bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Rheological Equipment for the Characterisation of Hydraulic Fracturing Fluids
Authors: de Kruijf Alexander , Davies D. R. , Fokker P. A. 
Published: December 2007

Abstract
Two novel rheological devices for measurements on hydraulic fracturing fluids have been developed. The helical screw viscometer (HSV) can be used to study the rheology of fracturing fluids such as crosslinked gels and proppant-laden slurries. The dynamic settling tester (DST) has been designed to measure proppant settling velocities in flowing hydraulic fracturing fluids. This paper will discuss the principles of the new equipment and its applications in the field of hydraulic fracturing. The HSV can be used e.g. to study the slurry rheology of fracturing fluids, the relation between the chemistry and flow mechanics of borate-crosslinked gels and the compatibility of resin-coated proppants and fracturing fluids. The DST has proved highly effective for studying the fundamental properties of the complex fluids typically used for hydraulic fracturing treatments. Completely unexpected phenomena - such as a decrease in proppant settling rates due to shear of a shear-thinning fluid — have been identified.
Acidization-Induced Formation Damage: Experimental and Modeling Studies
Authors: Gadiyar B. R. , Civan Faruk 
Published: December 2007

Abstract
The results of laboratory experiments conducted to investigate the effect of matrix acidization on long berea sandstone cores (6"-12") and their theoretical analysis are presented. Both damaged and undamaged core samples were treated with different concentrations of HCl/HF acids (4%HCl/1.5%HF and 12%HCl/3%HF). One undamaged core sample was treated with 6%HF acid. The effect of spent acid on permeability was investigated. The treated cores were cut into four sections each and the mineralogy of each section was analyzed using an X-Ray Diffraction (XRD).
A simplified model for matrix acidization induced formation damage was developed and facilitated to analyze the laboratory test data and to determine the relative affects of adverse processes in matrix acidization. The model developed takes into account the change in concentrations of both acid and minerals, thereby predicting the change in permeability.
The results indicated that higher concentration of acid causes more formation damage due to the precipitation of silicates and/or iron oxides. In addition, when the spent acid resides in the core for a longer time it causes a severe formation damage.
It is shown that the experimental and simulation results agree well within the accuracy of the simplified model.
The Miller Field: Appraisal and Development Formation Damage Experiences
Authors: Adair Paul , Smith P. S. 
Published: December 2007

Abstract
The Miller field lies in blocks 16/7b and 16/8b of the UKCS and was discovered in 1982. The Miller reservoir is an Upper Jurassic submarine-fan sandstone with a typical true vertical depth of 13,200 feet (4000m). The field currently produces circa 125mbpd from seven wells. The oil contains 11% by weight of carbon dioxide and the gas typically contains 200 ppm (vol/vol) of hydrogen sulphide. General reservoir fluid parameters are listed in Table 1.
Coiled-Tubing Case Histories
Authors: Leising L. J. , Rike E. A. 
Published: December 2007

ABSTRACT
The total number of coiled tubing drilling (CTD) jobs worldwide has grown from 4 in 1991 to 11 in 1992 and will probably exceed 25 in 1993. While CTD still represents only a small fraction of the worldwide drilling market, the growth rate indicates CTD is a technology that is rapidly coming of age. This paper summarizes the jobs performed to date and charts the applications in an effort to predict future trends.
In addition, one specific case study is presented for a well in Alaska. This well was drilled through tubing and underbalanced, thus saving the cost of pulling the completion tubing and preventing formation invasion damage. Coiled tubing is routinely used for live well intervention; its use allows an accepted, safe method for underbalanced drilling.
Underbalanced drilling is appropriate for many mature and depleted field re-entry projects and offers a method of both preventing invasion and increasing productivity while enhancing natural flow and ultimate recovery. In addition, differential sticking is eliminated and penetration rate is greatly increased.
Installation of Monopod Production Structures Using Jackup MODU's
Authors: McRae L. D. , Montoya A. C. , Keaton C. P. , Ettle R. E. 
Published: December 2007

ABSTRACT
Jack-up Mobile Offshore Drilling Units have been used to set monopod production structures in the offshore waters of the Gulf of Mexico. The monopod caisson is towed to the site, picked up with the traveling gear, ballasted with salt water, uprighted and driven with a diesel hammer. This procedure obviates the need for a derrick barge to set a jacket thus eliminating scheduling problems and reducing costs.
Solution of Common Stuck Pipe Problems Through the Adaptation of Torque/Drag Calculations
Authors: Haduch G. A. , Procter R. L. , Samuels D. A. 
Published: December 2007

ABSTRACT
Stuck pipe conditions require fast and effective response. This paper describes a method through which torque/drag calculations can be adapted to quickly and accurately answer the three most often asked questions associated with stuck pipe situations. This approach is used to determine:
the force at the stuck point given any measured weight the measured weights required to set and trip a jar the measured weight required for backing off at a given depth
The method correctly accounts for the critical role which drag forces play in these calculations. Further significant enhancements over previous methods are provided by taking into account both the operating condition at the time of sticking and any subsequent surface action taken by the driller before stopping operations. The integration of this methodology with currently available torque/drag analysis software, provides the drilling engineer with a wider range of solutions for problems associated with day-to-day operations.
The theoretical basis for this method is summarized, and drillstring behavior prior to, during, and after sticking is explained. An understanding of friction effects and their impact on the final solution is emphasized. A wide range of operational cases are presented, and comparisons showing important benefits over other calculation methods are included.
Mud-Gas Separator Response to Well Control Procedure
Authors: Williamson M. D. , Dawe R. A. 
Published: December 2007

Abstract
A gas kick is removed from a wellbore by applying well control procedure. The large volume of flammable gas brought to the surface is directed toward the mud-gas separator, MGS, where it is separated from the mud and safely disposed of. However, the gas flow rate may become so large that the MGS overloads. Under these circumstances, significant amounts of hydrocarbon will be released onto the rig floor causing a risk of explosion. This situation poses a serious danger to rig personnel and equipment.
Advanced gas kick simulators are now available that can predict the flow properties of the fluids entering the MGS as functions of time during the well control procedure. The availability of such detailed information presents an opportunity to understand the response of the MGS to well control procedure. This detailed information allows the development of models of the MGS that predict MGS parameters with greater precision than existing methods will allow.
In this paper, models of the physical processes that occur at the MGS are developed. These models have been combined to produce an algorithm which, together with simulated well control data, can estimate MGS parameters as functions of time during the well control procedure. This algorithm will be useful to office based drilling engineers preparing rig safety cases during the well planning stage of drilling a well. The use of this algorithm will result in better selection of well control procedure, MGS operation and sizing, and better contingency plans for altering the well control procedure or MGS operation should the need arise.
A Discussion on Casing Settling During Shallow Gas Blowouts
Authors: Adams N. J. , Kuhlman L. G. 
Published: December 2007

ABSTRACT
This paper discusses an aspect of shallow gas blowouts not previously addressed in prior published works. The topic considered is the effect of blowouts on settling of casing strings. Some field cases have resulted in complete loss of the pipe in underground caverns while others have shown no settling, in some cases, subsea BOP stacks were lost with the casing. Deep blowouts and casing settling will be discussed also.
This paper will consider 7 field cases as examples of the event. Some cases had settled or lost casing while others remained undisturbed and intact. The paper presents hypotheses on settling causes.
Recommendations will be given on procedures to diagnose the probability that pipe will settle and give some field procedures on how to prevent or control pipe settling.
Shallow gas flows on production platforms have resulted in settling of the blowing well and also settling in other producing wells on the platform. Examples will be given. Control problems will be discussed.
The First 12 Snorre Field Wells: Accelerating the Learning Process
Authors: Oftedal T. O. , Ledsaak J. P. , Pollard M. G. , Hjellen A. P. , Elks W. C. , Haut R. C. 
Published: December 2007

Abstract
This paper discusses the experience gained by Saga Petroleum during the drilling and completion of the first 12 wells at the Snorre Field as well as the systems developed to help maximize the learning curve. Included in the paper are specific examples of how the drilling and completion times at Snorre have been reduced.
Reducing Downtime Due to Top Drive: The $1000 Bet
Authors: Ogidan Biodun 
Published: December 2007

ABSTRACT
From 1982 when the first TDS (Top Drive System) was introduced to drilling to 1993 when over 350 units were operating worldwide, there have been over 100 service bulletins issued by Varco (the TDS main supplier). These bulletins in conjunction with 5 major upgrades to the equipment have contributed to improvements in its operating performance and safety in operations. The bulletins and upgrades (= improvements) have been driven by continous feedback from TDS users worldwide.
Inspite of the improvements haven been made, the tool remains a significant cause of rig downtime if not well managed.
Sedco Forex, was the first drilling contractor to install a Top Drive on its rig (the Sedneth 201 & 202 in 1982) and has the highest number of Top Drives in use worldwide. Consequently, there was a need by the drilling contractor to develop and monitor a program to reduce TDS downtime. Analysis showed that 20% of rig downtime was accountable to this equipment. This analysis was conducted using performance data taken from 36 rigs over a period of 3 years. Half of these rigs were fitted with Top Drives.
This downtime coupled with high maintenance cost and expensive upgrades of the equipment translate into over $200,000 cost per TDS unit per year. To address this issue, as an incentive, Sedco Foiex and Varco each pledged a nominal $1,000 lumpsum bonus/malus per TDS unit, payable by either party to the other, dependent upon improvements being made to Top Drive related downtime. The goal was to reduce TDS downtime by 30% within a year. Varco would earn the bonus / incur the malus if the goal was / was not achieved.
During the first 5 months of the incentive agreement, it was observed that both parties profited to a degree far greater than the original pledge.
This paper explains the virtual approach taken by the two companies to achieve a true win-win situation, and demonstrates the benefits to be gained through a simple and practical contractor - supplier alliance.
The paper concludes that there is a potential saving to the oil industry of several million dollars by reduction of TDS related downtime.
Complete System for Continuous Coring With Retrievable Tools in Deep Water
Authors: Gelfgat Michael , Gamsakhurdia George , Geise Joost , Spierings Henk 
Published: December 2007

ABSTRACT
Drilling shallow stratigraphic boreholes in deep water is an important component leading to reduction of exploratory costs. The Complete Coring System (CCS), using special retrievable tools and large diameter aluminium drill pipes has proved to be a possible way to perform this task. CCS combines experience of Russian continental scientific drilling techniques with ODP research efforts and is represented by several coring methods along with sequential drilling using a retractable bit and logging without tripping of the drillstring. Separate units of the system have been used both onshore and offshore in different geological conditions. In 1993 CCS has been utilized for drilling in 1500 m water depth offshore Norway.
A Computer Programme for Drilling Hydraulics Optimisation Considering Realistic Rheological Models
Authors: De Sá C. H. M. , Martins A. L. , Amaral M. S. 
Published: December 2007

ABSTRACT
Drilling fluids while circulating in oilwells are submitted to a wide range of shear rates, varying from very low values (in the mud tank or in riser/drill pipe annular region) to very high ones (through the bit nozzles).
It is common sense among rheologists involved in the area, that the conventional rheological models (Bingham and Ostwald de Waele) do not represent adequately the behaviour of drilling fluids in such a wide range of shear rates. Other rheological models have been proposed to characterize drilling fluids. However, their current use in the design and supervision of drilling operations is not overspread yet.
Since most drilling rigs today have computational facilities, there is no longer necessity to use inaccurate models for engineering calculations. Adequate rheological characterization is an essential starting point for several calculations, such as hydraulics, cutting transport, kick control, etc.
This paper presents a procedure for drilling hydraulics calculation based on dial readings at the six available rotation speeds of the conventional oilfield viscometer, calculation of five rheological models and use of specific friction loss correlations for each model. An user friendly computer program was developed for optimum flow rate calculations based on this procedure and validated with data obtained from a real scale well. The program was developed based on the requirements of several drilling activities such as offshore operations, compressible fluids, high angle wells, etc.
Interactive Modelling of Multiphase Inflow Performance of Horizontal and Highly Deviated Wells
Authors: Alvestad Jostein , Holing Kent , Christoffersen Kjell , Langeland Ole , Stava Ole 
Published: December 2007

ABSTRACT
An interactive system for modelling of multiphase inflow performance of long, highly deviated and horizontal wells is presented. It's prime areas of use are design of well trajectories and completions, and evaluation of wells inflow performance including calculation of well indices for full reservoir simulation. Further, the system provides a basis for improved integration of the reservoir engineering and the well completion design. The reservoir pressure and multiphase flow distribution is modelled accurately using a finite element method combined with automatic local grid refinement around wells. A comprehensive multiphase wellbore flow model is available for accurate flow modelling in the wellbore. A well inflow model including a generalized formula for calculation of well indicies of wells in arbitrary directions is proposed. Examples are given showing improved inflow performance calculations using the new well indices.
Downhole Material Selection for Clyde Production Wells: Theory and Practice
Authors: Blackburn N. A 
Published: December 2007

ABSTRACT
The Clyde oilfield lies within North Sea block 30/17b. First oil was produced from the field in March 1987.
Wells drilled during field appraisal indicated a potentially, highly corrosive downhole environment. Although high chromium content (Duplex) steels appeared to be the technically preferred completion material a decision was taken to use carbon steel tubulars.
Historical data has shown that carbon steel gives acceptable performance in the large majority of production wells. Failures have occurred but these have been highly specific and related to high fluid velocities and increasing watercuts. A "mixed" string completion employing carbon steel, 13 Cr and plastic coated tubing has been successful in controlling downhole corrosion in these few problem wells.
This paper reviews the downhole corrosion control strategy used on the field and shows how carbon steel may be used successfully in a severe downhole environment.
New Polymer Gels for Reducing Water Production in High-Temperature Reservoirs
Authors: Albonico Paola , Bartosek Martin , Lockhart T. P. , Causin Emilio 
Published: December 2007

ABSTRACT
Selected complexing agents are used to achieve the delayed gelation of Cr(III) crosslinked acrylamide polymer compositions to temperatures as high as 150°C. With these retarding agents formulations based entirely on inexpensive, commercially available materials have been developed that display gelation characteristics suitable for a wide range of reservoir treatments at elevated temperature. Studies on Cr(III) acetate show that Cr(III) propagation in porous media degrades sharply at elevated temperature. The presence of the retarding agents significantly reduces Cr(III) retention and enhances the stability of Cr(III) in solution. The mechanisms underlying this behavior and the implications for gel treatments in reservoirs at elevated temperature are discussed.
Using Simulation To Assess Manning, Skills and Logistics Requirements for High Productivity and Low Life Cycle Cost
Authors: Gray C. G. , Aase B. K. 
Published: December 2007

Abstract
Statoil has cooperated with Hunting Engineering Ltd. to establish a simulation software tool applicable to offshore industry needs. The software has been named AIMLO (Analysis of Installation Manning, Logistics and Operations).
The purpose of this paper is to show that a simulation model of this type can be used to determine how manpower and installation productivity are affected by:
Installation characteristics, including:
Type of equipment installed
Criticality of main functions
Failure modes and Mean Time Between Failures
Events/Failures that require an immediate visit
Maximum number of men allowed on the platform
Manpower characteristics, including:
Location of the maintenance crew
Each man’s skills
Shift patterns
Logistics support levels, including:
Alternative transportation routes and times
Availability of a helicopter
Operating and maintenance policies, including:
Maintenance strategy
Type, amount and frequency of workload activities
Required skills and seniorities
Other activities
Control philosophy
Intervention philosophy
The model results can make a significant contribution to the design and policy decisions which impact on the operational availability and whole life cost of an installation.
The paper is presented in two parts. The first part describes the application of the model to a specific project. For commercial reasons the quantitative information derived during this study is omitted from the paper. The second part describes the origins and nature of the simulation technique, and how it may be developed in the future.
Critical Issues in Hydraulic Fracturing of High-Permeability Reservoirs
Authors: Cleary M. P. 
Published: December 2007

SUMMARY
The paper focuses on the sub-class of issues which can affect/dominate the performance of hydraulic fracturing in (gas or oil) reservoirs with higher-permeability, of order lmD (10mD) or more in gas (oil) reservoirs. These issues are placed in the broader context of five major aspects which have been newly extracted from data-analysis over the past five years and which have greatly polarized/reversed industry thinking on hydraulic fracturing: heretofore, primary implications have been for lower-permeability reservoirs, where convection and tortuosity constraints impose a narrow (or non-existent) window for successful design of fracture treatments, especially in light of properly-interpreted higher net fracturing pressures (than conventional industry models) induced by nonlinear rock response to (multiple) fractures. A much wider design window has made successful stimulation of higher-permeability reservoirs relatively easy and economically more rewarding, a result surprising to some. Perhaps more surprising are conclusions that appropriate proppant concentration may vary somewhat inversely with reservoir permeability and that fractures may preferentially grow (vs. initiate) in lower- permeability strata/sections, the main theme of this paper. Fluid rheology also plays a much more important role in (leak-off behavior during) fracturing of high-permeability reservoirs vs. a lower-permeability role limited to near-wellbore (tortuosity) response. Some issues are illustrated with simulations performed by a unique computerized system, which allows credible matching of (treatments and production) data over a wide range of reservoir, fluid and job parameters - thereby allowing establishment of conclusions with case-histories, supported by some careful laboratory experiments. With the aid of this computerized capability, dramatic results have been achieved in reducing job costs and improving production, especially for low- to medium-permeability reservoirs, but many of the implications can be carried over to high-permeability reservoirs.
Asphaltene Deposition Monitoring and Removal Treatments: An Experience in Ultra Deep Wells
Authors: Galoppini Maurizio , Tambini Mauro 
Published: December 2007

SUMMARY
An anomalous decline in production parameters has been observed since the beginning of the productive life of wells in the ultradeep Villafortuna-Trecate (VF-TR) field in northern Italy owing to the deposition of asphaltenes within the formation and tubing string.
This paper discusses the procedures that have been developed for monitoring well productivity performance based on the measured surface production parameters. These data are processed by means of well performance analysis in order to obtain a so-called Equivalent Productivity Index which is correlated with the Cumulative Production and has been used to determine when and if to carry out remedial solvent treatments, and to optimize the volumes and field treatment procedures.
Case histories of the most significant experiences are reported, including the results of production logs. These clearly show the progressive plugging of perforations owing to asphaltene deposition and the subsequent action of the solvent/acid treatments.