bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulse-Test Interpretation for Badri Field
Authors: Mahmoud M. L. , Torre A. J. , Ayan Cosan 
Published: December 2007

ABSTRACT
This paper shows the results of a Pulse Test conducted in Egypt's Badri Field. The test was conducted to understand the degree of hydraulic communication within the reservoir and to check a suspected fluid migration towards the nearby El-Morgan Field. The test involved 6 wells, including the active well. The pulses were created by an alternate sequence of injection and shut-in periods of 36 hours each. The resulting pressure pulses were monitored in the observation wells for 12 days.
The observed pressure responses were analyzed by history matching techniques. The analytical solution of the diffusivity equation for a homogeneous rectangular reservoir with mixed boundary conditions yielded an excellent correspondence between measured and simulated pressure responses.
The test indicated good hydraulic communication within the investigated area. It also showed that there was no leak towards the neighboring El-Morgan Field as it was previously anticipated. In addition, it was possible to determine the interwell -reservoir properties and the geometry of the area investigated during the test.
The test also suggested the presence of free gas in the upper part of the structure. This was confirmed by other sources of information.
Geometrical Characteristics and Geological Modelling of Fractured Middle East Reservoirs
Authors: Nurmi R. D. , Standen E. J. W. , Akbar Mahmood 
Published: December 2007

ABSTRACT
Fracture geometry and basic characteristics (orientation, length, density, aperture, porosity) of fractures in a number of Middle East reservoirs (from Egypt to Pakistan), have been recently studied. These studies confirm that fracture orientation, distribution and characteristics important to reservoir behaviour do not vary randomly nor chaotically. Moreover, there are commonly lower densities of fractures in reservoirs than are seen in the same formations outcropping at the surface. The simple cubic models used in reservoir studies, are sometimes appropriate for reservoir studies but often more complex geometric models are needed.
The factors which determine the occurrence of natural, open, permeable fractures within Middle East reservoirs are nature and degree of folding and/or faulting, in-situ stresses, and changes in rock properties such as porosity, bedding, and lithology, especially shaliness. These geological factors can and are often already mapped in reservoir studies. By accurately defining the relationship of these various factors to the fracturing analyzed in a number wells within a field it becomes possible to extrapolate the fracture data through out a reservoir.
There is no routine direct evaluation of fracture porosity and permeability available at the present time. However, borehole imagery allows the fracture porosity and flow potential to be calculated by multiplying the fracture density and the aperture widths measured using a modelling package available on a computer workstation. The use of aperture and fracture density data to also calculate permeability (approximately the value of the fracture aperture cubed) means that fracture aperture and density are critical parameters in defining the reservoir potential of a fracture system intersected by a well bore. The observations concerning the variations of the major fracture characteristics especially aperture and density along with orientation are summarized.
The short-coming to fracture studies using either borehole imagery or oriented cores, however, is that the fractures detected may not be representative of the large-scale fracture network which will determine reservoir production. Thus, it is necessary that the geometrical characterization of any borehole data be related to geological studies (structure, stratigraphy, sedimentology, diagenesis, and geostatistics) of that reservoir.
The borehole-scale characterization and the geological modelling also need to be integrated with the dynamic testing and production data more than just compared as a type of quality control. Even when they are radically different, both sets of data may be correct. In fact, how the two types of data fit is a key to proper modelling of the reservoir.
Comparison of Petrophysical Method for STOIIP in a Refined Estimation of Fractured Basement Reservoir
Authors: Khalil M. M. , Pigaht Joerg , El Wazeer F. M. 
Published: December 2007

ABSTRACT
The fractured Basement reservoir is considered as one pf the most difficult rocks to be evaluated due to its heterogeneity.
Extensive information is available in the literature concerning techniques to evaluate naturally fractured reservoirs in general. Little is known however, about approaches to calculate porosity and water saturation in fractured basement reservoirs with little or no real matrix porosity.
SUCO's Zeit Bay field is producing from the fractured basement as well as overlying sedimentary rocks. Evaluation of STOIIP in the Basement proved difficult, due to the problems of taking cores and to the low level of porosity expected in a naturally fractured rock.
This paper compares several tools and techniques used in the Zeit Bay field with a view to narrowing down the STOIIP estimation for this field. Due to the highly fractured nature of the Basement rock in this field, fracture porosity is estimated higher than usually expected in naturally fractured rocks. Core material recovered is, for the same reason, only recoverable from less fractured regions, i.e. less porous intervals. To supplement the sparse amount of qualitative core data, porosities were calculated from a comprehensive log analysis and from Formation Micro Scanner Data using a conventional approach as well as a "Fracview" interpretation.
Interpretation of the Array Sonic for the Stoneley wave is used for permeability identification.
Correlation between all available data is presented and their use for porosity or permeability estimation highlighted.
Critical comments are made on all approaches and results are shown on a comparative basis, with the view to narrowing down the porosity range for this reservoir rock.
Geostatistical Application for Exploration and Development: Porosity Estimation from 3-D Seismic Data Calibrated to Well Data
Authors: Chambers R. L. 
Published: December 2007

Abstract
The geostatistical external drift method is used to integrate 3-D seismic data into a reservoir description and is illustrated with an application on a west Texas Permian Basin interbedded carbonate-clastic reservoir. Seismic reflection amplitudes, calibrated to core and sonic-derived porosity data, supplements sparse well control to estimate interwell porosity.
An extensive well log and core data base was subsampled over a small portion of the field covered by a high resolution 3-D seismic survey to mimic scenarios similar to three stages in a reservoir's life: (1) a 7 well case, typical of a late exploration/early appraisal phase; (2) a 14 well case, similar to a development phase; and (3) a 55 well case (40-acre well spacing), representing a mature production phase.
Spatial interpolation by kriging porosity with and without seismic data are compared. Stochastic (Monte Carlo) simulations are used to evaluate interpolation uncertainty (standard error), a quantity not obtained from kriging. Interpolation uncertainty is greatly reduced when seismic data are integrated into the reservoir description.
Representing Fine-Scale Heterogeneities in Coarsely Gridded Models
Authors: Williams G. R. , Lockwood R. P. 
Published: December 2007

ABSTRACT
An example of how fine scale heterogeneity was incorporated into a large full-field model is presented. A detailed geologic description was prepared and implemented in a 2D crosssectional model. The important heterogeneities in this reservoir were found to be shale barriers. A simple Markov method for modeling fine scale shales was developed. Stone's method for determining interblock relative permeabilites was superior to Kyte and Berry's method, in this case.
Calibration of Old Well Log Data Using a Multiwell Environment
Authors: Faqihi M. M. , Crossouard P. A. 
Published: December 2007

ABSTRACT
This paper reviews the implementation of a special multiwell calibration technique to transform and normalise old well data within a petrophysical study. One problem in the evaluation of old wells is the porosity calibration of the Neutron counts. This can be achieved through a normalisation program on a single well basis if another porosity measurement such as the Sonic log is available in the same well. In the case of this study two such porosity-dependent measurements were not available and a new variable was needed to link old and new data. However, good log correlation in the field and the availability of a multiwell data base set-up allowed the use of log depth as this extra dimension.
Old data is imported into new well data and is automatically tied to them. This is done by extracting from the Multiwell Data Base the formation tops of old and new wells and by depth-shifting the old well data by an amount equal to the difference between the formation top depths. Then an auto-correlation depthmatching program using comparable curves such as old and new Gamma Rays refines the tie between wells.
Having linked the data through a common depth, a multiwell cross-plotting technique gives the best fit between old and new data. The best fit equation calibrates the old data and this is validated quickly against field trends using multiwell crossplots
To account for the different sensitivity of the GR detectors as the technology of logging tools has evolved, the same calibration technique can be applied to rescale the GR data of the old wells. This re-scaling of the GR of old wells gives the same ranges as the GR of key wells allowing the use of multiwell histogram/ estimation programs and the use of similar interpretation parameters throughout the field.
The old log data was successfully calibrated allowing their use as input to modem log evaluation packages.
For each old well the multiwell evaluation set-up gave easy calibration against one or several recent nearby wells and it ensured quality checks of the results. The technique can be used to integrate older data into a study, giving the more detailed coverage needed for reservoir characterisation and simulation work.
Customer/Supplier Cooperation: Working Together for Quality
Authors: Robins K. B. , Carlisle J. A. 
Published: December 2007

Abstract
This paper describes the impact on Total Quality Management (TQM) that improved customer/supplier relationships have had for a UK Exploration and Production Operator. The Drilling in the Nineties initiative introduced in early 1990 has been broadened to include well services and equipment supply areas with a resultant name change to Well Engineering in the Nineties (Win 90s). Experience has been gained with the implementation of this programme with two drilling contractors.
In E & P companies the focus for TQM improvement is invariably on the supply side, ie the well and production, unlike other industries where the focus is on the customer. Quality in E & P is thus driven, not by the end user; but by upstream (supply) pressure, for reasons of cost, safety and the environment.
The implementation of co-operative supplier strategies is increasing the demand for Total Quality Management in both supplier and customer companies.
The paper will describe how developing a co-operative relationship has resulted in a joint effort in initiating more continuous improvement activity, reducing waste and adding value.
Examples are discussed of appropriate planning and training initiatives and tools used to develop a co-operative relationship. The need for support and intervention from senior management such as modifying existing policies to support the new relationships is reviewed.
Win 90's implementation has shown that it is not the introduction of Total Quality Management with the operator or supplier individually but the integration along the supply chain which enables ‘leading edge’ performance.
A Monte Carlo Model for Pressure Transient Analysis
Authors: Baldwin D.E. 
Published: December 2007

Abstract
This paper describes a simple numerical model for simulating pressure behavior in petroleum reservoirs. The numerical procedure, which is based on a modification of the Monte Carlo technique, is extremely accurate and results in a significant saving in computation time over conventional finite difference methods.
The mathematical development of the Monte Carlo method and its implementation for pressure transient analysis are described in the paper. In addition, the general applicability of the method is illustrated by test cases involving a variety of pressure transient problems.
Introduction
Monte Carlo, or random walk, methods for solving partial differential equations are well known partial differential equations are well known and have been in use for over sixty years. Although the methods are simple and offer a number of advantages over conventional finite difference techniques, they suffer from excessive calculation time and the inaccuracies associated with probability sampling, A recent modification probability sampling, A recent modification of the classical random walk technique, known as the Exodus Method, has eliminated many of the computational disadvantages associated with Monte Carlo methods and has made them an attractive approach to the solution of certain classes of problems. In particular, pressure transient problems, where solutions are required at a selected point rather than over the entire finite grid system, are admirably suited to this technique.
This paper details the development and application of the Exodus Method for transient analysis and presents the results of computational experiments which were performed to evaluate the effectiveness of the resulting numerical model.
MODEL DEVELOPMENT
The flow of a slightly compressible fluid in a porous medium of non-uniform permeability is porous medium of non-uniform permeability is governed by the following equation:
(1)
Building a Drilling Partnership
Authors: McKee J. D. A. , Brandt W. H. 
Published: December 2007

Abstract
A movement away from conventional day rate contracting towards partnering and closer customer supplier relationships has been initiated with the advent of Well Engineering in the Nineties (Win 90s). This initiative is changing the traditional role of the drilling contractor and the drilling service companies. The drilling contractor will become the lead contractor for the provision of drilling services, and together with it's subcontractors will assume more control, accountability and risk associated with the drilling operation. As these responsibilities are handed over, the performance of the operator will become critically dependent on the performance of it's suppliers, and the development of a partnership between the operator, drilling contractor and drilling service companies with close customer supplier relationships and sound supply chain management will assume greater importance.
This paper describes how a drilling contractor has assumed the role of lead contractor and is developing long term, co-operative relationships with preferred service companies to provide a drilling service for Win 90s operations. The paper discusses the contract structures, procedures for selection of suitable service companies, and how to develop a business process plan for managing the changes to the drilling process. Integrating the services and the application of incentives to focus on the operator's needs is also addressed. It also examines the progress to date in implementing the new contracts and the business process plan, and summarises the successes and failures of the work so far.
Safety Management at Start-Ups is Key for Short-Term Drilling Contracts
Authors: Lievre Thierry 
Published: December 2007

Abstract
A fall of the drilling activity and a shortening of the drilling contracts were experienced during the past few years, in both offshore and on land activities throughout the world, ranging from European to desert areas. These together with the development of integrated services and turnkey contracts have had a considerable impact on the responsibility for safety by the drilling contractor. Furthermore, the safety management systems have become more sophisticated and the expectations-from all parties-for safety performances have increased. The assistance of safety professionals has become necessary on site to enable the application of this developing expertise and accomodate the additional workload. Their role must now be considered to be a primary component to the safety organisation.
A Simple Correlation To Predict the Hydrate Point Suppression in Drilling Fluids
Authors: Yousif M. H. , Young D. B. 
Published: December 2007

ABSTRACT
Gas hydrate formation during deep-water offshore drilling is a well recognized operational hazard. At water depths in excess of 1000 ft[305 m], the sea-bed ambient conditions of pressure and temperature become conducive for hydrate formation. This can impose serious well control difficulties during the containment of a gas kick.
Salts and glycerol are the main hydrate inhibitors commonly used in water-based muds. To determine the required salt and/or glycerol concentration for a particular drilling fluid, costly and time consuming experiments are required.
This paper presents a simple correlation to predict the hydrate point suppression using mixtures of salts and glycerol. The correlation is based on rigorous thermodynamic principles and represents a substantial improvement over Hammerschmid's correlation. Example calculation is provided on how to utilize the proposed correlation.
The Design and Operation of the Support System Required To Operate a Cantilever Jackup in the Skidoff Mode for Tender-Assisted Drilling
Authors: Springett C. N. , Hinton R. O. 
Published: December 2007

ABSTRACT
Using a jack-up in the tender assist mode is not new. It has been done by several contractors in different parts of the world. It has become increasingly attractive from a cost standpoint in the Central North Sea and has been proposed for production drilling on a number of new developments. Cantilever rigs of newer design, while having greatly increased water depth capability and highly rated drilling equipment, do not lend themselves to easy conversion to the skidoff mode of operation as do the older slot type rigs.
This paper describes the approach that has been taken by Santa Fe in developing a system that is not only usable with any of their four new North Sea harsh environment rigs, but which will be compatible with the widest possible range of production platforms. The paper also focuses on the need for maximum flexibility in installation techniques. The transition structure (skidbase) supporting the drillfloor can be erected using a derrick barge, using rig cranes, using platform cranes or installed on the jack-up while in sheltered waters and skidded in one piece onto the platform. The unique capability of the resulting system is that it is fully self contained, complete and self erecting, all that is required of the production platform is two parallel capping beams with spacing less than 60 feet (18 metres). The paper is of wider interest and application in that it provides a blueprint for the conversion and outfit of virtually any cantilever jack-up to the tender assist mode.
Enhanced Drilling Efficiency through Operator/Contractor Cooperation
Authors: Cole J. C. 
Published: December 2007

Abstract
An innovative management structure utilized by Shell Offshore Inc. for the Auger predrill program permitted a close-working relationship between the various departments at Shell, Sonat Offshore Drilling Inc. (the drilling contractor), and the third party service companies. The result was a substantial improvement in drilling performance and a large increase in the scope of work completed during a 29-month period.
Use of Drilling Parameters to Predict In-Situ Stress Bounds
Authors: Hareland Geir , Hoberock L. L. 
Published: December 2007

Abstract
This paper reports theory, procedure and results on the use of drilling parameters collected during typical drilling operations to predict bounds on minimum principal in-situ stress of rock. These predictions are desired in order that hydraulic fracturability of reservoir rock can be better determined and fracturing programs designed without the need for expensive fracturing stress tests, guesswork, or empiricism. A high fidelity tri-cone roller bit drilling model is used in an "inverted" mode to predict in-situ ultimate compressive rock strength. This compressive rock strength is a function of effective confining pressure available from published laboratory data for various rock types. Knowledge of the compressive rock strength failure as a function of confining pressure can be used to obtain the Mohr failure envelope at a given depth for rock. The angle of internal friction is determined from the Mohr failure envelope, which can be used to calculate a "coefficient for earth at rest." This coefficient, together with known overburden and pore pressure, can be used to calculate an upper bound on the minimum horizontal stress for each foot drilled. The calculated in-situ stress bound profiles are compared, with good results, with experimental field closure stress data obtained in 46 tests in four GRI (Gas Research Institute) wells, SFE (Staged Field Experiment) wells #1,2, 3, and 4.
Power and Quality: Two Approaches to Service Company Support for the North Sea Oil Industry
Authors: Krahn D. R. 
Published: December 2007

Abstract
This paper examines 21 middle tier offshore service (SSSCM) firms. Three models explore their difficulties and suggest ways forward. First is Porter's Model of the CompetitiveEnvironment;second is J.K. Galbraith's Model of Countervailing Power; and third is a Composite Quality Model based on Deming, Juran, Crosby, and Feigenbaum.
Drilling in the Twilight Zone: Somewhere Between Dayrate and Turnkey
Authors: De Wardt JD. P. 
Published: December 2007

ABSTRACT
Dayrate contracts have been the normal mode for drilling operations for a long time. The environment is well known and therefore comfortable to the participants. The operator retains control over all aspects of the operations; essentially the operator leases men and equipment.
Turnkey contracts have been regularly utilised in the USA and have been used to a limited extent internationally. In their simplest and purest form they provide an understandable and usually clear assignment of responsibility to the contractor.
Dayrate contracts provide little incentive to perform, are professionally unrewarding to contractors' personnel and presently do not offer a profitable return on investment in most sectors.
Turnkey contracts, by contrast, provide a significant incentive to perform, are professionally rewarding to contractors' staff and can provide an environment whereby the contractor achieves a more profitable return on investment whilst the operator reduces well costs. Unfortunately, the application of the non variable turnkey contracts used today has been limited due to their inability to handle uncertainties and a reluctance of the industry to adopt this form of contracting.
As a result a significant movement has arrisen towards contracts which fall between the well known dayrate situation and the non variable turnkey.
This is the twilight zone – an ill defined region of major contrasts in control, responsibility, accountability and price. A region which requires thought and development to provide the mechanisms for successful contracts. A region through which the way forward to more meaningful contracting is being developed. The structure and orientation for contracting drilling operations in the twilight zone is developed in this paper.