during the Late Tertiary (20 Ma), while the onshore fields main phase of structural growth was during the Late Cretaceous Semail Ophiolite Obduction. Also, the potentiality of gas accumulations was further enhanced by the Late Tertiary tilting. The tilting resulted in spilling and migration of gas from the palaeo-structures in the east towards the giant structures in central Abu Dhabi.
The Upper Permian Fluid Inclusion Volatile (FIV) analysis proved the presence of strong gas migration through much of the Abu Dhabi area and based on that, no source risk is present as previously suggested for the Upper Permian and Lower Permian reservoirs. The fluid inclusion analysis generally observed more mature source that resulted in drier gas in the onshore area and wetter gas to the northwest in the offshore fields.
The drilling results evaluation indicated the presence of significant hydrocarbon shows while drilling the Upper Permian porous carbonate intervals. Also, the log data indicated the presence of high hydrocarbon saturation that ranges between 50 and 90% in most of the onshore Upper Permian drilled structures. However, the longer diagenesis process and the deeper depth of the burial of onshore structures have greatly affected the reservoir properties and possibly resulted in high non-hydrocarbon content.
The causes of failure of some Upper Permian reservoirs in Abu Dhabi are most probably related to the limited data and experience at that time; which resulted in drilling and testing difficulties that possibly caused formation damage of the Upper Permian reservoirs. Also, the seal preaching and the limited charge could not be ruled out as negative factors for lack of gas accumulations in the Upper Permian section. However, the current technology improvement in basin modeling, deep drilling and tight reservoirs testing may turn the Upper Permian negatively tested reservoirs in Abu Dhabi fields to an attractive exploration targets.
A New Approach For Improving Permeability Estimation by Integrating Sequential Gaussian Simulation (SGS) With Co-Active Neuro Fuzzy Inference System (CANFIS) Network
Authors: Rafiei Yousef , Mirkalaei S. M. Mousavi , Masoudi Rahim , Ataei A. , Khordoo Mahmood 
Published: March 2009

Abstract
This paper shows that geostatistical modeling integrated with Artificial Neural Network (ANN) can be effectively used to estimate permeability when limited amount of core and log data is available.
The goal of this study is to create a good calibrated data set, and then designing a proper network for permeability estimation in one of Iranian oil reservoir. In this reservoir coring have been done only in one well. Therefore due to widely scattered and limited number of data, conventional methods of permeability estimation such as empirical equations and multi linear regressions gave poor prediction.
New approach was developed in which, geostatistical modeling is performed to create comprehensive data set. After that this data set will be used to design and train neural network for prediction of permeability.
In this work, at first the reservoir has been classified in to two different flow units to overcome the extreme heterogeneity of the reservoir. Then Sequential Gaussian Simulation (SGS) was performed to obtain very fine permeability distribution versus depth and log data in cored intervals of each flow unit of the reservoir. After that uncertainty analysis has been done to create data set by selecting the best points with highest probability and lowest value of standard deviation. These data were input to design and train the Co-Active Neuro Fuzzy Inference System (CANFIS) Network. This network is based on Fuzzy Logic algorithm that its parameters obtained from learning rules of neural network. Then core data are used to test the network. The results show the acceptable estimation of permeability. Finally network can affectively be used to estimate permeability in uncored but logged wells.
Applying Precision Drill Pipe Rotation and Oscillation to Slide Drilling Problems
Authors: Gillan Colin , Boone Scott , Kostiuk Greg , Schlembach Catherine , Pinto Jason , LeBlanc Marc 
Published: March 2009

Abstract
The paper describes how a computer controlled top drive can address slide drilling problems and reduce rigfloor personnel exposure using precision pipe rotation and oscillation. It presents the advantages of such a system in solving the problem of setting a downhole toolface orientation and compares itself with the current practice. The paper explains further improvements in drilling efficiency and toolface control in the slide drilling mode in four case studies using field data and log analysis. A case history discusses how an operator was able to use the system to drill complex 3D wells using mud motors where previously only rotary steerable systems were capable. A section presents how the system reduces personnel exposure on the drill floor. The system is compared to other techniques of improving drilling performance in highly deviated directional wells.
In the current drilling environment, operators are constantly seeking to reduce costs, improve drilling efficiency and ensure the safety of all personnel. This application adds efficiency to the drilling process in reducing rig flat time caused while establishing downhole toolface settings for directional control. It also adds efficiency by delivering more effective weight on bit in highly deviated directional wellbores and in providing a digital method of controlling downhole toolface while drilling. The improved toolface setting procedure via a touch-screen computer removes the need for directional personnel to chalk drill pipe and spend time on the rotary table, working instead with the driller from the doghouse or control cabin to achieve the required pipe rotation and toolface. The directional steering control system can also be used to maintain a desired toolface setting across drill pipe connections, dramatically reducing the flat time per connection. In these key elements, this system provides significant time saving advantages over the current practices.
Innovative Solution to Isolate Cross Communicating Reservoirs in Short Radius Wells
Authors: Al-Mumen Adib A. , Balghoneim Hatem F. , Al-Amri Khalifa M. , Al-Baggal Zaki A. 
Published: March 2009

Abstract
Cross communication between reservoirs is a common phenomenon in oil fields worldwide. The cross communication not only hampers production but also alters reservoir properties which affects the future recovery targets. Isolation of these cross communicating reservoirs in short radius application has always posed a serious challenge to drilling engineers worldwide. This paper will describe two challenging remedial workovers where the window was successfully isolated and squeezed after isolating the short radius curve section. The first well is a bare foot completion while the second well was more challenging as it is completed with production equalizer liner. The paper will also highlight the evaluation process and risk assessment of the other options with economic analysis. Moreover it will shed some light on the limitations of the available retrievable isolation plugs in short radius applications. At the end the paper will emphasize the time and cost saved in achieving the objectives and will show production results of the two wells after the remedial work.
Improved Method for Compositional Modeling Using a Fine Scale Geological Description Within Gas Injection Pattern in Carbonate Reservoir
Authors: Obeida Tawfiq , Gibson Adrian , Al-Hashemi Hussain , Baruah Bikram 
Published: March 2009

Abstract
The objective of this paper is to address the challenges that are frequently encountered in simulation studies when using local grid refine (LGR) within upscaled models. The difficulties mainly arise due to the unreliability of populating the fine grids with reservoir properties and attributes.
Dynamic modeling of a pilot is an important task to predict fluid flow and reservoir behavior which is a major step of pilot design. Dynamic models usually have many limitations when it comes to geological description due to the upscaling of fine-grid static model. Using local grid refinement (LGR) alone for the pilot area within a coarse dynamic model also would not enhance reservoir description of the pilot area without a realistic reservoir description. This work was aimed to provide an improved method for the proper simulation of pilot project in order to optimize the design of the pilot injector, borehole location and length. Furthermore, the model would be used to plan an efficient reservoir monitoring program including an optimized well data gathering with sponge coring for defining the remaining oil saturation.
To overcome these limitations, the proposed method introduces a special fine scale LGR covering the pilot area within the upscaled dynamic model. Whereas the upscaled model has 36 layers, the LGR contains exactly the same fine-scale layering scheme and reservoir properties as the static model with 160 layers. Thus, it eliminates the upscaling process within the LGR. This process will ensure a better quality history match, for example the TDTs and RSTs derived saturations when compared against the fine layer LGR from the dynamic model.
The dynamic model in this study is a large sector model (Nx 167, Ny 98 and Nz 36) with a detailed LGR (Nx 130, Ny 145 and Nz 160). The fluid properties were calculated from a 10-components equation of state (EOS). After the addition of the LGR, the model history match was updated. Several prediction cases were then studied to optimize well location (injector and observation wells) in order to convert the existing inverted five-spot gas pattern into water injection line-drive. Several saturation maps and profiles were generated to predict the breakthrough time for each observer and utilized to design the future pilot monitoring program. The new data will be utilized for future updates of the history match and performance of pilot under the optimum scheme of sweep and thus well spacing.
Advanced Technologies for Critical Drilling Applications
Authors: Jellison Michael J. , Spoerker Hermann F. 
Published: March 2009

Abstract
This paper provides a review of recent technology advancements and addresses practical considerations associated with drill pipe and drill stem components for extreme drilling applications. Ultra-high torque double-shoulder rotary connections are often employed in these applications potentially complicating proper design and material selection for cross-overs, top-drive subs, pup joints and other accessories These new connections often employ materials with higher strength requirements than the standard API connections they replace. The paper outlines recommendations for material strength and design parameters for various drill stem accessories. High-performance connectors' impact on BHA design is also addressed. Weight tapered drill string designs with double-shoulder connections can result in mismatched connection bores or ID's. Guidelines to accommodate this mismatch along with supporting finite element modeling results are presented.
Proper hardband selection, application and maintenance are essential to successfully and safely drill world-class UD, ER and deep-water projects. Hardband system trends for critical applications are highlighted, and recent hardband casing wear and tool joint protection test results obtained using an advanced hardband wear machine are discussed.
Due to the dramatic increase in oil prices the industry has seen a re-emergence of deep and ultra-deep drilling projects that encounter H2S gas. The paper provides initial results from a study of the effect on S-grade drill pipe samples to various H2S exposure concentrations, representing typical conditions when circulating a gas kick to surface.
The surge in critical drilling has led to an increasing trend of drill stem friction heating failures. The paper includes characteristic features of these failures along with case histories and prevention methods. High-speed telemetry (wired) drill pipe has been successfully deployed on critical drilling applications in various parts of the world. The paper provides an update on this exciting technology and reviews recent case histories.
Permeability Estimation Using Log Data, Abu Dhabi Offshore Field, UAE
Authors: Bazara Magdi , Salman Salman M. 
Published: March 2009

Abstract
One of the major elements used to evaluate an oilfield reservoir is the rock Permeability. It's also used in many other aspects such as reservoir simulation, rock type definition, etc. There are many methods utilized to measure / predict formation permeability (Well Test, MDT, Core analysis…).
Rock Permeability indicator significantly increases with porosity for the intergranular-type formation (not applicable for noninterganular rock, such as formation containing solution channels, vugs or fracture); however it is also quite dependent on the surface area presented by the grains. On the other hand, irreducible water saturation reflects the surface area. Therefore a function of porosity & irreducible water saturation can help in prediction of the absolute permeability. In our case study, the actual Sw (initial) were used in this function, hence the Permeability obtained actually represent the effective rather than absolute value.
Through the petrophysical evaluation of an offshore oilfield in Abu Dhabi, it was noticed that by applying a function of Water Saturation, Porosity & other coefficients, there were a good match between the Permeability estimated using open-hole log data & Permeability measured from the core sample in the laboratory. A step further of this quality check to this function is taken by comparing these results to the wells test & having an overall comparison over the full field data in-hand.
This paper focuses on establishing a correlation between open-hole log data interpretation & permeability measurement from the core sample that resulted in generating an empirical equation capable of predicting the permeability from the open-hole log data.
An Update and Perspective on Field-Scale Chemical Floods in Daqing Oilfield, China
Authors: Pu Hui , Xu Qinglong 
Published: March 2009

Abstract
Chemical enhance oil recovery(EOR) like polymer flooding and Alkaline-Surfactant-Polymer(ASP) flooding have been applied throughout the world for more than 20 years. However, few large-scale successes with these processes have been reported, except in China. To date, polymer flooding has been successfully applied industrial scale in Daqing since 1996. Polymer flooding alone contributed more than 10 million tons of oil in 2006, which occupied 25% yearly rate of Daqing. Incremental oil recoveries of up to 14% of OOIP have been obtained in the field. Much experience and lessons have been learnt on large scale polymer flooding including: major factors that influence the recovery and methods to increase the recovery; measures to obtain a uniform polymer injection profile; and how to lower the costs of polymer flooding.
Also Daqing performed researches on other chemical floods application, such as surfactant flood, micellar-polymer flooding(MP), alkaline flooding, alkaline-surfactant-polymer flooding(ASP), alkaline polymer flooding(AP), ASP-foam, especially ASP. Those chemical floods were field tested or are testing to increase oil recovery, to study the feasibility, to provide technical and practical experience for expanding, and to find suitable post-polymer flooding enhanced oil recovery EOR technology. Through tests, the injectivity and productivity of ASP systems, the best technique of artificial lift and stimulation measures for low efficiency wells, chromatographic separation analysis in condition of different well spacing, and economic analysis of chemical EOR were all studied. Pilot test results showed that over 20% OOIP recovery can be obtained over that of waterflooding, and is both technically and economically feasible.
Overall, experiences and lessons learned in field applications of chemical floods in Daqing are extremely valuable not only for expanding chemical EOR to other areas of Daqing, also for other countries.
Mechanical Earth Model (MEM): An Effective Tool for Borehole Stability Analysis and Managed Pressure Drilling (Case Study)
Authors: Afsari M. , Ghafoori M. R. , Roostaeian M. , Haghshenas A. , Ataei A. , Masoudi R. 
Published: March 2009

Abstract
As a borehole is drilled, hydraulic pressure of the drilling mud must replace the support lost by removal of the original column of rock. But mud pressure being uniform in all directions cannot exactly balance the earth stress. Consequently, rock surrounding the borehole is distorted or strained, and may fail if the redistributed stresses exceed rock strength. The bottom line for the drilling engineer striving to maintain stable hole is choosing the right mud weight.
The aim of this study is to build a Mechanical Earth Model using available data for one of the Iranian oil field to evaluate wellbore stability and to choose optimum mud weight.
For making MEM different sources of data including, drilling data, logging data, DST, MDT, LOT, FIT, etc were used. After making MEM with available data, suggestion for selection the right mud weight for each interval to prevent the common instability problems (lost circulation, borehole breakout) was made.
MEM for this field can now be used to predict not only the safe mud weight window and possible drilling hazards, but can also be used for studies like sand production and perforation stability and so on.
Numerical modeling has been carried out using MEM data for comparing analytical and numerical wellbore stability analysis to select optimum mud weight, to investigate the feasibility of managed pressure drilling for problematic formations, and to determine the most effective azimuth for drilling horizontal wells into the reservoir section.
Understanding of Oilfield Souring and Effective Monitoring: Two Cases Study
Authors: Nengkoda Ardian , Mandhari Musallam , Hajri Mohammed , Barhi Hilal , Qasmi Liali , Hofland Ron 
Published: March 2009

Abstract
In the X oilfield Sultanate of Oman, water has been injected since June 2001 for EOR purposes. The water supply sources, was used through 4 dedicated injection wells, at a maximum total rate of 4000 m3/d in early 2003. By end of April 2003 the injection water source was switched to produce water, and separated at in line separator. The production wells suddenly turned to produced high H2S, while the well injectivity decline around 50% and levels have caused concern for on going Field Development scenarios. Meanwhile, in opposite, in Y oilfield, when discovered, the field was found to be sour, hence production facilities were designed for sour service. Occasional monitoring confirmed high H2S levels to prevail, but also showed an alarming increase with time, casting doubts on future integrity assurance. As the materials used in the X and down stream receiving facilities are not to be NACE 175 souring compliant and consider H2S released are hazard for safety. Starting December 2005, production chemistry and reservoir study have initiated an integrated H2S Monitoring and implemented a Mitigation Program by improving H2S onsite measurement and method revision, adopted instrument calibration accuracy, established frequent surveillance teams, investigated the caused of souring by Sulphur Isotope methodology for both X and Y field, and monitor the produce solid. Overall its improved business performance, HSE awareness, saving the plant upgrade cost, and finally now days in November 2008, the H2S level from X Field become traces and the area is safe for full field development.
Sulfur and Asphaltene Deposition During CO2 Flooding of Carbonate Reservoirs
Authors: Zekri Abdulrazag Y. , Shedid Shedid A. , Almehaideb Reyadh A. 
Published: March 2009

Abstract
Simultaneous sulfur and asphaltene deposition in porous media as a result of CO2 injection may significantly reduce the CO2 flooding injectivity and create plugging problem and might affect the recovery efficiency of the process. Accurate assessment of sulfur and asphaltene deposition during CO2 is critical information for the design of viable CO2 flooding process.
The main objective of this work is to investigate the simultaneous deposition of sulfur and asphaltene in the porous media during CO2 flooding. To achieve this objective, the influences of water saturation, type of flooding process i.e. slug and continuous, CO2 injection rate, and permeability of the system on the oil recovery and the losses of sulfur and asphaltene in the reservoir rocks were investigated. Nine experiments were carried-out using one of UAE oil reservoirs crude oil. The results indicated that both sulfur and asphaltene were precipitated in the system and in general higher sulfur loses to the pores media as compared to asphaltene was observed.
The Use of Tracers for Reservoir Characterization
Authors: Anisimov L. A. , Kilyakov V. N. , Vorontsova I. V. 
Published: March 2009

Abstract
The use of tracers in the reservoir studies shows that this is the best method to evaluate the downhole region of the well and interwell space. Traditionally, the reservoir studies have combined the integration of the geological, geophysical, and well tests as well as geochemical data and production history to construct geologically realistic models. Tracer methods give new opportunities to evaluate the fluid-flow properties and continuation or compartmentalization of reservoirs. Radioactive and chemical tracers have been used in Volgograd Region to construct hydrodynamic models of clastic and carbonate reservoirs.
The method of radon indication has been used for downhole region evaluation. After radon injection, the permeability along the vertical section in a well can be calculated according to the level of radioactivity on a log. The convective nature of tracer-tests provide additional information about the reservoir. The following parameters are used for interwell space evaluation: tracer velocity (time of flight from injection to production wells) in a reservoir; tracer concentration as the consequences of tracer dissolution in formation fluid flow; frequency of the tracer presence in samples – a number of tracer pathways from injection to production wells. The use of tracer survey method can evaluate the vertical fluid flow barriers, reservoir continuity in every block, fluid-flow properties, and understanding of the reservoir architecture in the interwell space. The main result of tracer method is the ability to detect the ultra high permeability zones that cannot be found by other methods of reservoir analysis.