bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Multiphase Flow Model Predicts Pressure and Temperature Profiles in Wells
Authors: Ozon P. M. , Ferschneider G. , Chwetzoff A. 
Published: December 2007

ABSTRACT
Since 1981, Elf Aquitaine, IFP and Total-CFP have been collaborating to establish a new calculation method predicting multiphase flow pressure drop in wells able to cope with any case of oil or gas production. A flow model has been developed by using fundamental equations of two-phase fluid mechanics. The mass and momentum balances for each phase are considered as well as interactions between phases related to every flow regime. The main flow patterns are taken into account and mechanistically – based relations determine transitions.
The physical basis of this model has been provided by experiments carried out on test facilities generating fluid flow conditions similar to those encountered in production wells. The test loop consists of two 30 meter long flowlines (diameter 3 and 6 in), which can take any inclination from 0 to 90 degrees. The fluids used were condensate, heavy gas-oil, water and natural gas with pressure ranging from 5 to 50 bar.
Experimentation and modelling resulted in the development of the program WELLSIM, which performs calculations of pressure and temperature profiles in vertical or deviated wells. Comparison with data gathered from wells offering widely different production characteristics shows good agreement over the whole range of parameters and the accuracy of the results is significantly better than with conventional methods.
SHALLOW GAS KICKS, Safety Aspects Related to Diverter System
Authors: Nøkleberg L. , Schüller R. B. , Søntvedt T. 
Published: December 2007

ABSTRACT
Drilling through shallow gas pockets in the North Sea and in other areas represent a risk for loss of control with subsequent uncontrolled gas blowouts. The diverter system is intended to convey this gas to lee side of the platform.
Statistics show that the diverter system fail in about 50 % of the cases they are used to handle shallow gas kicks. The flow conditions in diverter systems currently employed in the North Sea are so severe that it cannot be expected that the diverter systems can withstand a shallow gas kick in more than a few minutes. The erosion rate can be as high as 1-2 mm/min, and this is an alarming figure.
Veritec has investigated various forms of severe damages to a diverter system which failed under a gas blowout in the North Sea. The damages were caused by erosion of sand particles at high velocity and malfunction of valves. Calculations indicated high gas velocity (near sonic) in the diverter during the blowout.
Velocity in the diverter system can be reduced by increasing diameter of the diverter lines and throttling (a choke) at outlet. By this combination erosion rates may be reduced with a factor of several thousand. The downhole pressure will not be affected by this improved diverter design.
Analysis of a Polymer Well Treatment in the Beatrice Field
Authors: Clifford P J , Duthie A 
Published: December 2007

Abstract
A polymer injection treatment was carried out in the Beatrice field in 1985. The object of the treatment was to improve vertical sweep in the heterogeneous sands between an injector/producer pair. The process was closely monitored using a variety of standard and non-standard techniques: tracer tests, production logging, pressure interference tests before and after polymer injection, and polymer chemical analysis in produced and backflowed brine. Subsequently, a chemical simulation model was constructed and compared with the field data. It was demonstrated from the field measurements that the polymer had a clear effect on fluid flow patterns in the reservoir. However, the simulations showed that there had been a shorter distance of polymer penetration than assumed in planning the treatment, so that the watercut changes were too small to be observed. The project is significant in giving an informed picture of polymer behaviour in heterogeneous North Sea fields. It also successfully demonstrates the array of measurements needed to predict, monitor and reduce risk in polymer field applications.
Troll High Rate Production Test, Planning and Execution
Authors: Nilssen B. H. 
Published: December 2007

SUMMARY
The high rate production test performed by Norsk Hydro on the Troll East structure during the summer of 1985 with the semi submersible drilling rig Treasure Seeker required that a large number of specially designed, modified or adapted equipment items were used in order to fulfil the test objectives and maintain safe operations. These were: -Jetting tool for casing cleaning.-Gravel pack floor manifold to ease operations.-Surface read out of downhole pressure and temperature through cable on the outside of the tubing.-3 inch I.D. tester valve.-3.7 inch I.D. annulus pressure operated kill valve.-Full bore double gauge carrier.-5 inch I.D. sub-sea test valve.-5 inch I.D. lubricator valve.-5 1/8 inch bore flowhead.-Vertical high capacity separator.-32 channel data logger.
The use of this equipment together with other more commonly used equipment made the test a success.
Netherlands Q/8 – A Development Europe's Smallest Offshore Gas Field
Authors: Petterson M. E. , Tibbitt N. C. T. 
Published: December 2007

SUMMARY
BP brought the Q/8-A offshore gas field on stream in October 1986. Q/8-A is the first fully integrated unmanned offshore development in the North Sea. Estimated reserves of only 37 bcf make the field the smallest offshore gas development in Europe.
Economic development of such a small reserve demanded the innovative use of proven technology. Minimum facilities compatible with safe and efficient operations were designed. An unmanned platform with free water knock-out, glycol injection and a sphere launcher, feeds gas via a pipeline beneath the coastal dunes to a dedicated onshore processing terminal.
A rigorous search for cost reductions during pre-project and project engineering, coupled with the favourable economic climate which the Netherlands provides, led to the viability of this most marginal of field developments.
Several lessons were learned from the Q/8-A development project. A minimum cost development with a short project schedule demands a tightly defined technical statement of requirements. Do not underestimate the level of detailed effort necessary to develop and to operate the smallest of reserves.
Alternative Drainhole Drilling System – Theoretical Background and Practical Experience
Authors: Steenbock A. , Müller-Link D. 
Published: December 2007

ABSTRACT
Increasing the formation flow area is one important way to improve the downhole flow conditions. Drilling drainholes by means of conventional drilling technique can already be seen as state of the art. Beside this conception, the lateral drilling, or the "short radius kick-off"-version, has already proved to be feasable, although predicting angle building and controlling inclination and direction was critical. One big step forward was now done by developing the Articulated Drill String (ADS).
Its principle results in a very good control of the well course and will be described in the paper. Depending on the geometrical layout, build-up-rates up to 90 deg./ l0 m are possible. Steering the bit is achieved by means of a special configuration of stabilizers.
Three field tests have already been performed. The first prototype was tested in a quarry. This hole was surveyed with conventional mine surveying equipment. The accuracy of the predetermined well course was found to be very satisfactory. Two other field tests have been performed in a German oilfield. The depth was approx. 1000 m. Angle was build up to 110 deg. followed by a straight hole section of 40 m in order to reach the attic oil in the reservoir. The well was completed with a slotted liner.
Typical procedures of handling the ADS, drilling, surveying and logging as well as casing and cementing are described in the paper.
Design, Operation and Economic Viability of the First Tripod Tower Platform
Authors: Duncan D. A. , van der Heyden H. 
Published: December 2007

ABSTRACT
The Tripod Tower Platform (TTP) is a simple, fixed steel offshore platform suitable for use in water depths from 10 to 350 metres. The first TTP was designed, fabricated and installed by Heerema in July 1986 for Unocal Netherlands, Inc. Installation of the Unocal Helder ‘B’ platform was accomplished as a single lift and complete offshore installation including hook up took just six days.
The TTP concept can be applied to wellhead and production platforms, as well as accommodation, riser, utility or loading platforms. For shallow waters the TTP can be easily removed after the field lifetime and re-used in other locations.
This paper describes the Helder ‘B’ project and also contains a comparison of the actual cost of this TTP with the cost of a conventional jacket structure for similar duty. The savings in steel weight, fabrication cost, installation and expected long term structural maintenance compared with braced jackets are highlighted to document the cost effectiveness of the Tripod Tower Platform.
Commissioning A Multi-Diameter Subsea Gas Lift System
Authors: Evett Alan , Fuller Joseph 
Published: December 2007

ABSTRACT
This paper describes a dewatering operation on the Texaco Highlander Subsea Production Facility located in the North Sea approximately eight miles north-west of the Texaco Tartan platform.
Difficulties in commissioning gaslift operations on remote subsea wells were attributed to hydrate formation and unsuccessful dewatering after pressure testing. The geometry and changing diameters of the gaslift line were complicating factors.
A new application of foam technology was made and this paper describes the background to the task and gives a record of the practical operations undertaken. The job was successful and the various further applications of this type of technology are discussed.
Petrojarl I – Subsea Systems Installation Experience
Authors: Hewlett Clyde , Shaw Gary , Glorstad T. , Tennoy O. 
Published: December 2007

ABSTRACT
The Petrojarl I is the first purpose-built floating production and extended well test ship designed for worldwide application under the same type of leasing arrangement as a floating drilling rig. All other floating production systems in operation today are designed for site-specific conditions and would require significant modification for other applications. In its present configuration this turret-moored process plant/storage tanker receives production from a single subsea well via either rigid or flexible risers. Stabilized crude is exported by an off-loading system to a shuttle tanker.
This paper reviews the manufacture, testing, installation and early operating experience for the subsea production equipment associated with the Petrojarl I Production/Test Ship (PTS). It provides an overview of the system together with some of the more important design parameters. It also recounts the actual manufacturing, testing, installation and early operating experience for the subsea and other critical systems.
This new type of production system is seen to be technically feasible and is also proving to be an economic success even in current depressed market conditions.
A Complete Subsea Wireline System
Authors: Manzi Brian , Dines Chris , Headworth Colin 
Published: December 2007

ABSTRACT
At the present time there are around 400 subsea completions worldwide and even the most conservative surveys predict a doubling of this number within the next decade.
This paper discusses the evolution and operation of a flexible, self-contained system which makes optimum use of existing technology thereby offering a safe, reliable and economical system for riserless re-entry into any subsea well.
Rotary Cyclone Will Improve Oily Water Treatment and Reduce Space Requirement/Weight On Offshore Platforms
Authors: Gay J. C. , Triponey G. , Bezard C. , Schummer P. 
Published: December 2007

ABSTRACT
A rotary hydrocyclone was developed for the treatment of the produced oily water on offshore platforms. The main advantages of this type of equipment consist in :
– a few second residence time resulting in a dramatic reduction in weight and volume. – higher efficiency when comparing with conventional settling tanks or static cyclones. – insensitivity to the platform motion, – large flexibility in flow rate and in oil concentration in the treated water, – low pressure drop requirement, – easily adaptable to changing field operating conditions, – modular conception facilitating the offshore installation, – reduced maintenance and power consumption resulting in a low operating cost.
This paper outlines the results of laboratory work conducted initially on a static hydrocyclone and on a rotary cyclone scale model, with the reasons for the differences in performance of the both type of equipment.
A field test of a 2 × 25 m3/h industrial rotary cyclone skid is presented and the field performance analysed
Finally main features of the industrial units are presented and a comparison with a conventional treatment is made.
On-Line Current Monitoring Fault Diagnosis in Hv Induction Motors – Cask Histories and Cost Savings in Offshore Installations
Authors: Thomson W T , Chalmers S J , Rankin D 
Published: December 2007

ABSTRACT
This paper presents an on-line current monitoring system for detecting rotor faults in large high voltage 3-phase induction motors. The philosophy and practical advantages of current monitoring are discussed and samples of on-site case histories will verify the effectiveness of the method for detecting broken rotor bars and air-gap eccentricity in the industrial environment. A new computerised diagnostic system with expert system capability will also be described.
Partial Turn Threaded Connector for Offshore Casing, Conductor, and Pile Joints
Authors: Pallini J. W. , Danner L. , Maa T-J. 
Published: December 2007

ABSTRACT
This paper presents a new, patented system for threaded connectors which provides a stable, preloaded, high strength connection for tubular joints. The system consists of a group of design features including special thread contour, multiple start threads, and thread cone taper. The system is substantiated by considerable testing and field experience, which is presented.
Also discussed in this paper are some characteristics of connections which make use of this thread system.
Conventional and Unconventional Kill Techniques for Wild Wells
Authors: Ely J. W. , Holditch S. A. 
Published: December 2007

ABSTRACT
Every year tens of thousands of wells are successfully drilled all over the world. The overall safety record of the drilling industry is quite satisfactory. On occasion, however, problems can arise during drilling where the control of a well is lost. Whenever a well begins to produce uncontrollably, the well is termed a blowout.
Drilling hazards other than blowouts can also occur. It is not uncommon to lose circulation or to have a drill string become stuck. During a completion attempt, mechanical problems can cause the loss of the wellbore. Whenever any of these problems exist, the usual worst case scenario is loss of the well. When a blowout occurs, however, the worst case scenario can be much more serious. It is not uncommon to have loss of life, loss of property, and large volumes of oil and gas produced to the environment. It is quite important, therefore, to minimize the chances of a blowout occurring on any given well.
Even with utmost care, accidents occur and blowouts will result. The first step usually taken by an operator after a blowout has occurred is to call one of the companies that specializes in killing blowouts. After an initial inspection of the wellsite, the blowout control specialist can usually recommend whether a surface kill technique can be used or whether directional wells must be drilled to intersect the blowout well and attempt a kill from the reservoir. Numerous papers have been published that can assist one in understanding what can occur and how to prepare for a typical kill operation.
Case Studies of BHA Vibration Failure
Authors: Mitchell R. F. , Allen M. B. 
Published: December 2007

ABSTRACT
Predicting bottom hole assembly (BHA) vibrations is a complicated problem. Axial, lateral, and torsional vibrations can be coupled and effects such as stick-slip and whirl can magnify the loads. Fatigue, pipe bouncing, and tool joint washouts demonstrate the complexity of the problem.
One type of vibration that can be isolated and analyzed is the rapid destruction of the BHA caused by operating at or close to resonance. At rotating speeds that reinforce the natural vibration of the BHA, the destructive harmonics generate high stresses resulting in very short fatigue life. While other factors may cause BHA failure, a significant percentage of field failures appear to be associated with harmonic vibration, particularly lateral vibration.
A simplified model based on harmonic analysis using finite elements has been found to agree well with field experience. The influence of stabilizer placement, drill string forces, and mass of the drilling mud are included in the finite element vibration model.
This paper consists of 8 case studies involving actual BHA failures. The model predicted lateral vibrations with critical rotation speeds that correspond closely to operating conditions at the time of failure in all of the BHA's studied. In addition, the reversing stress computed for the critical operating speeds exceeded the endurance limits of the connections and occurred at the locations in the BHA's where failures were observed.
These comparisons to field data are the first steps in establishing model reliability, so that it can be confidently used as a tool to select operating speeds or evaluate BHA designs.
Cementing of Liners in Horizontal and High-Angle Wells at Prudhoe Bay, Alaska
Authors: Reiley R. H. , Black J. W. , Stagg T. O. , Walters D. A. , Atol G. R. 
Published: December 2007

ABSTRACT
Standard Alaska Production Company has cemented liners in three horizontal and four high angle (inclination greater than 75°) wells at Prudhoe Bay, Alaska. Cementing techniques which have evolved during the drilling of these wells include off bottom cementing of 7 inch [17.8 cm] liners for gas cap isolation; simultaneous rotation and reciprocation of liners while cementing; and strategic placement of a cement filled formation packer between the gas/oil contact and the oil production interval. This paper describes the development of these cementing techniques and gives details of field operations.
Mobilizing Bitumen Under Reservoir Conditions
Authors: Kaleli M. K. , Farouq Ali S. M. 
Published: December 2007

ABSTRACT
An experimental and theoretical study was conducted of bitumen/heavy oil mobilization under cold conditions, using a solvent, carbon dioxide, and surfactant, to investigate ways of mobilizing bitumen or heavy oil ahead of a displacing thermal front. A rectangular cross-section model was used to carry out experiments simulating a bottom water layer underneath an oil zone. Results showed a strong dependence on solvent slug size, as well as the thickness and permeability of the water zone. Of the methods used, a combination of surfactant and carbon dioxide showed the best performance. Water zone thickness is important, because too thin a water zone leads to high injection pressures, while a thick water zone causes dissipation of the solvent. An optimal thickness seems to be about one-fifth of the oil zone thickness.
A miscible displacement/leaching simulator was extended to include a number of additional effects, notably bitumen transport in the water layer. The efficiency of the leaching process was found to depend on the flow rate, solvent slug size, location of the injection/production points, and the relative thickness of the bottom water zone. A good match of the experimental results was obtained. It was found that a thin bottom water zone is helpful for obtaining initial injectivity, yet not detrimental to bitumen recovery. As in the experiments, a bitumen-to-water zone thickness ratio of 5.0 gave optimal results. The concentration profiles showed that the bottom water zone served as a transport layer for the mobilized bitumen. Upon the injection of a large solvent volume, the leaching process became very inefficient, shown by a sharp drop in the bitumen concentration in the effluent. As much as 85% of the bitumen and 68% of the solvent were recovered in the process.
Hysteresis Effects for Gas Condensate Wells Undergoing Buildup Tests below the Dew Point Pressure
Authors: Economides M. J. , Dehghani K. , Ogbe D. O. , Ostermann R. D. 
Published: December 2007

ABSTRACT
An increasing liquid saturation is observed in gas condensate reservoirs when they undergo drawdown. This liquid saturation is not reversible when the well is subjected to a pressure buildup thus resulting in a hysteresis effect. Hence, once reduced, the effective reservoir permeability does not recover and in a subsequent drawdown, the flow rate remains at largely the same level as before the shut in.
This hysteresis effect is examined and quantified. An existing method to interpret the pressure behavior of gas condensate reservoirs is critiqued and is found appropriate for the time when "steady-state" saturation emerges and as long as relative permeability data are available.
A new method allows the calculation of the "apparent" reservoir permeability at steady state and when employing a step-pressure test then relative permeability data may be obtained from the interpretation.
Environmental Parameters Affecting Neutron Porosity, Gamma Ray, and Resistivity Measurements Made While Drilling
Authors: Koopersmith C. A. , Barnett W. C. 
Published: December 2007

ABSTRACT
Recent technological advances have resulted in development of formation logging sensors contained within drill collars. Environmental parameters affecting natural gamma ray, resistivity, and neutron porosity measurements while drilling (MWD) include borehole size, invasion, drilling rate, and formation exposure time. MWD logs, in many cases, can provide superior quality data as compared with comparable wireline sensors.
Case Study of a Gulf Coast Layered Reservoir Using Multirate Transient Testing
Authors: Morris C. W. 
Published: December 2007

ABSTRACT
This paper presents the results of the first application of multilayer, multirate transient pressure testing techniques to the evaluation of a well located in an offshore area of North America. The primary purpose of the case study was to understand the depletion mechanisms of individual layers within the multilayer reservoir. The evaluation was performed using multirate transient pressure analysis and production logging techniques.
The study, performed in a well with a three-layered reservoir completion, illustrates the potential for understanding many of the production and reservoir system problems found in complex geologic environments like the Gulf Coast. The reservoir parameters (permeability, skin factor and pressure) were estimated for each of the layers and the results were compared to those from conventional analyses. The results indicate that the depletion mechanisms of the separate layers are different and that production may be lost because of aquifer water influx from one layer. The understanding of the real reservoir behavior allows workover procedures to yield the optimum hydrocarbon recovery.
Multilayer well test techniques were used, i.e., sequential flow tests with continuous downhole flow rate and pressure measurements at the top of each layer obtained using production logging tools. The analysis techniques utilized for the multilayer reservoir evaluation include convolution, deconvolution, pressure derivative and rate normalization. The interpretation was substantiated using a nonlinear regression to fit the measured downhole flow rate or pressure data with a layered reservoir model.
This case study shows that these advanced reservoir evaluation techniques can have widespread applicability in offshore wells. The multilayer testing technique can be used as a monitoring device to develop pressure depletion profiles of different layers and optimize the recovery of reserves.