bluuebunny/crossref_metadata_2025 huggingface dataset:
Permian Khuff in Abu Dhabi: Geological Re-Evaluation Using Well Logs, Cores, Testing, and Seismic Data
Authors: Loutfi G. , Hamd M. Abul
Published: December 2007

The Permian Khuff Formation in Abu Dhabi has been the subject of a thorough re-evaluation of all available data to ensure that the gas resources of this major reservoir sequence are well defined and optimumly exploited. The Khuff is one of the most complex carbonate reservoirs in the Middle East, with vertical variations in lithology, pore volume and types, and fluid content. Over the years there has been major changes in the technology used and, thus, also in the quality of the data acquired - some of which were obtained more than ten years ago.

The complex Khuff pore systems and the initial estimates of their producibility are defined by a thorough integration of core and log data. The most detailed analysis was performed using cores, but as this data is not available for many producing zones it was necessary to employ other data. A combined geological and petrophysical data base allowed interpretation modelling of log data, for zones which were not cored. No unique porosity/permeability relationship can be defined for the Khuff reservoir zones as they vary in character, so a data base approach was used to determine the permeability in each of the Khuff wells investigated in this study. A significant improvement in the saturation and calculation of matrix permeability was made by realistically defining Archie's "m" exponent - especially in zones with secondary porosity.

Fractures play an important role in determining the permeability of the Khuff reservoirs. The evaluation of fractures was carried out by integrating logs, borehole imagery, core data, pressure tests and well tests. Most of the highly fractured intervals are within the low porosity dolomite zones which were not completely cored. Calcitic and/or anhydritic zones had poorer reservoir fractures because fewer fractures were developed and because of the pervasive cementation of fractures by anhydrite in anhydritic zones.

Seismo-stratigraphic re-evaluation was initiated to determine seismic criteria of the Permian Khuff reservoirs, and ultimately, to document seismic signature (finger prints) for the Khuff Gas Zones. A fully integrated study, comprising interpreted open hole logs. Check Shots Surveys, Synthetic Seismograms, production data and seismic sections was conducted. Results were encouraging. Further investigations are however, required.

This multidisciplinary study has advanced the understanding of the Khuff reservoir zones in Abu Dhabi and has improved the evaluation approach for new wells.
Optimized Completion Significantly Reduced Cost and Time in Gulf of Suez Fields
Authors: Mansour S. , Khalaf F.
Published: December 2007

This paper presents the chronological development of Gulf of Suez Petroleum Co. (GUPCO) offshore well completions. Reservoir depletion and the problems experienced with the initial completions prompted the need for basic changes. Several changes in completion systems were studied before an optimum solution was selected. The development includes all the areas of original completions that had shown operational shortcomings: the completion-fluids design and selection, down hole equipment, running and pulling operations, wireline phase, perforating, and initial flow phase. All the changes interacted and resulted in the completion optimization which have considerably reduced operations time and cost, significantly reduced operational problems, and increased well productivity. It worth to note that, as a result of completion optimization, now a completion job takes less than one half of the time that was spent to complete one well ten years ago.
Resolution of Fault Block Communication Leading to an Optimal Plan of Depletion, Abu Gharadig Gas Field, Egypt
Authors: Lachance D. P. , Rezk A. S.
Published: December 2007

This paper describes the successful determination of the existence and degree of communication between gas reservoirs in adjacent structural fault blocks in a field in western Egypt. The method used was the comparison of volumetrically determined gas in place with material balance determined gas in place. Individual well performance data were merged to show the existence of pressure communication between wells and between fault blocks.
3-D Seismic Data Analysis of Late Cretaceous and Tertiary Velocity Anomalies in Northeastern Saudi Arabia
Authors: Snell G. W. , Airey J. T.
Published: December 2007

Velocity anomalies attributed to Late Cretaceous and Tertiary solution collapses have hindered the exploration for low-relief structures in Northeastern Saudi Arabia. Complex time distortion in key seismic horizons is often associated with collapse features and accompanying fracturing and secondary mineralization. It is often difficult to distinguish real low-relief structure from velocity-induced anomalies with conventional 2-D seismic control, which provides united subsurface coverage. A 3-D seismic survey was acquired near Kurayn Island in an attempt to develop seismic processing and interpretation criteria to resolve velocity-induced time anomalies. Previous seismic work showed this area contained numerous solution collapse features.

The dense subsurface coverage provided by 3-D seismic data exposed the high spatial frequency and complexities associated with collapse features. Parameters determined by analyzing spatial and time relationships of collapse features in this area can be applied to resolving similar problems throughout the region.
Preliminary Investigations Into Possible Stratigraphic Traps, Offshore Abu Dhabi
Authors: Azer S. R.
Published: December 2007

During the last three decades, exploration efforts in offshore Abu Dhabi were mainly focused on the search for the more common (in the Arabian Gulf) conventional type structural trap. The existence of stratigraphic traps in offshore Abu Dhabi is possible and the deliberate exploration for those more difficult subtle traps is demanding.

So far in offshore Abu Dhabi, the Mishrif is the only formation which was given special attention for possible stratigraphic traps.

The main objective of this paper is to highlight the possibility of stratigraphic traps in formations other than the Mishrif. It is not meant to delineate or pin point locations of certain stratigraphic traps, but to put things in perspective regarding these traps. The approach is to establish general models of stratigraphic plays of different kinds in various reservoirs, which could be applied to offshore Abu Dhabi. These models are a starting point and would be pursued in greater detail at a later stage in collaboration with seismic modelling.

Examples from the Lower Cretaceous Thamama, and Jurassic Arab, Diyab and Araej formations are considered.

The traps most likely to occur in offshore Abu Dhabi are mainly updip porosity pinchouts, diagenetic and unconformity traps.
Geological Model and Reservoir Evaluation of the Lower Cretaceous Bab Member in the Zakum Field, Abu Dhabi, U.A.E.
Authors: Aldabal M. A. , Alsharhan A. S.
Published: December 2007

In the Zakum Field, the Shuaiba Formation (Aptian) is the upper most rock unit of the Lower Cretaceous Thamama Group, in ascending order it is divided into three zones, Thamama IA, IB and IC. The last two have been termed the Bab Member, has an average thickness of about 230 ft. and shows a diverse lithology. Minor changes in eustatic sea level at the time of deposition produced a major change in the lithofacies distribution across the field. These range from deep water basinal to shallow shelf sediments.

The lower part of the Bab Member (Thamama IB) is divided into three: A progradational carbonate cycle of deep water argillaceous globigirinal limestone at the base (Tar Unit), which could represent a good source rock. Above it are drowned shelf sediments of bioclastic wackestone with a moderately developed reservoir facies (IX unit). These end with a highly dolomitized unit of poorly developed reservoir facies, which forms a comparatively good seal.

The upper part of the Bab Member (Thamama IC) consists of calcareous shale interbedded with limestone of good reservoir quality. The limestone is separated into two reservoir facies units (IT & IW) and is well developed in the East, representing a shallow shelf to high energy shoal deposits (oolitic grainstone, calcareous algae, orbitolinid and skeletal debris). These sediments were transported westward and deposited over the slope of the deeper water environment and limiting the reservoir facies to the crest and eastern flank of the field.

In order to evaluate the economic potential of the sequence, all of the possible reservoir units were defined using wireline logs and petrographic description.

Facies units (IT, IW & IX) were mapped over the field. Units IT & IW represent a stratigraphic trap, with some later influence of structural uplift due to deep seated salt piercement. The oil accumulation in the reservoir units is restricted to the shelf and shelf edge facies. The tilted oil/water contact (OWC) is a pronounced feature of the field.

The prolific cyclic carbonate sand facies (IT & IW) as part of abroad carbonate shelf platform extend further East of Zakum Field. Subsequently, development of reservoir quality connot a potential future prospect.
Oil Prospectivity of the Khuff Formation in Oman
Authors: Abu-Risheh A. , Al-Hinai K. B. M.
Published: December 2007

The Khuff formation has been known to contain gas bearing reservoirs in several fields in the Gulf states. With the discovery of oil in this formation in the Yibal field in 1986, the Khuff carbonates have been given increasing attention and became a significant target for oil exploration in Oman.

While a number of the sedimentological and geochemical aspects of the Khuff have yet to be analysed, the earlier model of a generally uniform depositional sequence is still being regarded as correct.

The oil prospectivity of the Khuff reservoirs lies in the various elements of its deposition, diagenesis, burial depth and the geometric relationships between this formation and underlying sources of hydrocarbons. The basal and pre-Khuff erosional or nondepositional unconformities may have played a significant role in charging the reservoirs.
Generation, Migration, and Transportation of Gas-Contaminated Regions of Drilling Fluid
Authors: Casariego V. , Bourgoyne A. T.
Published: December 2007

This paper presents a new method to predict both gas velocity and gas concentration for processes of well control operations in vertical or near vertical wells. The effect of gas concentration on gas velocity is taken into account. The dispersion of the gas-contaminated region of drilling fluid with time can be determined for both static and circulating well conditions.

The method was integrated into an existing well control simulator computer program. The improved numerical model closely predicted measured casing pressure profiles that were obtained in a 6000-ft research well.
The Optimization of the Red Oak Infill Drilling Program in the Arkoma basin
Authors: Flournoy C. M.
Published: December 2007

Amoco Production Company has drilled 47 wells in the Red Oak Field since the fall of 1985. During this time, average drilling times and well costs have been reduced approximately 45 percent through the optimization of both air and mud drilling practices, a streamlining of casing programs, and an increased ability to avoid downhole problems. The keys to the optimization process have been extensive post-appraisals of offset wells and thorough planning of each upcoming well, coupled with aggressive wellsite supervision during the drilling process. The result has been a fairly simple drilling plan with emphasis on the consistent execution of basic drilling practices.
A Case History: Inhibitive Drilling Fluid System and Large Cutter PDC Bit Usage Reduce Overall Well Cost and Drilling Days
Authors: Allen M. K. , Wampler C. W.
Published: December 2007

The utilization of an inhibitive mud system coupled with the use of Large Cutter Polycrystalline Diamond Compact (PDC) bits reduced overall well costs by 47.6% and similarly reduced drilling days by 57.7% when compared to the seven previous wells drilled from the same platform. This trouble-free well was drilled in Block 557, West Cameron, Louisiana and shows the benefit of proper drilling fluid and bit selection.

The design of the drilling fluid was predicated on the use of a partially hydrolyzed Polyacrylamide (PHPA) functioning as a protective colloid. The PHPA reduces the surface reaction of the drill cuttings which limits their hydration and dispersion. This drilling fluid system, combined with the optimization of hydraulics, eliminated bit balling and provided a stable wellbore while drilling highly reactive gumbo. As a result, the Large Cutter PDC bit selected was able to drill in the proper shearing mode and penetration rates were maximized.

The West Cameron area is categorized as a difficult location in which to drill due to the extremely reactive shales encountered. The frequency of stuck pipe that occurred on the previous wells was eliminated and was attributed to the thin, compressible filter cake and excellent hole cleaning provided by the PHPA drilling fluid. Study of the filter cake compressibility ratio at the drilling site was used to monitor cake quality.

Comparison of the over-all well costs, drilling days, rotating hours, and number of bits used on the subject well versus the seven offsets defines a "learning curve" which should be considered when drilling future wells.
Extensional Viscosity Effects in EOR
Authors: Jones D. M. , Walters K.
Published: December 2007

Evidence is first advanced that some polymeric displacement fluids of potential use in EOR experience abnormally high resistance in extensional flows. Since flow through a porous medium involves a substantial extensional flow component, it may be argued that there is justification for studying the effect of this high extensional-viscosity behaviour in a number of idealized geometries of relevance to EOR conditions. The resulting experiments indicate that, at low flow rates, shear viscosity is the dominant influence, but that, after a critical set of conditions are attained, extensional-viscosity considerations become all-important and the observed pressure losses are against any expectation based on conventional fluid mechanics. The relevance of these critical conditions, after scaledown, to practical porous medium flow is under active consideration.

Flow visualization studies support the pressure drop measurements in emphasising the strong influence of high extensional viscosities in flows through tortuous geometries.
Evaluation of Volumetric Conformance for Fenn-Big Valley Horizontal Hydrocarbon Miscible Flood
Authors: Asgarpour S. S. , Todd M. R.
Published: December 2007

Many experimental and mathematical studies of volumetric conformance in a miscible flood have been presented in the literature. However, little attention has been paid so far to the field evaluation of volumetric conformance.

In the Fenn-Big Valley hydrocarbon tertiary flood, several techniques and a simulation study have been used to evaluate volumetric conformance. Nine water and gas tracers were injected early in the life of the tertiary flood to trace the movement of both injected water and solvent. The results of the tracer tests along with Bi-weekly compositional analyses of produced fluids and field measurement of viscosity provided valuable information.

A reservoir simulation study served as a tool to describe the interaction of the miscible flood process and the reservoir geology. The historical performance of the primary natural water drive and the first five years of solvent injection were reproduced with a fair degree of accuracy by a simulation model of one pattern element within the project area. The miscible flood description which resulted in the best fit of the observed pattern flood performance depicts a displacement that is characterized by modest viscous instabilities and gravity override.
Examination of BHTV, FMS, and SHDT Images in Very Thinly Bedded Sands and Shales
Authors: Hackbarth C. J. , Tepper B. J.
Published: December 2007

Three logging tools can produce detailed images of the wellbore wall, based upon variations in rock properties: the Borehole Televiewer (BHTV), an acoustic device, and the Schlumberger Stratigraphie High-Resolution Dipmeter (SHDT) and Formation MicroScanner (FMS), electrical tools that measure relative formation resistivity.

A Shell well was cored and then logged with the BHTV, SHDT, and FMS tools. The rocks consist, in part, of thinly interbedded sands and shales, with bed thicknesses down to 1 mm thick.

The log and core data from this well were rigorously compared to the images generated by the BHTV, SHDT, and FMS tools. We conclude that the BHTV, SHDT, and FMS produced good images of the interbedded sands and shales down to a bed thickness of about 1.5 inches [38 mm]. Below 1.5 inches [38 mm], the SHDT image showed closer to the true number of very thin beds present. Overall, the BHTV amplitude data gave the best sense of actual sand:shale ratio; the FMS images were slightly less similar to the core, compared to the BHTV and SHDT. All three tools are influenced by very small changes in borehole size. Heavily cemented zones are easily detected by all three tools. None of the three tools produced an accurate image of slumped silty shale or homogenous-looking silty shale, possibly due to irregular borehole washouts.
The Benefits and Application of Rapid Mineral Analysis Provided by Fourier Transform Infrared Spectroscopy
Authors: Harville D. G. , Freeman D. L.
Published: December 2007

Quantitative mineralogical information is critical to the characterization and exploitation of hydrogarbon reservoirs. Fourier transform infrared (FTIR) spectroscopy can now routinely provide this information. The instrumentation used to perform FTIR spectroscopy does not require ionizing radiation or special utilities, making the instrument more versatile. Using a computer to interpret the raw data removes the subjectivity prevalent in other techniques. The major advantages of FTIR over other analytical methods are that it is rapid (5 to 6 samples per hour) and cost effective. Furthermore, FTIR can be performed on a minimal amount of sample. Typical samples such as drill cuttings, trimmed ends of core plugs, and sidewall core samples are suitable.

FTIR is a valuable mineral analysis technique, whether used by itself, or in conjunction with other investigative methods. Specifically, its rapid nature lends itself to many different applications. Rapid, quantitative mineralogy may be used to calculate matrix density, yielding more reliable porosity calculations from compensated density logs. Correction of Vsh from gamma-ray logs can be done using the total clay and potassium feldspar content given by an FTIR analysis. In some areas, a timely mineral analysis may identify low resistivity "pay zones" in clay rich areas. Rapid mineral determination can be useful in quickly determining formation breaks or marker beds, and delineating zones of cementation. This type of information also provides an important first step in formation evaluation. Mineral composition, coupled with scanning electron microscopy, may identify fluid-sensitive minerals and potential production problems. Examples of such applications as described above are given in this paper.
Cement Bond Logs of Fiberglass Casing
Authors: Maki V. E. , Hamilton L.
Published: December 2007

In the present article, we address the use of a specially configured Pulse Echo Tool (PET*) to evaluate cement bond logging in fiberglass casings. A preliminary mathematical model of the tool response showed an echo pattern in free pipe markedly different from that in well bonded casing. This led to a series of laboratory and field experiments to confirm the modeling results. In the field test waveforms, the reflections from the inner and outer surfaces of the fiberglass, as well as the cement to formation (water) reflections, are quite clear and consistent with the predicted amplitudes and polarities.

Long duration waveforms were recorded and displayed in a seismic type format. The waveforms show the extent of the cement sheath around the casing, and the signals from the fiberglass to cement interface. This information helps evaluate the cement bond to the formation.

A signal processing algorithm utilizing the Hilbert transform of the data was developed to eliminate the tedious, time consuming manual analysis of the waveforms. The mathematics are used to derive the amplitude and phase of the reflection from the outside of the casing. This procedure allows the generation of the logs of the fiberglass to cement interface in the field in real time.
Determining a Reliable Estimate of the Geothermal Gradient from Shut-In Temperature Recordings
Authors: Carlson N. R. , Barnette J. C.
Published: December 2007

The interpretation of temperature logs from a production or injection well often is aided by knowledge of the geothermal gradient, i.e., the natural variation of downhole temperature with depth, prior to disturbing the profile with such operations as drilling, producing, or injecting. In a temperature survey temperature profiles are recorded with the well dynamic (on production or injection) and these frequently are accompanied by profiles measured with the well shut-in. During shut-in, the temperature at any depth in a well gradually recovers toward the natural, or geothermal, value.

As an aid to interpreting the dynamic profile, attempts occasionally are made to estimate the geothermal temperature at a given depth from a knowledge of the temperature behavior at that depth during shut-in. Equations and methods are presented for estimating the geothermal temperature at a particular depth, based on dynamic and shut-in temperature values, m addition, techniques are shown for determining the reliability of the estimated geothermal temperature. These techniques suggest guidelines as to when the shut-in profiles should be recorded, in order to enhance the reliability of the estimated geothermal value.
Relationships Between Formation Strength, Drilling Strength, and Electric Log Properties
Authors: Onyia E. C.
Published: December 2007

The in-situ mechanical strengths of rocks are very difficult properties to determine or measure because of variation in stress states and rock anisotropics. On the other hand, drilling penetration rates in rocks which are related to some rock strengths can be measured with a higher degree of reliability in the field. From penetration rate and other drilling data, a rock's drilling strength may be determined and related to its mechanical properties.

Wireline electrical log data have been extensively used in reservoir characterization and sometimes give direct measurements of some elastic properties of the rocks. However, there is still the need to evolve some universally acceptable rock strength determination method from wireline electric log data. This approach has the advantage of not requiring extensive drilling and laboratory data and also provides a realistic estimate of in-situ rock strength.

This paper discusses relationships between rock drilling strength and some wireline log properties and shows how a formation's drilling strength can be estimated from log data.
OPUS: An Expert Advisor for Artificial Lift
Authors: Valentin E. P. , Hoffmann F. C.
Published: December 2007

In many cases of oil production, it becomes necessary to activate wells by a bottomhole pump to maintain sufficient flowrates to guarantee the profitability of production. A careful selection must be made among different processes, because the poor choice of an activation system could result in problems of reliability or inefficiency, leading to excessive operating costs.

The OPUS (Optimal Pumping Unit Search) system, by enabling a rational approach to various aspects of process selection, helps the oil producer to find the processes best suited to the field case considered.

On the one hand, OPUS integrates an expert system that synthesizes all the knowledge acquired on different systems such as sucker-rod pumps or progressive cavity pumps, hydraulic piston or jet pumps, submersible electric pumps or gas-lift. This knowledge base is used by an inference engine to make an optimum choice after analyzing all the technical and economic criteria. On the other hand, OPUS controls the use of technical sizing programs that support two-phase flows, and economic programs that estimate the unit cost per barrel produced with the aid of the processes chosen.

This system is now in its industrial operational phase and is successfully being used in various projects proving its qualities of flexibility and rapidity.
Field Determination of Fracturing Parameters for Overpressure Calibrated Design of Hydraulic Fracturing
Authors: Shlyapobersky J. , Walhaug W. W. , Sheffield R. E. , Huckabee P. T.
Published: December 2007

This paper proposes modifications to test procedures, currently in use in the industry, and presents techniques for design and analysis of hydraulic fracture tests. The proposed approach is used for an accurate determination of the fracture overpressure and the total leak-off coefficient which are necessary for the overpressure calibrated design of hydraulic fracture stimulations.

The unified approach of performing and analyzing micro and minifrac tests increases the accuracy and reliability of test results. The test procedures account for the real in-situ conditions of the borehole, formation, and the created fracture. The test performance and data analysis are an on-site interactive process that quantifies these in-situ conditions and optimizes accordingly the controlling test parameters, such as the flow rate and pumped volume. The calculations used in the on-site design and analysis of hydraulic fracture tests can be programmed on a hand-held calculator.

A brief discussion of the conventional micro and minifrac tests is presented. Limitations of this conventional approach are identified and illustrated by two examples. The requirements for an accurate determination of the minimum in-situ stress are formulated and modified test procedures which satisfy these requirements are proposed. The theory and procedures for the design and the interpretation of hydraulic fracture tests, uniformly used for both micro and minifrac tests, are outlined. Two field examples demonstrates the presented theory and test procedures.
Rheological and Physical Differences Between Foam and Emulsion Fracturing Fluids
Authors: Blauer R. E. , Phillips A. M. , Craig D. P.
Published: December 2007

The mechanisms responsible for desirable rheological and physical properties of fracturing foams and emulsions are essentially identical for both types of fluids. Laboratory data shows the conversion from emulsion to foam for certain combinations of water and a volatile discontinuous phase causes no appreciable change in rheological properties of the fluid.
Oil/Water Flow Structure Measurements in Inclined Pipes
Authors: Vigneaux P. G. , Catala G. N. , Hulin J. P.
Published: December 2007

Oil-water flow structures are mapped in 10 cm and 20 cm ID pipes at deviation angles between 5° and 65°. The slip velocity Vs between oil and water is independent of the flow-rate Qt and generally lower in the smaller pipe. At low oil fractions all the oil gathers at the upper side of the pipe. At medium fractions, the radial water fraction gradient is constant with Qt and the water content: Vs is related to the velocity of internal gravity waves due to the mixture density gradient. The relation between these features and the response of production logging tools is discussed.
Crude Oil/Natural Gas/Water Three-Phase Flowmeter
Authors: Chen Xuejun , Chen Lixun , Zhou Fangde , Lin Feng
Published: December 2007

The individual flowrates of crude oil, natural gas and water three-phase mixture are measured separately by using a single flowmeter. The measuring principle is the combination of a cross-correlation method with multi-parameter measuring technique. The cross-correlation method is used to measure the overall flowrate of a three-phase fluid mixture. A bypass pipe is used to separate the liquid fluid from the three-phase mixture by adjusting the pressure drop of main flow pipe and to measure the oil volume fraction in the remaining oil-water mixture. The volume fraction of natural gas in three-phase fluid is measured from the main flow. The data collection and the cross-correlation are done with an IBM personal computer. The flowmeter is compact and non-invasive. The experiments have been done in the laboratory and in the field. The flowrate range measured is more extended than that of single phase flowmeters, such as a turbometer or orifice plate. The measuring error is about 5 percent.

This kind of three-phase flowmeter is suitable in many kinds of oil wells to measure the flowrates of crude oil, natural gas and water, including-flows with high water to oil ratios or high gas to oil ratios. The cost of a three-phase flowmeter is lower, so that it is possible to install a flowmeter in each oil-well.
Diverless Connection of Flexible Lines to Subsea Trees Offshore Brazil
Authors: Chaperon G.
Published: December 2007

The water depth at which subsea satellite wells have been completed and connected in the Campos field, offshore Brazil, has increased from 1 000 ft [300 m] to 1 600 ft [490 m] in the last three years. Plans are now being prepared to produce such wells in water depths up to 3 300 ft [1 000 m] within another three years.

These projects have required that procedures and equipment be devised to allow the connection of production flowlines and control umbilicals in areas well beyond the current diving capability of just over 1 150 ft [350 m] for normal operations.

Coflexip, as a contractor to Petrobras, has participated in the engineering, manufacturing and installation efforts which resulted in the successful use of two primary diverless connection methods: Horizontal subsea pull-in / lay-away,Surface connection / tree-flowlines simultaneous lay down / lay-away.

This paper describes the two concepts, and presents installation sequences for both methods. Engineering, equipment and installation interfaces are discussed. Specifically, the coordination of tasks between the operator and its vendors and installation contractors is shown to be essential to the successful and timely execution of the operation.

As a conclusion, the paper evaluates and compares the merits and limitations of both methods, and explains why the later is presently gaining favor as the installation water depth increases at the Campos field.
Innovative Technology in Producing Operations
Authors: Hearn D. D. , Blount C. G. , Hightower C. M. , Coleman D. R. , Carlberg B. L. , Wolf N. O. , Clayton C. K. , Blevins B. A. , Turner J. M. , Knight R. M. , Nethers J. , Eatwell W. D. , Craig D. R. , McClintock P. , Krause L. , Andrew J. H. , Hall J. W. , Hamouda A. A.
Published: December 2007

The Innovative Technology in Producing Operations Forum is designed to allow the discussion of and dissemination of information about technical innovations and solutions in production engineering that are of immediate practical use but do not warrant a full-scale paper. Each subject is presented in a five to eight minute period with a discussion period of seven to ten minutes. A wide range of subjects is encompassed in the session. Abstracts of the presentations follow.
A Field Development Program in Hydraulic Fracture Stimulation
Authors: Saucier R. J.
Published: December 2007

The Fracture Development program was defined and implemented by an operating division of what is now Shell Western E&P Inc (SWEPI) in 1982. The objective of this program has been to improve hydraulic fractured well productivity through an increased understanding of hydraulic fracture behavior and improved design and optimization techniques. Program accomplishments reflect an effective cooperative effort between SWEPI, Shell Development Company, and Service Company personnel.

Major developments include those of the AWP Olmos and McAllen Ranch field areas. In AWP, frac height was defined and both design height and length were increased through developments by factors of 2 over original estimates. Additionally, fracture fluid type was changed from oil to water based fluids, minifrac testing was initiated, field quality control (Q.C.) procedures were instituted, proppant type was changed and proppant concentrations reached then unprecedented levels of 15 lbm/gal [1797 kg/m3] while costs were reduced. In McAllen Ranch, fracture height growth was studied, minifrac testing was initiated, detailed Q.C. procedures were instituted, proppant concentrations were increased to over 2 times previously set limits, and fracture quality improved while costs were reduced.

The benefits of this Fracture Development Program have been improved well performance, increased technical capabilities, enhanced R&D model development, and improved service company products and service.
State-of-the-Art Fracture Stimulation of the Upper Morrow Formation in the Anadarko Basin
Authors: Northcutt J. C. , Robertson C. J. , Hannah R. R.
Published: December 2007

Field application of a state-of-the-art fracture stimulation technique has been used to achieve higher proppant concentrations than generally pumped by industry in the Upper Morrow formation of the western Anadarko Basin. As a result of the application of this technique, greater production increases have been realized.
A Comprehensive Theoretical Treatment of Fracturing Fluid Loss
Authors: Poulsen D. K.
Published: December 2007

Calculation of the rate and volume of fluid loss from a hydraulic fracture is important in modeling growth of the fracture. This paper presents a generalized theoretical treatment of fluid loss from a fracture, and avoids the common assumptions of (1) constant pressure drop between the fracture and the reservoir boundary, (2) constant filtration properties, and (3) incompressible filtercake. Separate derivations are made for the laboratory fluid-loss cell, leading to recommendations for the analysis of laboratory data and its translation to the fracture-reservoir system.
A Comparative Study of Wettability Test Methods Based on Experimental Results From North Sea Reservoir Rocks
Authors: Torsaeter O.
Published: December 2007

Three methods are widely accepted for evaluation of the wetting properties of a rock/fluid system: 1) The Amott test, 2) The USBM-test and 3) Contact angle measurements. In this work the Amott test and the USBM-test have been run in a combination procedure on reservoir rock samples, while contact angle measurements were performed on quartz surfaces. Nine core plugs from two reservoirs in the North Sea were tested in native state and then cleaned and retested. The experiments were run at 80°C with separator crude oil and synthetic formation water.

The paper includes a detailed analysis of the experimental results and the experiences gained with respect to wettability testing, apparatus and procedures, core plug preparation techniques, cleaning methods and measurement reproducibility of wettability tests.

The results from the wettability testing show that the Amott index and USBM-index coincide very well, and that a test procedure combining Amott and USBM is superior to single tests. The results also show that the cleaning procedure used in this work did not render the plugs completely water wet. This could be due to content of oil wetted minerals or remaining organic matter.

The results from the contact angle measurements on clean quartz show that the system is more water wet than indicated by the Amott/USBM test. This contact angle behavior confirms the interpretations based on the cleaning and wettability tests.
Dynamic Displacement Measurements of Three-Phase Relative Permeabilities Using Three Immiscible Liquids
Authors: Grader A. S. , O'Meara D. J.
Published: December 2007

The main difficulties to overcome in dynamic displacement relative permeability measurements are capillary end effects and viscous fingering. The latter problem is particularly severe in three-phase systems which include gas. Both of these problems are greatly mitigated in the three liquid system presented here. Water, benzyl alcohol, and decane are the three immiscible liquids which play the role of water, oil, and gas in the conventional three-phase system. The interfacial tensions in this system are about a factor of ten smaller than the comparable tensions for the conventional system, so the capillary end effect is less. Furthermore, viscosity contrasts are diminished, thus lowering the chance of fingering.

An extension of the Welge-JBN method to three phases is derived. Each displacement experiment follows a saturation trajectory across the ternary diagram. The method is used to calculate three-phase relative permeabilities along each trajectory. Finally, the data from all trajectories are combined to provide isoperms over a large portion of the ternary diagram.

Also included are the two sets of two-phase relative permeabilities needed to apply the interpolative three-phase relative permeability model of Stone. The measured isoperms indicate the model over-predict the relative permeability to oil: oil flows at lower rates than predicted.
Experimental Investigation of Retrograde Condensation in Porous Media at Reservoir Conditions
Authors: Danesh A. , Henderson G. D. , Krinis D. , Peden J. M.
Published: December 2007

The phenomena of retrograde condensation and the flow of gas-condensates in porous media under simulated reservoir conditions have been studied experimentally. Depletion tests on a 6 component synthetic gas mixture with a dew point of 33 MPa (4800 psi ) at 37.8°C were conducted in glass micromodels and long sandstone cores. Micromodels with homogeneous and heterogeneous patterns, were employed to observe the mechanisms of gas-condensate flow at the pore level. The micromodelling results were then employed in designing experiments in vertical and near horizontal cores to study the phenomena at larger scale and in evaluating the recvoery and composition of gas and gas condensates.

The observations made on the micromodels revealed that whilst condensate continuity was maintained through thin films, its growth was observed to be non-uniform and strongly dominated by capillary and gravitational forces. The depletion tests on the cores verified pore level observations, and in particular, the minimum condensate saturation for the downward flow of condensate was found to be quite low. Implications of the results on gas-condensate laboratory experimental methods have been briefly discussed.
Petroleum Engineering Manpower Supply
Authors: Bourgoyne A. T.
Published: December 2007

The purpose of this paper is to report the results of the Supply Survey conducted annually by the SPE Manpower Committee. The 1987-88 academic year survey was sent to educators from the 30 U.S. schools listed in the Petroleum Engineering and Technology Schools book published by SPE. Twenty-five of these schools offer degree programs in petroleum engineering and five offer options in petroleum engineering within another engineering degree program. Twenty-eight of the 30 schools responded to the survey.

The survey asks each school to report the number of graduates during the 1987-88 academic year at the B.S., M.S., and Ph.D. levels. The number of non-citizens included in these graduates and the number seeking employment in the U.S. job market are also reported. For those graduates who have reported to their school that they have found employment, the type of employer is requested. The following six employer categories are used:
Horizontal Wells: An Application in the North Sea
Authors: Macdonald C. J.
Published: December 2007

The results of a reservoir engineering study into the benefits of using horizontal wells for the development of the Cyrus reservoir are described and discussed.

The techniques for modelling horizontal wells using conventional reservoir simulation software are presented: of critical importance are the dimensions of the grid blocks containing the wellbore and the calculation of wellbore to grid block transmissibilities.

The main conclusion from the study is that a 550 m (1800 ft) horizontal well can be expected to recover at least one and a half times as much as a vertical well during the lifetime of the field. Furthermore, the horizontal well recovers proportionately more during early time which has significant benefits in economic terms, especially for an offshore development.
Concrete Gravity Substructure for Southern North Sea
Authors: Luedtke R. C. , Woodhead L. , Worrall M. F.
Published: December 2007

Ravenspurn North is a gas field development in the Southern North Sea. A novel feature of the development is the use of a Concrete Gravity Sub Structure (C.G.S.) to support the central gas production and compression facilities. The primary reason for selecting this concept is that it offers a cost advantage over steel jacket options.

Concrete in itself is not novel to the North Sea. Concrete structures have been successfully used in the Northern North Sea, where they have tended to be very large. (100,000 tonnes or more). The Ravenspurn concrete platform weighs less than 30,000 tonnes and consists of a cellular caisson base with three circular concrete towers. Two of the towers support the gas production deck and the third supports the gas compression module.

A significant feature of the Ravenspurn platform is that the integrated production deck weighing 6,300 tonnes will be installed offshore at location using a semi-submersible crane vessel. This feature allows considerable savings to be made in the concrete quantities and the amount/complexity of the mechanical outfitting, with a resulting cost advantage. This saving reduces the size of the platform to such an extent that the concrete Substructure can be totally completed within a dry dock.

This paper describes: -The Field Development Plan, with emphasis on the Central Production Platform.-The feasibility study work which led to selecting Concrete for the substructure.-The foundation considerations.-A description of the C.G.S. and method for building.
The Steipner A Platform: An Efficient Gas and Condensate Installation
Authors: Gudmestad O. T. , Coker J. W. A.
Published: December 2007

The efficient design of the installation for production of Sleipner Øst gas and condensate enabled Statoil to make a breakthrough in selling gas from the Norwegian continental shelf to the European gas market under the Troll gas agreement.

A well defined concept developed by an inter disciplinary group of technical specialists from Statoil in close cooperation with the operation group have laid the grounds for an optimal combination of fabrication and EPC contracts in the detailed design and construction phases.

The technical concept is based upon a realistic compromise between technical and operational requirements with specific emphasis on layout and fabrication aspects and through careful review of required safety and instrumentation needs. Attention has been particularly paid to optimal equipment reserve philosophy to reduce investment costs.

The process design features gas recirculation with accelerated condensate production. The structural design includes a concrete gravity base structure, and an integrated module support frame which incorporates many functions and which could be constructed as two large modules.

Due to use of only 7 modules weighing in the range of 3 - 5000 t, hook-up operations will be minimised to make lifting of the module onto the floating platform inshore the most economic construction method.

The drilling equipment located in the centre of an X-shaped deck with the risers and compressors located about 100 m away from the living quarter provides for an efficient and safe layout. The platform is also an essential part of the gas delivery system under the Troll agreement.
Structural Design in Aluminium: Sources of Technical Information
Authors: Buxton P. G.
Published: December 2007

With increasing interest in weight and cost reduction of offshore structures, the use of aluminium alloy is being seriously considered as an economic structural material. The high cost of the material is balanced by its high strength/ weight ratio compared to steel.

Guidance is given on the background and sources of information related to the United Kingdom Design Codes. Reference is given to Selection of Materials and further Work.

A substantial list of references to standards and publications is given in the Appendix.
Field Development of the Scapa Field: A Marginal North Sea Field
Authors: Chen H. K.
Published: December 2007

The Scapa Field, North Sea was discovered in 197 5. The field is developed with an integrated production/injection subsea template system, tied back to the main Claymore platform. Subsea oil production began in November 1986, only 14 months after Annex 'B' approval. The encouraging results of the extended production test from a deviated platform well and appraisal wells in 1984 and 1985 formed the basis for the field development. The continuous downhole pressure recording, extensive RFT' measurements and other data gathering programmes are essential for successful development of a complex marginal field. The estimate of the recoverable oil has been increased by 25 million barrels (4 million M3). The field development to date owes its success to the combined efforts of a multi-disciplinary team, which resulted in the optimum placement of wells. Although marginal in size the development success to date has resulted in an economically healthy project.
The Veslefrikk Jacket Concept
Authors: Lefranc M. , Austin C. W. , Crowle A. , Brown Aker John , Baerheim M.
Published: December 2007

A new concept for developing oil fields has been prepared by Statoil for the Veslefrikk field in the North Sea.

For this deep- water location (174 m) a combination of a semisubmersible production and quarters unit and a drilling jacket is to be used.

In the effort to reduce the total cost of the project Statoil propose to minimize the steel weight of the jacket and to install it by lifting.

The lifting criteria thus limited the lift weight for the 200 m tall structure to 9800 t which is a challenge for the designers.

Aker Engineering was given the task to further develop the jacket and floater.

A close cooperation of specialists for lay-out; marine operation and structure design led to a jacket design with the following features. –optimization of the equipment weight–rotation of the derrick skid beam and the deck by 45° relative to the jacket.–reduction of the environmental forces by minimizing the size and the number of the structural elements, and systematic use of the shielding effect.–use of a temporary sledge for the load-out and transport conditions.–cast nodes and lifting trunnions–offshore installed tubular insert in the legs and separate deck support frame.

The lift operation is the most critical aspect of the Veslefrikk project. A description of the analysis and the particular requirement of this operation is given.

Finally a description of the installation procedure is presented.