bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rotary Steerable System Applications in the Middle East
Authors: Pratten Charlie , El Kholy Khamel , Naganathan Sivaraman , Sharaf Ehab 
Published: December 2007

Abstract
Rotary Steerable drilling systems have led to a step change in drilling performance in many areas of the world. However their use in the Middle East has generally been slower to develop than in other drilling provinces around the world such as The North Sea where the value of rotary steerable drilling has been documented since 19981. Commercial as well as technical issues have limited widespread deployment of these systems in the region. This paper reviews successful rotary steering applications in the Middle East to date and explores areas for potential increased use.
Using case studies the paper looks a range of specific applications where the change from steerable motor to rotary steerable system has been both technically and commercially successful in the Middle East. Through these case histories the paper will demonstrate both tangible and intangible benefits resulting from the use of rotary steerable systems that have led to a step change in overall drilling performance in the Middle East.
Enhancing Rig Site Risk Awareness
Authors: Coakley Brian , Baraka Choaib , Shafi Mohamed 
Published: December 2007

Abstract
NDC has very successfully implemented an Unsafe Act (UA), Unsafe Condition (UC) and Near Miss (NM) reporting system. Over 20,000 reports are currently generated per year from the twenty four rigs which NDC own and operate.
These UA, UC and NM reports are reactive. Hence two additional systems, Behavioural Safety Auditing (BSA) & CHECK have recently been implemented. These provide a proactive input to prevent future NMs. In addition NDC are currently developing the SAP network to provide on-line HSE event tracking.
This paper presents how three systems can be run in parallel to provide comprehensive rig site risk awareness coverage. It describes how a multiple system approach to risk awareness avoids gaps and a reporting network allows all sites access to all reports.
Under Balanced Drilling Building the Future for PDO
Authors: Eissa Walid , Al-Harthi S. 
Published: December 2007

Abstract
Petroleum Development Oman LLC is one of the leading oil companies in the Middle East with a long history of early utilization of new technology. The cumulative production from its fields to date runs into millions of barrels of oil, with production starting back in 1967.
Drilling in PDO's mature fields using conventional drilling methods has become a challenge these days as severe reservoir impairment has been seen in Nimr and Saih Rawl fields. Much of this impairment is due to high overbalances resulting on the low reservoir pressures. Other problems were high water cut above that predicted from logging while drilling (LWD) evaluation. Underbalanced drilling (UBD) was identified as a method of overcoming this problem.
UBD trail wells have been drilled using 2 different UBD techniques (Concentric casing and Drill pipe gas injection). To date 18 UBD horizontal wells have been put onstream: 14 horizontal single lateral wells in the Nimr Field (12 new wells and 2 re-entries); and 4 horizontal multi lateral (total of 9 legs) UBD wells in the Saih Rawl Field.
Significant productivity improvements have been observed, and valuable reservoir data has been gathered during the drilling of these wells. Drilling performance has also shown marked improvements. This paper is written to highlight the key learning points which have been captured and applied in the UBD campaigns.
A Productivity Tool for Impact of Filtration on Well Performance in an HP-HT Environment
Authors: Amish Mohamed Belkasem 
Published: December 2007

Abstract
In recent times, the oil industry has shown increasing awareness towards maintaining optimum well productivity through better HP-HT drilling/completion fluids design. However, the mechanisms of drilling fluid filtration and impact on productivity performance are not well understood, especially in an HP-HT environment.
In open hole completions the productivity losses are critical because the near-wellbore damage is not by-passed by perforations.
Furthermore, a satisfactory model for field applications to simulate the near-wellbore damage in terms of well flow performance from laboratory core test analysis still is not available.
In this paper, the results of in-depth experimental research into rheology, filtration and formation damage phenomena and the relationships between them. The experimental data combined with data analysis of static and dynamic filtration models provided the database for the semi-empirical mechanistic models that were developed. These models have been combined and incorporated into a design and evaluation tool - the productivity tool, for predicting the effect of HP-HT drilling fluid filtration on formation productivity.
A number of results have been presented to illustrate how the new tool can be used to evaluate the damage factor of a given fluid, specify the invaded zone skin as well as the depth of invasion, two key parameters that are useful and relevant to optimum fluid selection and management in addition to well test data interpretation.
Prediction of the PVT Data using Neural Network Computing Theory
Authors: Goda Hussam M. , El-M Shokir Eissa M. , Fattah Khaled A. , Sayyouh Mohamed H. 
Published: December 2007

Abstract
Artificial neural networks theory creates, with other theories and algorithms, a new science. This science deals with the human body as an excellent source, through which it can simulate some biological basics and systems, to be used in solving many scientific, and engineering problems. Neural networks are tested successfully in so many fields as pattern recognition or intelligent classifier, prediction, and correlation development. Recently, Neural network has gained popularity in petroleum applications. In this paper we applied this technique in PVT parameters determinations.
The application interests in the estimation of the bubble point pressure through a designed neural network. As this value well estimated, it then used with other variables in a second network to determine oil FVF at this value of bubble point pressure. A comparison study between the performance of neural network and other published correlations has shown an excellent response with smallest absolute relative average error, and highest correlation coefficient for the designed networks among all correlations.
Laboratory Evaluation of Chemical Grouts for Wellbore Stabilization
Authors: Li D. , Chen G. , Chukwu G. A. , Patil S. L. , Khataniar S. 
Published: December 2007

Abstract
Wellbore drilling in highly fractured and unstable formations has always been one of the greatest difficulties in drilling operations. Failure and collapse of wellbore wall frequently occur in the fractured zone and may ultimately obstruct any further drilling of the wellbore. A number of techniques have been proposed and tested to improve drilling conditions in the fractured and unstable formations, but a highly effective method is still lacking. For many years chemical consolidation techniques have been studied and applied for ground support in underground mine openings. Very successful results have been achieved employing the techniques to stabilize fractured zones surrounding underground openings. For these a number of highly effective chemical materials for consolidation have been developed.
In order to examine the feasibility of this technology for enhancing wellbore stability, a series of laboratory experiments have been carried out in this study. These experiments included uniaxial compressive strength tests, triaxial compressive strength tests, shear bond strength tests, indirect tensile strength tests and thick wall cylinder tests. Chemical grouts Terraset B1000, Webac 4110 and others were used in these tests and their mechanical properties were assessed. The results of the experiments show that chemical grouting is likely to improve the stability of wellbore in fractured and unstable rock formations. Among the grouting materials tested, the Webac 4110 had the best performance. Its use increased the shear strength by 100-150%.
Real-Time Dip Applications for Geosteering Horizontal Wells, Onshore Nigeria
Authors: Ingebrigtsen E. , Onyirioha R. , Garrity J. , Logan J. , Butt P. 
Published: December 2007

Abstract
Geosteering is the interactive placement of a wellbore using real-time geological criteria; its use allows increasingly more complex geologic targets for horizontal producers and injectors.
This paper presents a case study of Geosteering horizontal wells in an onshore field of the western Niger Delta. The results demonstrate how an integrated team uses modern LWD tools to make real-time well path corrections in a challenging environment.
The objective of geosteering is to direct the well using real-time logging and interpretation to a specific target within the reservoir. Various best practices are discussed in which geologic and structural data are combined with LWD measurements to lower the risk of "landing" and subsequently maintain the horizontal portion of the well in the desired location.
Real-time dip estimation is a tool in the geosteering arsenal that can assist with geosteering decisions both during landing and while maintaining the lateral portion of the wellbore in the target window. Field examples illustrate the use of azimuthal density measurements to enhance real-time evaluation and decision-making processes. Quadrant density measurements and density images are used to calculate dips and enhance steering decisions made by an asset team of geologists, petrophysicists, and geosteering engineers for a field development project in Nigeria.
Present methods in geosteering for real-time dip estimation include interpretation of resistivity and density images, estimation from the quadrant density log, and detailed stratigraphic correlation during approach hole drilling. Associated with each estimation method is an inherent uncertainty with the dip calculation; these uncertainties can lead to geosteering decisions of low confidence. To reduce the total uncertainty, more than one method for calculating dip can be used to assist with well plan adjustments. The thinner the sand is, the tighter the steering tolerance becomes, requiring the well to be drilled closer to bed or target boundaries. The most accurate possible dip estimation is needed for these cases.
Incident Analysis using the Root Cause (Tripod Beta) Methodology-An SPDC Experience
Authors: Otutu F. , Agba S. 
Published: December 2007

Abstract
The Root cause analysis, called the Tripod Beta, is an approach to the analysis of incidents using the Tripod theory of Accident causation and the hazard and effect management Process (HEMP). This approach was adopted few years ago to stem the increasing rates of serious HSE incidents in SPDC and the advantages can be seen.
The pattern of previous incident investigation has been the same-the discovery that an incident happens always puts an end to the investigation, as if there is no need to look further-no need to see that such incidents are the effects of other causes.
The root cause (Tripod Beta) tool is a tree approach to the analysis of accidents and incidents. The method will lead you to take both short term immediate corrective actions, as well as finding the underlying root causes (latent failures) hidden in the way we do our work that will cause similar problems in the future. The Tripod Beta promotes thorough incident investigation with clear, concise and consistent reporting.
This paper presents the SPDC experience using this tripod Beta method in carrying out incident investigation/analysis and the incident trends (since adopting the method) and advantages will be highlighted
Using Production Logging Technology for Reservoir Management in the Persian Gulf
Authors: Alaeddin E. , Maizeret P. -D. 
Published: December 2007

Abstract
Is it a good idea to drill dual-lateral wells in a differentially depleted carbonate formation? The question is difficult. However, a state-of-the-art production-logging tool brought an answer that sanctioned the re-entry drilling program of this offshore field in the Persian Gulf.
The new-technology production services platform equipped with eight electrical e-probes for flow- imaging capability was run on coiled tubing for the first time in this offshore field to characterize the production of a new dual-lateral well. The main objective was to evaluate the total contribution of the horizontal drains. However, since the well was perforated in the different layers crossed by the well path, another critical objective was to determine the need for a stimulation program or a new completion design. Reservoir pressure in the different layers was expected to be non-uniform, so an additional objective of the logging operation was to obtain information on the differential depletion.
Production logging in highly deviated wells is difficult with standard sensors. One reason is that a conventional tool using differential pressure cannot measure fluid density. Moreover, flow regimes can be extremely complex, giving rise to phenomena such as water re-circulation, which is common in slanted wells and impossible to measure with a simple production logging string.
The data showed that both legs are contributing equally to the total production and observed water re-circulation on the bottom of the well. The perforations are not contributing to the total flow. Moreover, a crossflow observed during shut-in conditions suggested different pressure levels in the two layers.
This paper describes the logging operation and discusses how the results helped optimize the re-development plan of this aging field.
Opportunities and Challenges of an Integrated Energy Policy for Nigeria - Perspectives from a Competing Energy Product
Authors: Nwasike Obi Timothy , Gregory Oranugo 
Published: December 2007

Abstract
Until recently, policy and decision makers in Nigeria have neglected the socio-economic and commercial benefits that will accrue from the re- vitalization and re-development of Nigeria’s coal industry. This position is largely due to the lack of a clear energy policy that articulates the role and scope that each of the various energy media should play in our national development and in meeting Nigeria’s long-term goals.
Recent technical and economic studies have identified coal energy as a cost effective solution for power generation; it comes at a cost that is about 50% that of fuel oil. Furthermore, with over two billion tons reserves in Nigeria, coal is an abundant domestic resource that can support the mining industry and provide numerous jobs with potentially high multiplier effects on the local economy. Current technologies allows for clean burning of coal, which takes care of its negative environmental impact; indeed over 50% of the US electrical power supply is from coal resources.
This paper addresses the need to have an integrated energy policy that will define the role and scope to accommodate the various energy media available in the nation with the aim of promoting a broader development of and utilization of Nigeria’s many natural energy resources. With some emphasis on the place of coal as a viable energy resource, it also provides a clear evidence of the scope to apply knowledge and expertise from hydrocarbon sub-surface systems development, in this emerging industry sector. An outline of the key features of a possible integrated energy policy framework is also presented.
Lower Miocene Sequence Architecture in the Central Swamp Depobelt of the Niger Delta: Impact on Production
Authors: Ebong U. 
Published: December 2007

Abstract
The Lower Miocene strata of the gas-rich X, Y and Z oil fields in the Central Swamp depobelt of the Niger Delta, is evaluated in terms of its sequence stratigraphic architecture. The penetrated interval includes three superimposed estuarine valley-fill sequences (S1: 17.7Ma-16.7Ma; S2: 16.7Ma-15.5Ma; S3: 15.5Ma-13.1Ma). Apart from Field Z where S3 includes a lowstand systems tract, each valley-fill contains a fluvio-estuarine transgressive systems tract (TST) and a highstand systems tract (HST). This stratigraphic architecture appears to have a strong influence on reservoir properties and petroleum resource distribution. The bulk of the total original oil in place in Field X and Field Y, which occurs in narrow, wedge-shaped, discrete/amalgamated, proximal fluviatile-distal marine sand bodies encased in marine shales, are restricted to the 17.7Ma-17.4Ma transgressive estuarine valley fill of S1. In Field Z, the productive reservoir consists of alternation of detached shoreface sand lobes and outer neritic-bathyal shale. This reservoir occurs within the 15.5Ma-15.0Ma lowstand and transgressive systems tract of S3. Highest quality and greatest degree of homogeneity are indicated for Field X and Field Y reservoirs. Sand body geometry and heterogeneity in internal architecture of Field Z reservoir account for the more complex lateral and vertical fluid flow reported from this field.
The new knowledge of the depositional characteristics of the reservoirs and the genetic relationship among the oilfields minimises geological and dynamic uncertainties in the inter-field development plan.

Introduction
The sequence stratigrphic concept provides an excellent tool that addresses the problems of genetic relationships among oilfields and reservoirs, as well as sand development and property distribution. This report which focuses on the Central Swamp depobelt of the Niger Delta, evaluates the sequence stratigraphic architecture of X, Y and Z oilfields (Fig. 1). The three fields were discovered in 1971, 1966 and 1961 respectively. Field Y is separated from Field X to the north, by a major fault and from Field Z to the south by a macrostructure-bounding fault. Each of the three fields contains one major oil reservoir (Field X-E1, Field Y-D7 and Field Z-E2 reservoirs respectively) at depths between 10,000ft and 12,000ft below the surface.
The genetic relatioships of the three fields has remained a matter for speculation. Water injection was started in Field Z in 1981, but was discontinued in 2001 due to inexplicable water losses and persistent steep drop in pressure. To account for this, some schools of thought have speculated that the three major reservoirs might possibly be connected. It was therefore imagined that if production in the more proximal Field X and Field Y caused pressure drop in the more distal Field Z, a common production strategy could be adopted for the three fields.
Successful Matrix Acidizing: Is Guess Work Part of Your Design? Good Engineering Mitigates Uncertainties
Authors: Enelamah Uzodinma C. , Akunna Patrick O. , Poitrenaud Hugues 
Published: December 2007

Abstract
The global demand for oil and gas is expected to rise by an estimated 2-4 percent annually over the next decade while production decline from matured fields is estimated at about 5 percent annually. Well productivity enhancement through stimulation provides a cost-effective way of increasing production, especially in matured fields. This provides both an opportunity and a challenge. The worldwide success rate of matrix acid stimulation has been occasionally reported as low at 20% in some areas, with most operators reporting approximately 50% to 75%.
Case histories of a number of matrix acid treatments of several wells in the Niger Delta, some of which were successful and some of which were not, seem to indicate that the success of a treatment is not a matter of chance. All the successful treatments had one thing in common: they were not only producing with high skin, the damaging material was recognizable and removable. Unsuccessful treatments also had quantifiable skin and the damage mechanism had been identified (to be migrating formation fines), however, the mineralogy of the damaging material had not been accurately identified.
This paper describes the engineering process used to mitigate the uncertainties involved in sandstone acidizing and maximize success rate, including candidate selection criteria, treatment design, and post job evaluation. The paper also presents the key lessons learnt from the case histories and recommendations for future treatments.
Recognition of Sedimentary Facies and Deformation from Borehole Images in Deep-water Environments - Applications from Offshore Nigeria
Authors: Lawrence D. A. , Ros J-B. , Vandenabeele T. 
Published: December 2007

Abstract
Borehole image logs in deep-water turbidite reservoirs have often been used with limited success in sedimentary facies recognition, since many wells are drilled with oil-based muds preventing the use of high-resolution resistivity imaging tools. This paper presents the successful application of acoustic images (UBI1), oil-based dipmeters (OBDT2) and more recently oil-based micro-resistivity images (OBMI3) in enhancing deep-water reservoir evaluation with examples from offshore Nigeria.
Specific aspects highlighted in this evaluation are lithofacies discrimination, syn-sedimentary deformation and structural applications. Continuous ‘image facies’ interpretations, calibrated initially with core, were generated over the entire reservoir-bearing intervals and compared with conventional ‘electrofacies’ identification from wireline logs. A variety of syn-depositional deformation features are recognised, including slump folding, slide blocks and sandstone injection. Careful calibration with seismic, including generation of scaled seismic overlays of dip data, significantly enhances well to seismic calibration and highlights sub-seismic faults that may have been overlooked in reservoir model construction.
This paper highlights the value of borehole image logs in deep-water reservoir analysis, particularly when fully integrated with core and seismic data. Some implications for reservoir model construction are also emphasised.
Integrated 3-D Static Reservoir Modelling of an Onshore Niger Delta Field using Well and Analogue Data
Authors: Iwegbu J. C. , Arochukwu E. C. 
Published: December 2007

Abstract
The interpretation of depositional environment and prediction of reservoir properties in oil fields, where there are no cores, have always been characterised by a lot of subsurface uncertainties. The interpretation of the environment of deposition on the basis of log signature alone increases these uncertainties. This paper shows how the uncertainties in interpreting the environment of deposition were reduced by the integration of data from different sources. It also describes how the interpretation was used in predicting the reservoir properties across the field, thereby enabling the successful modelling of two reservoirs in a field that did not have core data.
Is "Live Annulus" Data Interpretation During Frac Pack Operations Viable Information
Authors: Hale C. L. , Conrad M. A. , Bose M. T. , Parker C. V. 
Published: December 2007

Abstract
The technique of using a "live annulus" for data collection analysis during frac pack sand control completions has evolved quite extensively over the past few years. Field case studies have revealed several anomalies in this data collection and analysis.
The following discussion covers more than 100 wells completed in the Gulf of Mexico using mini frac data analysis on both the workstring and "live annulus" data and their relationship to the bottomhole gauge data. The ability to incorporate this "live annulus" data has been facilitated by downhole tool development.
The use of "live annulus" data has been viewed by many as being the single most important factor in the successful interpretation of pressure analysis during frac pack operations. Certainly, the elimination of friction in trying to interpret real time data enhanced the ability to make "on-the-fly" decisions. Having a "live annulus" also may help in overcoming some of the water hammer problems in rapid closure situations. However, caution must be used in relying on "live annulus" data. A close look at this summary of data completed in the Gulf of Mexico highlights the need for this caution and questions the degree of it s use.