bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advances in Flotation Unit Design for Produced Water Treatment
Authors: Casaday A. L. 
Published: December 2007

ABSTRACT
Flotation units have been widely used for the treatment of produced water both onshore and offshore. They have, however, exhibited numerous operational and performance limitations. Over the past several years, new designs for the treatment of produced water by flotation have been developed. These have resulted from years of intensive research in both the laboratory and at oil production facilities. These new designs utilize features which improve the performance and reduce the operating problems associated with conventional designs.
The first design discussed is the pressurized IGF. This unit provides highly efficient removal of oil and suspended solids. It's operation improves safety because it eliminates any emission of volatile organic compounds, natural gas or hydrogen sulfide gas. The IGF resolves traditional flotation unit operating problems. These include the inability to operate under pressure, the production of large amounts of oily waste skimmings which require additional treatment, and the inability to operate on floating production facilities or tension leg platforms.
The recently developed and patented design includes several features which provide improved performance. These include the use of a cylindrical pressure vessel, the incorporation of floating skimmers for oil and suspended solids removal and a unique stator assembly for the dispersion of the gas into the liquid phase. Effluent from the IGF is suitable for discharge into surface waters or subsequent treatment prior to re-injection. The unit's design does not require motor driven skimmers. It's use can eliminate the need for additional pumps thereby decreasing the energy requirements of the water treatment equipment train.
A second new design which will be discussed is based on modification of an existing hydraulic induced gas flotation cell to operate as a dissolved gas flotation unit. The gas bubbles are formed by reducing the pressure of a gas saturated produced water stream. This produces a fine bubble dispersion which has been shown to remove smaller oil droplets than does conventional equipment. This patented process, called Hybrid Gas Flotation, allows for increased throughputs and improved effluent quality.
Production Analysis and Reservoir Simulation Identify Infill Drilling Potential in Previously Produced Basins
Authors: Syfan F. E. , Robinson B. M. 
Published: December 2007

ABSTRACT
Over the last several years, intensive reservoir studies were performed on the Davis formation (known locally as the Pregnant Shale) in the Fort Worth Basin, and the Travis Peak formation in the East Texas Basin. These studies were part of the Gas Research Institute's Tight Gas Sands Program designed to improve the overall understanding of hydraulic fracturing processes and production performance in tight gas sand reservoirs.
The reservoir studies consisted of production data analysis using analytical models and reservoir simulators. In addition, pre-fracture and post-fracture pressure buildup tests were analyzed using both conventional transient analysis techniques and reservoir simulators. This approach allowed us to evaluate various reservoir conditions ranging from simple single-phase, single-layer models to multiphase, three-dimensional models. As such, the analyses provided a more thorough description of the reservoir parameters that control well performance, one of which is the effective drainage area or recovery efficiency.
This paper summarizes the results of the reservoir studies conducted on the Davis formation and the Travis Peak formation and demonstrates the importance of proper reservoir characterization to maximize per well recovery and drainage pattern efficiency.
Inflow Performance Relationships With Inertial Effects in the Reservoir
Authors: Camacho-Velazquez Rodolfo , Padilla-Sixto Roberto , Vasquez-Cruz Mario 
Published: December 2007

ABSTRACT
This work presents results on inflow performance relationships (IPR) under the presence of inertial effects in the reservoir. Both, slightly compressible liquid flow and solution gas-drive systems are considered. Up to date, most of the studies on this area have been directed toward dry gas reservoirs. However, as it is shown in this paper, the presence of non-Darcy flow has a sound effect on inflow performance for reservoirs containing other fluids. Thus, the shape of the IPR curve for a liquid flow system may present a parabolic behavior, similar to the shape of the multiphase IPR curves.
For the case of multiphase flow it is illustrated that the value of the exponent "n" in Fetkovich's equation1, is smaller than one when non-Darcy flow effects are important. This observation agrees with Fetkovich1 conclusion based on field data. It is also verified that a cartesian plot, as suggested by Jones, Blount and Glaze2, is useful to detect and evaluate the presence of non-laminar flow.
The behavior of the integrand of the deliverability equation suggested by Fetkovich1 is explored under multiphase non-Darcy flow and a new deliverability equation is presented.
Synthetic examples obtained with a finite difference black-oil simulator are presented. The numerical model considers a variable bubblepoint formulation, which has important consequences under non-laminar flow, especially on the repressurization effects which influences the rate-pressure behavior. Also, field examples are presented.
Different procedures proposed in the literature to predict oil rates are examined under non-laminar flow conditions.
Stimulating Weak Formations Using New Hydraulic Fracturing and Sand Control Approaches
Authors: Abass H. H. , Wilson J. M. , Venditto J. J. , Voss R. E. 
Published: December 2007

ABSTRACT
This paper discusses particular aspects critical to designing a successful fracturing treatment for higher permeability reservoirs with the objectives of stimulation and/or sand control. The process entails creating a short and wide fracture and packing it with multiple layers of proppant, possibly incorporating a resin-coated proppant.
Use of a reservoir simulator to predict or history match a pressure drop profile throughout a given drainage area will be presented. A fracture length can be determined from the pressure drop profile so that a near wellbore damaged area is bypassed and formation failure conditions are not reached. Types of failure mechanisms responsible for solids production formation are discussed. Pressure analysis during fracture packing is presented.
A new technique to orient the perforations relative to the in-situ stress field for optimum fracturing treatment and sand control is presented. A comprehensive treatment design and operational recommendations are given. This paper includes the use of a three-dimensional fracture design model, proppant choice and scheduling, of carrier fluid and additives.
A New Method for the Relief of Annular Heat-Up Pressures
Authors: Leach C. P. , Adams A. J. 
Published: December 2007

ABSTRACT
Annulus fluid heat-up during production often causes high burst/collapse stresses, particularly in subsea wells where the annuli may be sealed. Various means have been tried to overcome the problem, but all suffer from problems of either high cost, potential unreliability or operational restrictions. This paper describes a new method for annular pressure relief, using a crushable foam wrap enclosing the top few joints of the inner string of the sealed annulus. The method is cheap, practical and effective in all cases.
Generalized Performance of Hydraulic Fractures With Complex Geometry Intersecting Horizontal Wells
Authors: Deimbacher F. X. , Economides M. J. , Jensen O. K. 
Published: December 2007

ABSTRACT
Hydraulic fracturing of horizontal wells is a relatively novel stimulation treatment. For most depths of petroleum interest fractures away from the well are vertical and normal to the minimum horizontal stress direction. If a horizontal well is drilled at a trajectory other than the expected fracture direction a complicated fracture-to-well connection is likely to occur. Past literature has suggested a longitudinal fracture initiation followed by a tortuous turning path towards the final fracture direction, or multiple fractures.
This phenomenon happens within a distance that is a few times the well diameter. The consequences are increased treatment pressures and a potentially severe fracture width reduction at the turning point. Posttreatment production performance is likely to be affected substantially. Reservoir simulation studies were carried out demonstrating the dependence of production rate on the angle between the horizontal well and the final fracture trajectory, the length of the perforated interval and the dimensionless fracture conductivity, under an assumption of a choke effect at the turning point. An angle threshold was identified beyond which the well production decreases significantly.
A New Method for Obtaining Injection Profiles and Fracture Apertures Using Radioactive Tracers
Authors: Reis J. C. 
Published: December 2007

ABSTRACT
A new method for interpreting radioactive tracer injection profiles has been developed for use after the tracer has entered the formation. Equations for obtaining fluid injection rates for radial flow and for obtaining in-situ fracture apertures for linear flow are presented. From a Monte Carlo study of gamma ray transport, it was found that the wellbore gamma ray intensity decayed exponentially with radioactive tracer distance into the formation. The attenuation of gamma rays reaching a centralized detector is independent of wellbore diameter. An equation for the dependence of the attenuation on formation bulk density and initial gamma ray energy was developed.
Steady and Unsteady-State Lifting Performance of Gas Wells Unloading Produced or Accumulated Liquids
Authors: Tek M.R. , Gould T.L. , Katz D.L. 
Published: December 2007

Abstract
Steady and unsteady state performance of wells subject to two-phase flow performance of wells subject to two-phase flow are considered. A new concept called "the lifting potential" is introduced. The concept explains stability phenomena observed in loading, unloading, heading and dying of gas wells. It is also shown to be a useful tool in designing well bore or gas lift equipment for optimum performance.
Introduction
Problems connected with design, engineering and performance analysis of wells subject to two-phase flow have been of continuing interest to the industry for some time. Oil wells producing volatile crude during primary producing volatile crude during primary recovery, majority of oil production during secondary recovery, condensate wells subject to retrograde phenomena in the well bore, and gas wells subject to marginal water production are typical of areas where multiphase flow problems are encountered.
In vertical two-phase flow systems the main problem of practical engineering import may be specifically stated as follows:
Knowing the geometry of conduit, physical properties of the two-phase flow physical properties of the two-phase flow system, and conditions prevailing at well head, predict pressure profiles down the flow string.
Contributions to various aspects of two-phase flow problems have been numerous in the literature.
Through the years a number of investigators choose to correlate both slippage and friction losses by a unique and single energy loss factor. Their efforts, now considered by many as first order engineering approximations, fell short of their desired goal because these correlations did not include the effects of all pertinent variables, and more importantly, they did not reflect the effect of various flow regimes.
Another school of thought is represented by other investigators who choose to define, measure and predict slip or "hold-up" as intermediate parameters leading to the calculations of pressure drops.
A Review of Well Injectivity Performance in Saudi Arabia's Ghawar Field Seawater Injection Program
Authors: Bayona H. J. 
Published: December 2007

ABSTRACT
In the late 1970’s, it became necessary to convert to seawater as the source of injection water in the pressure support program of the North Uthmaniyah section of the Ghawar Field in Saudi Arabia. This peripheral waterflood had been initiated by Saudi Aramco in 1966 to maximize recovery of oil from the Arab ’D’ limestone reservoir in this unique field, the largest in the world.
This paper will provide a brief introduction to the seawater processing facilities which includes over 400 kilometers of pipeline and can supply 4.2 MMBD of treated seawater.
The paper will also discuss Saudi Aramco efforts to study and mitigate declining well injectivities. Experience in water quality control, well stimulation efforts to improve injectivity, and analysis of well plugging characteristics/profiles and their relation to reservoir permeability will be covered. An empirical relationship between the injectivity index and the cumulative water injected has been published and is now being evaluated as a means of monitoring well plugging and, indirectly, to monitor water quality. Efforts made to minimize well plugging by improving seawater quality and by internally coating the seawater piping system are also discussed.
Finally, using solar powered flow computers to measure water injection rates and run pressure fall-off surveys will be compared to the previously used analog flow meters and subsurface pressure fall-off bombs.
Breathing New Life Into a Thin Oil Column by Horizontal Drilling
Authors: Al Zarafi Ahmed 
Published: December 2007

Abstract
The Shuaiba reservoir is one of a stacked system of reservoirs in the Saih Rawl field in Central Oman. Relative to other reservoirs in the field, development of the tight Shuaiba limestone has been unattractive because of rapid water breakthrough in vertical wells completed in the thin oil column.
The production performance of a trial horizontal well, drilled in 1991, has been very encouraging. A three-fold increase in oil productivity has been observed, indicating that encroachment of water to horizontal wells is significantly less of a problem than coning to vertical wells. Simulation models have been constructed and used to history match the performance of vertical wells and predict the performance of full field development by horizontal drilling. Optimum well spacing has been identified for various values of oil column height while sensitivities to other identified key variables, such as reservoir quality have been evaluated.
The ultimate recovery from the Saih Rawl Shuaiba reservoir can be significantly increased via development by horizontal drilling, at an appreciably lower unit cost than development with vertical wells, thus confirming the potential for a sizeable development project.
Seismic Modeling Study of Subsalt-Imaging Problems in the Gulf of Suez
Authors: Ruckgaber G. M. 
Published: December 2007

Abstract
Seismic waves used to image pre-Miocene reservoirs in the Gulf of Suez are often severely hampered by distortion and noise that arise in the shallower South Gharib Salt and Zeit formations, respectively. A sequence of seismic forward models was computed for a structure in the B-Trend area of the southern Gulf to isolate the causes of this distortion and noise and investigate their significance for seismic imaging.
Processing and analysis of the resulting model data indicate that current seismic processing methods followed by depth migration can adequately image pre-Miocene structure in the B-Trend and, hence, in most of the Gulf of Suez. Seismic energy traversing the thin, cyclic layers of the Zeit formation experiences frequency-dependent delay, but low-pass filtering minimizes the dispersive effect of this frequency-dependent delay and yields a seismic wavelet only negligibly attenuated.
The major problem for seismic imaging is caused by long-period multiples between the air-water interface and the many high-reflectivity interfaces of the Zeit. These multiples are poorly attenuated by CMP stacking-particularly at the bottoms of synclines flanking the salt swells. The resulting high-amplitude events are smeared laterally upward by migration, severely masking images of structure beneath the adjacent salt swells.
Application of Reprocessed Seismic Sections from Petroleum Exploration Surveys for Groundwater Studies, Eastern Abu Dhabi, UAE
Authors: Woodward D. G. , Al-Jeelani A. H. 
Published: December 2007

Abstract
Field tapes from a deep seismic survey for petroleum exploration were reprocessed in order to extract seismic information on shallow reflectors for use in ground-water exploration. A potable aquifer in eastern Abu Dhabi occurs at depths less than 150 m. Field methods, acquisition parameters, and section processing were originally designed to enhance reflectors expected at depths up to 6,000 m. Seismic data collected from depths of about 110-330 m were muted from the original sections, so that all seismic data concerning the aquifer were deleted from these sections. Reprocessing efforts concentrated on restoring information for the first second of seismic data.
A unique sequence of reprocessing parameters was established based on results from many experimental trials. Major enhancements to the resolution of shallow reflectors resulted from: (1) application of a 20-hertz, low-cut filter; (2) recomputation of static corrections to a datum nearer the land surface; (3) intensive velocity analyses; and (4) near-trace muting analyses. The number, resolution, and continuity of shallow reflectors were greatly enhanced on the reprocessed sections, as was the delineation of major faults and folds. The 33 reprocessed sections were instrumental in preparing a map of the major structural features which affect the shallow aquifer system.
Results from this study show that seismic field tapes collected for deep petroleum exploration can also be reprocessed to explore for shallow ground water.
Hole Stability in Nile Delta Area: Abu Madi, Nidoco, and El-Qara Wells
Authors: Hussein N. K. , Taha A. L. A. E. 
Published: December 2007

Abstract
Hole instability in Nile Delta area, specially in the Middle and East leases is one of the main drilling problems encountered in most of the wells drilled either by Petrobel or Nidoco. Shale swelling, caving, tight holes, and consequently loss of circulation problems were experienced and overcame using several techniques.
This paper is focused on the analysis of the main drilling hazards related to shale instability including analysis of pore pressure data obtained from sonic, sigma, and RFT logs and prediction of pore pressure expected in the forecasted wells.
It discusses the different mechanisms of Nile Delta shale instability, Field observations and results of X-Ray diffraction analysis of shale samples collected from the area wells led to a significant improvement in shale stability by using potassium polymer mud instead of sodium chloride lignosulphonate mud. Also tight hole and differential pipe sticking possibilities while drilling through low pressure porous sands were reduced by using ultra fine cellulosic materials.
Conclusion and recommendations for drilling performance optimization are included in this paper.
Solar-Powered Air Compressor: An Economical and Ecological Power Source for Remote Locations
Authors: Soules T. R. , Tran P. V. 
Published: December 2007

ABSTRACT
Many, wellheads that require safety systems are located in remote areas where conventional power sources are not available. These safety systems require power in the form of hydraulic or pneumatic pressure to operate various sensors and wellhead equipment. Until now, remote locations have been limited to three sources of power: (1) bottled nitrogen, (2) Diesel/gasoline-powered systems, and (3) the use of gas off the well. Now, however, there is another option.
A state-of-the-art, solar-powered air compressor has been developed that has the capability to provide the required power for the safety systems located in remote locations.
In addition to offering an economical and ecological solution to the need for a safe and reliable power source, the solar-powered air compressor can provide a more cost-efficient option to the above alternatives. The solar-powered air compressor is inexpensive to maintain since primary service (battery replacement) is only necessary every 2 to 5 years, and the units can be transported easily as they are designed on 4-foot [1.22 meter] skids that fit into a standard pick-up truck.
This paper will describe the operating principles and design considerations which led to the development of a new solar-powered system, four of which are currently in use in Gabon.
Modified SSSV for Oil Wells With Sanding Tendency
Authors: Gazaq N. M. , Hedjazi A -K. G. , Hilts R. L. 
Published: December 2007

ABSTRACT
Many of Saudi Aramco’s wells have been experiencing a substantial increase in sand production resulting from increased drawdown and water production. As a result, sand has accumulated in the internal mechanism of many subsurface safety valves, rendering the valve’s internal mechanism inoperative.
A design change that was proposed by the manufacturer to eliminate the possibility of sand accumulation in the valves was approved by Saudi Aramco for installation on a trial basis. The design modification incorporated technology typically used in tubing retrievable subsurface safety valves.
The modified valves were installed and tested in sand-producing wells. Based on field results, other valves have been modified and installed. Their performance and ability to maintain the safety control required is presently being monitored, and the results to date have been encouraging.
Will Parallel Computing Ever Be Practical?
Authors: Killough John E. 
Published: December 2007

ABSTRACT
Recently the lure of scalable distributed memory parallel computing with hundreds or even thousands of inexpensive, but powerful, RISC-based processors has resulted in a significant effort in the development of software for petroleum engineering and seismic applications. Unfortunately, few if any applications have found their way into a production environment from the reservoir engineering perspective. Several hurdles remain to be overcome if parallel computing is to become commonplace as a tool for applications. This article addresses three areas of concern for a major area of petroleum engineering - reservoir simulation: load balancing, data structures, and linear equation solutions. Examples from real reservoir simulations and possible solutions for several situations are discussed.
Evaluation of Pipeline Integrity by On-Line Inspection
Authors: Heraiba F. A. 
Published: December 2007

ABSTRACT
Advanced On-line inspection tools coupled with reliable interpretation of inspection data and adequate reporting formats are required to evaluate the structural integrity of the pipeline. This evaluation is a vital requirement for pipeline operators in order to define necessary preventive measures and repairs required to avoid line rupture or leakage.
ZADCQ is operating a large pipeline network transferring crude oil, gas and injection water under a wide range of operating conditions.
In order to evaluate the integrity of this network, ZADCO had conducted several surveys using different types of inspection tools.
This paper presents an operator's point of view about the capabilities and limitations of the different tools and the reporting formats submitted from inspection contractors.
The paper provides recommendation about methodology for selecting the most appropriate tool for a specific job.