bluuebunny/crossref_metadata_2025_split huggingface dataset:
Management of Asphaltenes Deposition in a Giant Carbonate Onshore Oil Field, Abu Dhabi, U.A.E.
Authors: Misra Sanjay , Abdulla Dalia , Bazuhair Mohammed , Aboukshem Ali , Stenger Bruno , Katheeri Abdulla Al 
Published: September 2011

Abstract
Recently observed production behavior in a maturing carbonate oil reservoir indicated that many production strings were getting plugged with solid scales, requiring tubing clean-out jobs. This is the main reservoir of a supergiant onshore carbonate oil field operated by ADCO since 1973. Some cases proved to be no more than calcium carbonate scaling following water breakthrough and the tubing blockage was successfully treated with acid washing. A number of plugged strings revealed that a non-mineral hard scale was the cause of the blockage. Upon analysis, such scales proved to have an organic composition rich in asphaltenes. While solvent washing was successful in removing the blockage, rapid reoccurrence was observed in many cases. The subsurface asset team embarked on a detailed reservoir monitoring and fluid compatibility study to establish causative factors. One of the aims of the study was to check a possible link between the asphaltenes deposition with a naturally occurring tarmat and a rich-gas injection pilot, both located in the severely affected part of the reservoir. This work revealed that although the severity of the problem is higher in the tarmat area, asphaltenes mobilization from the tarmat layer was not considered a realistic mechanism. Although PVT studies revealed that rich gas dissolution in the crude at reservoir conditions triggered asphaltenes instability and precipitation but occurrence of asphaltenes deposition in the field seemed unrelated to the rich-gas injection as the injected gas was moving in a different reservoir subzone. Most of the plugged strings were unlikely to have had gas breakthrough at the time of problem detection and no clear spatial relationship could be evidenced. A preferred explanation may be that asphaltenes precipitation is related to differences in crude oil composition within the studied reservoir. The reservoir might have seen successive oil influxes from two source rocks with wide distribution of mixing ratios. Asphaltenes originating from one of the source rocks might cause greater fluid instability even at the observed low concentrations. Production rate sensitivities indicated that asphaltenes blockage was retarded at higher production rates. Many asphaltenes dispersant/inhibitor chemicals were evaluated for effective tubing clean-out and preventing asphaltenes deposition. Some chemicals proved to be more effective in mitigation and prevention of asphaltenes deposition.
Hammer Drilling Technology - The Proved Solution to Drill Hard Rock Formations in the Middle East
Authors: Vieira Paco , Lagrandeur Craig , Sheets Kelly 
Published: September 2011

Abstract
The drilling of "hard rock" formations represents a considerable percentage in the overall cost of a well where these types of formation are present. Low rate of penetration, number of bits required and tripping time are the main factor contributing in the increase of the overall cost. Nowadays this is classified as Invisible Non Productive Time (INPT). Drilling through hard rock could be in some cases the limiting factor to economically develop significant hydrocarbon reserves in some areas. The improvement in the penetration rates in hard rock drilling is an opportunity to reduce overall well costs and the INPT. The Middle East area has in some of their field stratigraphic structure, the presence hard rock formation where the hammer drilling technology has proved to be the most efficient way to drill theses sections. Even though it is not a new technology because it was introduced in the early sixties, it has gained good momentum worldwide and the Middle East Area. Formations with UCS values above 25.000 psi have shown that hammer drilling technology has been able to improved rate of penetration in the factor of 20 and above, thus having a considerable impact in cost. This paper describes the engineering an operational result of the implementation of Hammer drilling technology in the Middle East and the future of the expanding trend if it is used in the area.
New Technique to Sidetrack Across Hard Formation in North Oman
Authors: Ahmed Al Salmi , Younes Al Haji , Saif Al-Hamhami , Isehaq Sabhi , Abduallah Al Fadhli 
Published: September 2011

Abstract
In a north Oman field, it is common practice to cement vertical pilot holes up to the kickoff point. A cement plug is then used to initiate the sidetrack through extremely hard formations. Previously, it has taken several attempts to sidetrack these holes and, in some cases, a mechanical whipstock had to be used.
There are challenges when trying to initiate the sidetrack because the formation hardness far exceeds that of the kickoff cement plug. As a result, the sidetracking assembly is repeatedly directed back into the relatively softer cement plug (i.e., vertically). Gravity also plays a role to some extent in bringing the sidetracking assembly back into the vertical hole, increasing the challenge.
This paper documents successful implementation of modifications to the slurry design and cementing procedure, as well as the successful use of a side-tracking method/technique in North Oman.
The compressive strength of cement has been increased from 5,000 to around 9,000 psi for standard, 17-lbm/gal, Class G cement.
The effect of oil-based mud (OBM) contamination has been examined and spacer designs have been improved to help ensure good mud displacement while performing cementing operations.
The sidetracking method and tools have also been improved with impressive results. This includes proper selection of the kickoff point based on the drill-speed log of the vertical pilot hole, selecting the correct combination and configuration (e.g., outside diameters of components and angle setting) for the bottomhole assembly (BHA), and using the correct application parameters and techniques while initiating the sidetrack, which is also called "time-drilling."
This paper investigates the new techniques applied in detail and clearly illustrates their development. Some case histories are also presented.
Seeing the Invisible: Predicting Fluid Paths with Innovative Curvature Attributes
Authors: Saleh Al-Dossary 
Published: September 2011

Abstract
Natural fractures and faults in the subsurface play an important role in fluid flow and accumulation. Therefore, identifying and mapping the distribution of fracture and fault systems is critical to understanding the fluid dynamics within a reservoir.
Although fractures and small-through faults are not easily identifiable using conventional 3D seismic techniques, their orientation and intensity can often be inferred using seismic attributes, such as coherence and seismic curvature.
This case study will demonstrate how seismic curvature was used to map small scale fractures in a Saudi Arabian oil field, which has been affected by premature water breakthrough. Premature water breakthrough is an increasing concern to all the geoscientists and engineers involved in developing the field. Curvature illuminates subtle fracturing that was difficult to detect with conventional seismic amplitudes. Using curvature allows geoscientists to map, for the first time, small-scale fractures believed responsible for bringing water prematurely to the top of the reservoir. The integration of image logs, zones of lost fluid circulation, production test and well test data has increased our interpretation confidence and helped optimize the placement of future horizontal wells.
Comparison of a New Multi Laterolog Tool and a Formation Resistivity Imager in the Phiops Field of Egypt
Authors: Abdel-Shafy T. , Fattah A. , Corley B. , Khokhar R. , Maurer H. 
Published: September 2011

Abstract
The Multi Laterolog is a newly developed array laterolog logging device based on the Dual Laterolog principle, consisting of four independent focused measurements of differing depths of investigation with high vertical resolution. A model-based adaptive borehole correction (ABC) technique corrects the Multi Laterolog measurements for borehole effect in very conductive muds and large boreholes by solving for tool position as an unknown. This approach guarantees that in non-invaded intervals, all four laterolog curves are properly "stacked", even in large washouts, while invaded intervals show a consistent resistivity profile. The correction algorithm is very fast and is applied in real time during data acquisition. It also provides an estimate of true formation resistivity (Rt) that can be significantly higher than the deepest laterolog measurement. This results in a more accurate estimation of hydrocarbon saturation. With the addition of a micro-resistivity device, it is also possible to estimate the length of mud filtrate invasion (Lxo).
Advantages of the new Multi Laterolog logging tool and advanced processing principles in combination with other wireline logging tools like the Formation Resistivity Imager are illustrated by an example from the Phiops field in Egypt.
Accelerating Interactive Seismic Applications Using Fast Sorting Algorithm
Authors: Al-Dossary Saleh , AlSharikh Abdulaziz , Aramco Saudi 
Published: September 2011

Abstract
Many seismic processing algorithms require trace and/or meta data ordered in a specific domain. Sorting large 3D surveys can take days even using a large supercomputer. If an efficient sort technique is not available, users may avoid trying new seismic processing algorithms that require sorted data.
We introduce a modified merge-sort, which runs 3 to 4 times faster than Intel standard C runtime library quick sort algorithm. Our new technique improves on Donald Knuth's adaptation of John Von Neumann's 1945 classic merge sort [1] in two areas: memory management and code parallelization. Memory management is improved using pre-allocated arrays. Parallelization is performed using OpenMP.
Management of the Disastrous Underground Blowout in South of Iran
Authors: AShena Rahman , Amani M. , Taei B. , Kamyab M. 
Published: September 2011

Abstract
An underground blowout is defined as an uncontrolled flow of formation fluids from a high to a low pressured zone.
Due to the 9 5/8" casing collapse of the well no. X of MARUN Field with great tectonics, in the upper part of Aghajari Formation, Lahbari at 687 m depth, the formation oil and gas penetrated to Lahbari (with a large permeability and low formation mineral cementing) and appearing at the surface as 50 seeps (underground blowout). Most seeps were only 4 kms away from Jarahi River supplying the drinking water of three towns and additionally flows to Iran' Largest Wildlife Refuge, Shadegan Refuge which is home to a large number of flora and fauna species. The gas was set ablaze by the emergency crew to secure the environment from gas spreading and explosion.
The identification of the GPS seep coordinates and slope to the river, Construction of 31 soil dams in 3 days to accumulate oil in case of flows towards the river, establishment of a 85 m wide floating bridge after the heavy rain, application of a large number of busters, day and night operation of 1800 NISOC, UBD and emergency workers to cap the well were only part of these huge operations. Comprehensive geology, drilling and production history, incident, well capping and also especially HSE operations including future amendments would be described.
Inexistent well integrity management (WIM) to monitor leakages, casing corrosion erosion, and cement quality after 34 years of production would be presented as the main reason of the blowout while. The evidence presented clearly shows the disobeyance of the contemporary drilling manager in not extending the 13 3/8" intermediate casing to 1200 m depth according to the geological well forecast. The previous 9 5/8" casing design was confirmed after designing it again.
A Successful Introduction of a New Tools Configuration and Analysis Method for Production Logging in Horizontal Wells
Authors: Torne Juan , Arevalo Francisco , Jay Phil , Eid Mahmoud , Guergeub Nacer , Frisch Gary 
Published: September 2011

Abstract
During the last two decades, the efficiency and economy of horizontal wells have significantly increased owing to the successful introduction, adoption, and application of new technologies. Proper planning and economic evaluation of proposed horizontal wells requires sufficiently accurate geological and reservoir modeling. Without such an approach, the economic success of any horizontal well should be considered a high risk.
Production logging data in both the horizontal section and the vertical sections are important elements in evaluating the performance of horizontal wells and provide dynamic data for optimization of reservoir modeling and the determination of long-term economics and ultimate recoverable reserves. However, acquiring quality data in horizontal wells remains a significant challenge. In highly deviated and horizontal wells, production-log job planning, which considers the combination of production logging tool sensors and data analysis methods, is a key factor for obtaining accurate information concerning the behavior of well fluids, formation characteristics, and the extent of well-completion mechanical problems.
The objective of this paper is to share the results of measurements taken from new production logging sensors and analysis methods with production data. These results were used to appraise the efficiency of the tool string by evaluating the acquired data and validating the analysis outputs along with the interpretation conclusions of the production efficiency. The "new-to-the-industry" analysis method consists of integrating multi-probe sensor data, including spinner calibration, superficial-phase velocity calculations, and phase hold-up measurements in a continuous wellbore environment.
While the acquired data has shown valuable information concerning fluid types, fluid compositions, and fluid velocities in these different flow environments, the analysis method has provided a complete integrated interpretation with a more accurate production profile, which is required to properly monitor reservoir performance and diagnose well-production problems.
Efficient Reservoir Simulation Post-Processing
Authors: Frost R. J. , Talbot N. R. , Al-Darrab A. M. , Hajjar O. F. 
Published: September 2011

Abstract
The volumes of data generated by modern reservoir simulators can be huge. This leads to problems with CPU time and memory limitations when presenting the results for analysis. The issue is not just with handling the large arrays for massive 3D grids but also for the well and completion vectors, which can consume many gigabytes of disk space. The problem is compounded by the trend for many simulations of the same reservoir, whether for history matching or to explore multiple development scenarios.
A further issue is with data display. When the number of runs, wells, completions and timesteps gets large, it can be difficult for an engineer to assimilate the information — especially when comparing bulk simulation results with sporadic historical measurements.
This paper describes techniques to overcome these problems. We concentrate on well-related results such as rates and totals, and grid values in completed cells. These include recasting the results into a form suitable for direct access on disk, a load on demand architecture and lightweight in memory representations. In addition user interface ideas that concentrate information are presented.
Thermal-Poro Elastic Stress Effect On Stress Reorientation In Production And Injection Wells
Authors: Abou-Sayed Ahmed S. , Zhai Zongyu 
Published: September 2011

Abstract
Stress reorientation is an important issue for the refracturing design and candidate well design. The long term production/injection causes the stresses to reorient. The temperature differential and pressure differential induced thermal elastic stress and poroelastic stresses are the fundamental reasons for the stress to reorient. A model and numerical scheme are developed to study the effects of thermal differential and pressure differential on stress reorientation. In the model, thermal diffusion and convection is coupled with hydraulic diffusion to obtain the temperature distribution reflecting the cumulative impact. The effective poro-elastic and thermo-elastic stresses are obtained from 1-D displacement equilibrium equation in a radial system. The 3-D in-situ analytical effective stress is superimposed on the 1-D solution. By applying this methodology the 3-D deviated borehole stress model is greatly simplified. The method makes it practical to obtain the stress distribution at any given injection/production time. The thermal stress, poro-elastic stress effects on the stress reorientation are compared and evaluated. Field examples are presented and show that in some cases thermal plays an important role on stress reorientation. The quantified results of the model will give guidance on the fracture treatments and well plan.
NMR Stabilization and Relaxation in a Single Pass Provides Reservoir Solutions
Authors: Smith Charles , Ramakrishna Sandeep , Menendez Eli 
Published: September 2011

Abstract
Conventional reservoir calculations using resistivity and density/neutron porosity have long been the industry standard for defining reservoir characteristics. Calculating water saturation from these measurements is used in virtually every reservoir situation. Many reservoirs have not had straight-forward analysis characteristics, so various and complicated analysis techniques have been applied with varying success through the years.
In some cases, years were spent in characterization before the reservoir was adequately understood. This time and expenditure of resources drained capital from exploration to research processes and, therefore, produced many inefficient completion attempts in reservoirs that were incorrectly characterized as productive.
The great hope with the introduction of NMR tools to the industry was that reservoir answers could be established and used in an uncomplicated manner. Recent advances in technology of NMR responses have produced the ability to capture stabilization time and relaxation time in a single pass through the reservoir. Molecule stabilization time has been demonstrated to have a close relationship to the fluid type in the reservoir. The relaxation time has been characterized to identify fairly precise values of permeability with an excellent relationship to production.
A description of porosity, fluid type, and permeability are established with reasonable accuracy without the need for extensive manipulation of the results. This paper presents examples of logs in sandstone and carbonate reservoirs where this technique is applied. Effective porosity, fluid type, and permeability are all resolved accurately with excellent comparison to production results.
Reducing Safety Incidents While Lifting and Handling Drilling Jars: A Case Study
Authors: Evans Chad D. , Reitsma Rienk , Ramsay Euan 
Published: September 2011

Abstract
The handling of drilling jars can present safety hazards when they are being serviced, transported, loaded or unloaded, handled on the rig floor, run in hole or racked in the derrick. Dangers are especially prevalent if the drilling jar is not equipped with a mechanical locking device. These tools present a potential hazard to personnel because of the possibility of inadvertently activating the jar.
Previously, this issue has been addressed by using an externally installed clamping device which is attached to the jar to lock it open and prevent an unplanned activation. If the clamping device is not properly installed, it can become a dropped object hazard. In response to the potential hazard of a dropped object from the derrick, some drilling contractors have elected to lay out jars from the Bottom Hole Assembly, BHA, on every trip. This in itself adds time to the operation and additional exposure to personnel.
The drilling jar safety clamp has evolved in design and material selection. The industry has evolved to a composite design, which reduces the element of operational error thus reducing the chance of a dropped object in the derrick and improved handling.
The composite design is much more reliable and easier to handle but has failed to eliminate the dropped object hazard. Following extensive risk analysis of the existing clamp, an innovative approach has been conceived in the form of an internal latch mechanism which can eliminate the requirement for an external clamp and provide more effective control of the jar while eliminating a possibility of an object being dropped in the derrick.
In this paper, the authors will review the safety hazards associated with the handling of drilling jars. They will describe the evolution of the external clamp, which is the main device in use. The paper concludes with a detailed discussion of the internal latching device that has been developed in the continuing effort to enhance the safety of drilling operations.
Mitigating Flow Assurance Challenges in Deepwater Fields using Active Heating Methods
Authors: Thant M.M. Myo , Sallehud-Din M.T. Mohd , Hewitt G.F. , Hale C.P. , Quarini G.L. 
Published: September 2011

Abstract
Flow assurance challenges, mainly of hydrates and wax depositions, are amongst the key issues that must be resolved and mitigated to ensure that hydrocarbons can be efficiently and economically transported from well to processing facilities. As wells step further away from shore into deeper water, the flow assurance challenges are increasing tremendously due to prevalence of higher pressure and lower temperature conditions. Thus, the development of cutting edge technologies to cater for the ever increasing demand in exploring the hostile and technologically challenging deepwater fields is a matter of great urgency.
One of the effective solutions to prevent the formation of wax or hydrates is to use active heating methods. This paper describes an overview of the available active heating methods and mechanisms which are being implemented as thermal management systems for flowline in deepwater fields. It also discusses the thermal performance calculation models available to aid the design and modelling of such systems.
Some comparative studies are carried out to determine the advantages and disadvantages of each of the methods to establish a general reference source on the technology that provides the most significant economic impact without compromising the reliability and efficiency of the overall system. Active heating systems have been used in several projects in the North Sea, Gulf of Mexico and Offshore West Africa. This paper also summarizes these projects and their operating experience from open literature.
In general, due to their operational flexibility and high efficiency through control of the pipeline temperature above the hydrate formation and wax deposition temperatures, active heating seems to be the most practical, economical and viable solutions in managing flow assurance issues; especially for the development of deepwater fields.