bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the First Two Horizontal Wells in Egypt
Authors: El-Rafie E. A. 
Published: December 2007

ABSTRACT
Horizontal wells have been shown to increase productivity, reduce coining tendencies and increase recovery. Until few years ago, the usefulness of horizontal wells has been demonstrated only in North America and Western Europe. In Egypt, not since quite recently has there been several serious horizontal well projects under studies and planned to be drilled. Currently two horizontal wells have been drilled and put on production in Egypt.
This paper reviews the production and reservoir engineering aspects of these trial horizontal wells. Also it illustrates the comparison between the predicted and actual performance of these horizontal wells. Finally, the estimate of the expected critical rate from the horizontal well is compared to that of a vertical well to estimate the possible gain in rates.
In summary, the two wells, although one has not been successfully drilled for enough far from the contact level, has shown potential productivity around ten times that of a conventionally completed comparison well and further productivity increase in similar wells are thought to be possible.
Also critical coining rate comparisons between the vertical and the horizontal wells indicated that horizontal wells are quite suitable for reservoirs that are this, shown high vertical permeability and exhibit water coining problems.
Evaluation of the Effects of Multiples in Seismic Data from the Gulf Using Vertical Seismic Profiles
Authors: Fryer Andrew 
Published: December 2007

Abstract
Surface seismic data can be affected to varying degrees by multiples. However, the exact source and true extent of these multiples are difficult to determine with surface data alone. Vertical Seismic Profiles (VSPs), in which the depth of the reflectors is known, provide a full account of the source and magnitude of multiples. These results are directly applicable to surface seismic processing and to seismic interpretation.
Studies of data sets from the Gulf indicate that different types of multiples affect the seismic data. Long-period events are generated from a few strong reflectors, both shallow and deep. Their period, origin and strength can be directly determined from VSPs. Thinly-bedded, highly reflecting formations, such as the Lower Pars formation, generate short-period multiples, which can affect the shape of the wavelet.
The effects of the short-period multiples can be quantified from the analysis of the downgoing VSP wavelet. It was identified that there was a significant change in the phase of the downgoing wavelet as it passed through the Lower Fars formation. With further analysis of the data, it was shown that this accounted for a two-way travel time delay about 20 msec. A mistie of this magnitude could prove critical to the interpretation of the more subtle reservoirs.
A synthetic VSP was derived from a velocity model calculated from the openhole logs to confirm the effects that the short-term multiples have on the seismic wavelet. By processing the synthetic data in the same way as the measured data, it provided the analogy that short-period multiples are not only generated from within the Lower Fars, but also affect the behaviour of the downgoing wavelet. When the data was processed without the effect of multiples, there was no change in the phase of the propagating wavelet.
Effectiveness of Low-Salt Cement Opposite Salt Bodies
Authors: Ismail S. A. A. , Khalaf Fouad 
Published: December 2007

Abstract
High-salt cements (HSC) have been extensively used across salt formations, mainly because they are supposed to ensure effective bond-ing. However, HSC slurries have serious drawbacks: they require excessive wait on cement, develop late compressive strength, and have high free-water content.
This paper rehabilitates low salt cements (LSC) for use across mas-sive salt formations: LSC have excellent properties that warrart consideration for cementing pipe opposite "moving" salt bodies . For this purpose, conventional API cement laboratory tests were run on class "6" neat cement and on "6" cement plus 35% silica flour mixed with various salt concentrations in the mix-water. The tests compare the basic operational properties of slurry and set cement properties of HSC and LSC. The analysis of these tests shows that the properties of LSC are more effective than those of HSC, and are to be used opposite salts deeper than 3000 feet ss. Below that depth, early compressive strength becomes critical: it is essential for casing support and for stopping salt creep. LSC can be easily tailored to achieve good early compressive strengths that can help stop early salt flow.
Special Horizontal Completion Designs Enhance Running Procedures and Openhole Cleaning Techniques
Authors: Restarick H. L. 
Published: December 2007

ABSTRACT
Horizontal openhole completion equipment requires special design considerations for each application since every well presents a unique set of downhole conditions. Operators who drill horizontal wells must address problems such as frictional drag, screen plugging, openhole cleaning, key seating, and fluid loss that can occur during the final stages of well completion and compromise the efficiency of the well. By careful selection of tools and completion techniques, the operator can plan for successful management of these problems.
Environmental Aspects of Produced Water Disposal
Authors: Allen R. M. , Robinson Keith 
Published: December 2007

ABSTRACT
Within the oil and gas production industry there is an increased focus on the discharge of produced waters to the environment. That there is no universally agreed standard for oil-in-water discharge quality is partly an indication of the different capacities of receiving waters to absorb the pollutants. It is, however, compounded by a lack of any universally agreed methods even on how to measure oil-in-water, with, in extreme cases, results varying by orders of magnitude according to the actual methods used. In the future, it will be increasingly necessary to demonstrate that not only is the oil-in-water content acceptable but also that the water is non toxic. This toxicity can arise from dissolved hydrocarbons, such as benzene, heavy metals and perhaps even radioactive elements.
Performance of Horizontal Wells, Safah Field, Oman
Authors: Chen Hsiu-Kuo 
Published: December 2007

Abstract
This paper reviews the performance of seven horizontal wells completed between October 1990 and February 1992 in the Safah field, the Sultanate of Oman. The horizontal well sections range from 1985 to 4718 ft. The well performance indicates that there is no direct correlation between initial well productivity index (PI) and length of the horizontal section. The long-term PI of the horizontal wells depends on the GOR of the well. The average PI of the horizontal wells is about 10 times that of the average vertical wells. It takes about one fifth of the time to produce a given production with a horizontal well. The excellent performance of the horizontal wells has increased oil production. The use of horizontal wells is expected to increase the overall recovery for the Safah field.
Stress Around A Wellbore
Authors: Deily F.H. , Owens T.C. 
Published: December 2007

Abstract
A study was made of the stress state in a porous elastic body, with particular emphasis on variations in selected failure criteria. The objective was to relate predicted changes in stress and failure criteria with fracture initiation experienced in certain forms of lost circulation, as opposed to hydraulic fracture extension. The three principal stresses at the wellbore were expressed as functions of wellbore pressure; in addition, values of eight additional parameters were varied over realistically expected ranges to determine their possible importance on the principal stresses. These eight parameters were the three tectonic stresses, formation fluid pressure, pore pressure at the wall, Poisson's pressure, pore pressure at the wall, Poisson's ratio, the ratio of unjacketed to jacketed rock compressibilities, and position around the wellbore. Two failure criteria, the maximum principal stress and Von Mises number, were determined for the well stress condition chosen. Calculated results show that small changes (5%) in tectonic stresses can cause larger changes in wellbore stress (and potential failure) than very large (100%) changes potential failure) than very large (100%) changes in Poisson's or compressibility ratios.
Introduction
A theoretical investigation of the state of stress around a wellbore was made to study the problem of fracture initiation in a porous elastic body. This work was undertaken to determine the effects of rock properties, tectonic stresses, wellbore pressure, formation pressure, and mud filter cake on lost pressure, and mud filter cake on lost circulation in a drilling well.
The mathematical model chosen for this investigation is a large porous body containing fluid at a particular pressure, P. The body has a cylindrical hole which contains fluid at a pressure, Pw. In addition, the porous body is acted upon by external stresses, Sx, Sy, and Sz (see Fig. 1). The quantities Sx, Sy and Sz are the tectonic stresses and are considered positive when tensile. In reality, these positive when tensile. In reality, these stresses are compressive (negative). The vertical tectonic stress, Sz, is due to the weight of all of the overburden. It is generally accepted that the principal horizontal tectonic stresses are not equal because of the preferred fracture orientation that is noted preferred fracture orientation that is noted in a specific area. The wellbore pressure, Pw, is equal to the sum of the hydrostatic Pw, is equal to the sum of the hydrostatic pressure of the column of drilling fluid and pressure of the column of drilling fluid and the annular pressure drop due to the circulating fluid.
An Alternative Method of Installing ESP's
Authors: Robison C. E. , Cox D. C. 
Published: December 2007

ABSTRACT
Electric Submersible pumps (ESP's) traditionally have been installed on threaded pipe using workover rigs. More recently, however, three alternative methods for deploying ESP's have been presented. Two of these utilize a cable system and have been successfully demonstrated in the field. The third, overlooked until now, uses coiled tubing. Coiled tubing technology has continued to provide state-of-the art diversification in many areas of well-servicing technology, and the use of coiled tubing for ESP installations is a logical extension of these enhancements.
This paper contrasts coiled tubing ESP installation methods with cable-deployed methods.
Remarks on Exploration Tools: Integrated Exploration Strategy Being Applied to Carbonate Environments
Authors: Fischer Klaus , Holling Meinhard , Marschall Roland 
Published: December 2007

ABSTRACT
Applying an integrated exploration strategy requires two basic steps: -Establishment of database, containing the given observations-Development of model data base
The model here is defined as a tool to aid in organizing the given observations, and contains interrelated subgroups of detailed submodels. These submodels may be facies trends, velocity models, maps resulting from global log-correlations etc. Therefore the development of the submodels comprises the following steps: -Global basin analysis (uplift/subsidence, basin history, hydrocarbon potential, migration paths, data and the resulting 3D stratigraphic model, which forms the basis tor a reservoir model.trapping etc.)-Structural interpretation/sequence analysis of the given seismic data (2D or 3D), integration of non seismicdata like gravity, magnetics-Classification of intervals, facies trends for selected intervals, mapping of additional tops etc (ABIC-code), application of geostatistics.-Refinementlextension of mapped interfaces-Final depthing using improved velocity functions-Application of modeling tools / special processing techniques to improve resolution/ verify interpretation
In this article we discuss some aspects of carbonate settings being evaluated along above guidelines, where the following items are investigated: -identification of build ups-mapping of shelf trends-application of special processing tools such as L1- decon, AVO-analysis etc.-verification of shelf trends in terms of lithofacies units, i.e., their individual impedance values, by fifinite-difference forward modeling (e.g., zero-offset application).-Derivation of final velocity model for time-depth conversion.
The final result of the seismostratigraphic work allows an evident increase of effectiveness in hydrocarbon evaluation and production due to the detailed knowledge of lithofacies trends, lateral and vertical as well as estimates of the permeability distribution, possible local permeability barriers and sealing potential. The chronostratigraphic information content of seismic sequence analysis allows in addition for an improved wellto-well correlation. This remark is especially valid for 3D data and the resulting 3D stratigraphic model, which forms the basis for a reservoir model.
Geologic Modelling for Reservoir Simulation: Hanifa Reservoir, Berri Field, Saudi Arabia
Authors: Kompanik G. S. , Heil R. J. , Al-Shammari Z. A. , Al-Shammery M. J. 
Published: December 2007

ABSTRACT
A 3-D geologic model of the Hanifa reservoir was constructed using sequence stratigraphic principles and facies to control the distribution of porosity and permeability. The reservoir had been previously interpreted as having "layer cake" stratigraphy based on correlation of similar lithologies and similar appearing porosity inflections. The new geologic model incorporates a field-wide gamma ray correlation over 55 km from the non-reservoir rocks to the main producing area of the field. The gamma ray correlation produced a previously unrecognized reservoir geometry consisting of a high stand systems tract, a shelf (ramp) margin wedge, and a transgressive systems tract. This model represents our first 3-D geologic model based on sequence stratigraphy. This geologic model has been used successfully in reservoir simulation and field operations.
The reservoir consists of skeletal sands and stromatoporoid boundstone complexes to the north that grade to non-reservoir mudstones to the south. The reservoir was divided into 45 geologic layers. Core descriptions led to mapping facies distribution within each geologic layer. A 3-D lithofacies model was constructed and used as a template to calculate and assemble porosity and permeability models. A water-saturation model was also constructed based on facies specific J-functions. The geologic horizons were then grouped into 20 flow layers as the geologic front end into reservoir simulation.
The resulting geologic model has improved the Hanifa reservoir simulation by defining previously unrecognized reservoir geometries and providing the detailed resolution that enabled engineers and geologists to identify and understand the geologic attributes controlling fluid movement. The flood front has moved preferentially through grainstones in the highstand systems tract by crossing layer boundaries. Fluid flow has been impeded within layers that are dominated by bounds tones, wackestones or mudstones.
Upper Jurassic and Basal Cretaceous Outcrop Sequence Stratigraphy of Wadi Hagil, Ras Al Khaimah
Authors: Toland Christopher , Peebles R. G. , Walkden G. M. 
Published: December 2007

ABSTRACT
The Wadi Hagil succession represents a well exposed, easily accessible reference section for the Upper Jurassic and basal Cretaceous of eastern Arabia. Due to its ’offlap break’ (platform margin) position, this locality provides a detailed record of relative sea level change and yields vital clues to understanding the sequence stratigraphy of the adjacent platform.
The measured section in Wadi Hagil comprises three disconformity-bounded depositional sequences.
Sequence 1 (?Oxfordian) commences with an abrupt disconformable flooding surface overlain by 16m of hummocky cross-stratified cortoid packstones (transgressive systems tract) and 88m of peloidal packstones and grainstones (highstand systems tract).
The base of Sequence 2 is marked by a prominent erosional hiatus (?Kimmeridgian-earliest Berriasian) and an abrupt change in depositional environment from shoreface to platform slope (attributed to platform margin collapse during the Late Tithonian). Sequence 2 is of intra-Berriasian age and comprises a basal conglomerate (transgressive systems tract) upto 5.5m thick, overlain by 29.5m of clinostratified calpionellid lime mudstones (highstand systems tract).
The base of Sequence 3 (latest Berriasian-Early Valanginian) is marked by a spectacular ravinement surface with at least 40m of associated downcutting. This is interpreted as a Type I sequence boundary corresponding to the 128.5Ma boundary of Haq et al (1988). The sequence boundary is overlain by 46m of megabreccias representing a submarine canyon fill (lowstand systems tract) and more than 30.5m of radiolarian lime mudstones and calciturbidites (transgressive systems tract).
Innovative Approaches to Downhole Corrosion Control
Authors: Esaklul K. A. 
Published: December 2007

ABSTRACT
Corrosion control in oil & gas production has traditionally been accomplished through the use of corrosion inhibitors, coatings and materials selection.
Effective corrosion control is generally implemented in the design stage through rigorous evaluation of the anticipated operating conditions, and identifying the most cost effective and practical corrosion mitigation options. The process starts with application of predictive models, correlation to existing experience, and review of available technology; followed by laboratory testing under simulated field conditions.
This paper describes corrosion control philosophy, practices and innovative approaches applied to combat corrosion problems in operating fields. The approach shows how the dominating factors in corrosion of downhole tubulars are identified, and how predictive models are developed and applied to determine the extent of corrosion and predict tubing life. Success of sound corrosion mitigation relies on reliable and cost effective monitoring of corrosion. To that extent, new technologies are being implemented for the first time to monitor downhole corrosion. These new techniques are far superior to present techniques, and offer more reliable quantitative measurements than were previously attainable without pulling the tubing string.
Horizontal Well with Two Lateral Holes in Layered Limestone Reservoir: Performance and Test Interpretation
Authors: Mackay Alexander , Bustami S. S. , Jaber A. K. , Abdou M. K. 
Published: December 2007

ABSTRACT
Horizontal drilling was under consideration for the development of the poorer reservoir quality northern area of a large onshore oil field in Abu Dhabi. This paper presents the case history of two horizontal holes drilled in a pilot well to help evaluate horizontal well performance for development planning purposes.
Geological and petrophysical data are described. The reservoir consists of layered limestone with porous layers alternating with continuous, thin, dense, stylolitic intervals.
An existing vertical well, with production test history from two completion intervals, was re-entered. The short radius technique was used to drill two horizontal holes into two porous layers, separated by several intervening dense and porous intervals.
Production test results, before and after horizontal drilling, are presented. For both horizontal holes, productivity was higher than the previous vertical completions. Vertical interference testing was also carried out, by monitoring the pressure in the lower hole while producing from the upper hole. Well test interpretation is discussed. Results of analysis, assuming a single homogenous layer, are described. The layered nature of the reservoir appears to affect transient pressure behavior. Numerical simulation, with local grid refinement around the horizontal holes, was also used to match the test results, including the vertical interference test observed pressures.
Horizontal Drilling and Completion Fluids Design Criteria
Authors: Ezzat A. M. 
Published: December 2007

Abstract
The main objective of horizontal drilling is to place a drain-hole within the pay zone for a long distance to enhance productivity or injectivity. In Saudi Arabia, horizontal wells have been successfully drilled through reservoirs with different characteristics such as tight to highly permeable limestone, extremely porous and permeable dolomite and dolometic limestone, and highly permeable unconsolidated sandstone. Based on laboratory test data, non-damaging fresh water and salt-saturated/polymer systems were selected for drilling the carbonate pay zones and a special oil-based fluid was developed for drilling the sand reservoirs. These drilling fluids satisfied the same basic functions common to all drilling muds and provided excellent reservoir protection. Production rates of the completed wells have reached several fold higher than the vertical producing wells from these reservoirs without stimulation treatments. This paper presents the laboratory data generated and discusses the fluids formulations and design criteria.
Integration of Engineering Data and Geostatistics in Simulation of a Complex Carbonate Reservoir
Authors: Liu J. S. , Enwall R. E. , Davis R. R. , Douglas J. L. , Barber R. M. 
Published: December 2007

Abstract
Complicated geology and scarce data are the two major problems in simulation of the subject large carbonate reservoir. Sharp contrasts in permeabilities, ranging from tens to more than one million milli-darcy-feet, are observed in a few hundred meters radius of the reservoir. Field data and past experience in reservoir simulation indicate that the field performance is completely dominated by these super high permeability streaks. Recent studies have shown that these high permeability streaks are very localized. The occurrence of these streaks is random and not correlatable. Consequently, they may be only amenable to geostatistical techniques. The Indicator Conditioned Estimation (ICE) technique described in this paper is designed to honor the spatial structure inherent in the source data and to allow for the prediction of super permeability streaks in areas of no well data.
The use of pulsed neutron capture logging and production logging has been very successful in monitoring the sweep of the subject reservoir which is under a peripheral waterflood. At the same time, the logging data has also provided a wealth of information for the model construction; however, only the data derived from dry wells has been used in the past. A new procedure is developed to use information from wet as well as dry wells to augment the database for the model construction. This procedure in conjunction with ICE technique has formed an innovative way to generate the initial permeability distributions for a simulation model. It is expected that this initial permeability distribution should serve as a better starting point for the subsequent history matching process.