bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Coning Applications
Authors: Sonier F. , Besset P. 
Published: December 2007

Abstract
A recent paper presented last year described a two-dimensional-numerical coning model with radial symmetry. Its main characteristics were:
1. Fully emplicit models with respect to all variables by using the simultaneous solution of the different equations describing the multiphase flow.
2. Representation of wellbore boundary conditions which comes closer to expressing physical phenomena caused by end effects.
The model was checked by the simulation of several cases which had previously been studied on a physical model.
The simulation of actual field cases showed that the model was very efficient. This paper describes:
1. The simulation of an actual field case having a long production history. The geometric and influx characteristics production history. The geometric and influx characteristics of the well are in good agreement with a radial circular geometry. The model restores the production history very correctly.
2. An analysis of sensitivity to some poorly understood petrophysical parameters (capillary pressure, relative petrophysical parameters (capillary pressure, relative permeabilities, anisotropy) has been performed. permeabilities, anisotropy) has been performed.
3. The point arises of assessing the effect of built-in impermeable barriers which may occur in the porous medium as either horizontal or cylindrical screens in the vicinity of the well.

Introduction
Fitting field results with a numerical model usually requires a great many parameter adjustments. In the first part of this paper we describe how, in a field case where most of the paper we describe how, in a field case where most of the characteristics are well known, we have succeeded in recreating the production history while modifying only the following parameters: parameters:
anisotropy ratio
shapes of capillary-pressure and relative-permeability curves
and we describe their influence on the results.
The second part of the paper takes up the problem of well treating for the purpose of delaying the arrival of water or gas. Since the present coning model obviously cannot take into consideration the presence in the pay of a fluid used for well treatment, e.g. foam, polymer, gel, etc., we give an extremely rough diagram of this phenomenon by introducing theoretical barriers having zero permeability and infinite stability in time. This analysis could be conducted because we have at our disposal an accurate and efficient numerical coning model (the presence of an impermeable barrier does not increase calculating time, and less than one minute of CDC 6600 time is required to simulate each case).
Mud programs and drilling problems pertaining to the tertiary Clays and Shales, Norwegian Northsea
Authors: Siem I. 
Published: December 2007

Abstract
Problems encountered in drilling Tertiary clays and shales in the southern part of the Norwegian Continental Shelf and the mud system most frequently used in this area, are reviewed in this paper.
Severe viscosity problems frequently arise while drilling the top 10,000 feet of hole, which predominantly consists of clays and shales, and are the direct cause of several problems like swabbing formation; blocking of flowlines and shaker screens by very soft sticky clay; sticking of drill pipe; and bit and collar balling.
The viscosity problems are the result of lack of solids removal equipment, the dispersing type drilling fluid used which makes the solid separation more difficult, and the facts that the lower 5,000 feet of formation is overpressured, behaves plastically, and has a high montmorillonite content.
A salt solution base mud is discussed as an alternative to the commonly used lignosulfonate system. Hydration tests of formation samples in various salt solutions indicate that low density solid content in the drilling fluid might be controlled more economically by the use of a salt water base mud and centrifuges and fine screen shakers. To date mud properties have partially been controlled in the unsatisfactory manner of discarding old mud and making up new mud.
It is concluded that a saving of 25% on the cost of barite alone seems possible with a salt solution base mud. possible with a salt solution base mud. More important however, are the potentials for reducing rig time and potentials for reducing rig time and consequently cost.

Introduction
This study presents mud programs and drilling problems pertaining to the Tertiary clays and shales in the southern part of the Norwegian Continental Shelf (see Fig. I).
Trials of the Dynamic Positioning of a Drill Ship
Authors: Auberger J.F. 
Published: December 2007

Introduction
Let us go rapidly over file sub-assemblies which compose the dynamic positioning system of a drill ship like the Pelican.
There are essentially four sub-assemblies:
a. a displacement detector of the acoustic position measurement system deducts the horizontal displacement of the ship in relation to its assigned point, from a series of measurements of the length of time of ultrasonic wave transmission between the bottom and surface.
b. dual digital computers having the following functions:
- pace the start of the subsea acoustic system;
- process the data from the acoustic position measurement system to deduct the position displacement;
- work out thruster commands to pass on to the propulsion system;
- check the performance of the parts of the dynamic positioning system and start off the alarms or switches in case of failure.
c. a back-up analog processing unit, using the position displacement system data supplied by a taut-wire inclinometer in order to figure the thrusts to pass on to the propulsion system.
d. a unit for auxiliary measurements, allowing the following data to be gathered:
- measurements directly involved for calculating, like wind direction and velocity, which are used in the control loop for a wind pre-correction;
- corrections of pitch and roll enabling the transmission time measurements to be adjusted to take into account the slope of the plane (in relation to the horizontal plane)where the hydrophones, installed on board, are located to receive the ultrasonic beams for displacement detection.
Stratigrafy Drilling in Deep Water With Aluminum Drill Pipes Application
Authors: Gelfgat M. Y. , Podrazhansky A. M. , Geise J. , Paff G. 
Published: December 2007

Abstract
This paper presents the experience gained with the use of special large diameter aluminum drillpipes (ADP) in the Atlantic Ocean, Norwegian Sea. Gulf of Mexico and Gibraltar Straight. The maximum water depth achieved was 1616 m. Both rotary and down hole motor drilling and coring techniques have been used for drilling and coring in variety of formations – from soil till hard rocks. Various types of retrievable tools are available to offer a spectrum of possibilities.
Dynamic Anchoring and Anti-Heave Slide: Key Device for using Floating Supports on the High Seas
Authors: Delacour J. , Castela A. , Harbonn J. 
Published: December 2007

Abstract
To extend subsea oilfield exploration and exploration to greater water depths, work supports set on the sea-bottom must progressively be replaced by floating supports. Work efficiency progressively be replaced by floating supports. Work efficiency then requires the limiting and, if possible, elimination of movements imparted to such supports by the action of the elements, in particular drift, roll and heave.
Two systems have been developed to meet this objective:
1) Dynamic anchoring which cancels out drift and reduces roll by purposely positioning the support.
2) A surface slide which eliminates the effect of heave.
The operating principle of these systems and practical examples are described briefly in this paper along with the experience gained from using both systems together during the past seven years under a wide variety of operating conditions aboard the I.F.P. experimental vessel "Terebel". It is shown in particular that the great flexibility and adaptability, of these systems make it possible to do the most difficult - jobs on the high seas with remarkable safety and efficiency.

Introduction
The current search for new off-shore oil and gas fields in deeper and deeper waters and the commercial exploitation of these fields have set a trend for the progressive replacement of work-platforms set on the sea-bed by floating supports: ships, semi-submersibles and the like.
Increasing water depths and more hostile seas such as the North-Sea or the ice infested Labrador offshore have made it necessary to use less cumbersome and more efficient mooring systems and to drastically improve platform stability, by reducing such motions as surge, sway, yaw, heave, roll and pitch. pitch. Two devices developed during these last years have gone a long way towards meeting these requirements:
1) Dynamic Positioning, which has solved the difficult problem of fast and safe anchoring in deep waters and which problem of fast and safe anchoring in deep waters and which has brought a Feat improvement in stability by allowing the floating support to head permanently towards the on-coming seas, thus reducing considerably the roll motion.
2) The Heave Compensating Device, which has greatly reduced the vertical motions of any piece of machinery being handled from a floating support.
As early as 1963, the "Terebel", a 900 metric tons experimental vessel of the Institut Francais du Petrole, was outfitted with dynamic positioning and a heave compensator.
This paper describes sonic of the work done by the "Terebel" and how dynamic positioning and heave compensator have made it possible to carry out some operations with relative ease which, otherwise, would have been very difficult, if not impossible.
A Flexible Contracting Strategy Has Streamlined International Drilling Operations: A Case History
Authors: Day J. D. , Carter E. C. , Longmire R. J. 
Published: December 2007

Abstract
The primary goal of a drilling operation is to minimize the time and expense required to drill wells while operating in a safe, prudent manner. Minimizing drilling costs decreases the development cost per barrel threshold necessary to exploit hydrocarbon reserves. Decreasing the elapsed time between acquiring a prospect and evaluating the potential reservoir positively impacts the return on an operator's investment In order to reduce operating costs and to expedite potential production from its international prospects, Marathon Oil Company's Worldwide Drilling Group (WWD) has adopted a flexible contracting strategy. This strategy involves an appraisal of each project's objectives and potential along with the company's existing infrastructure in the area to determine the best type of contract to be employed.
This paper reviews the various contract types including conventional, incentive-based, and lump sum operating rate daywork, limited and full turnkey drilling and integrated service agreements. The contracting philosophies which were utilized offshore New Zealand, Sakhalin Island, Tunisia, Ireland, China, and Gabon, and onshore Argentina and Egypt are described. Cost normalizations, risk premium/management local tendering difficulties, and time constraints are discussed along with their effect on which contract mechanism was selected.
This paper summarizes Marathon's strategy of utilizing contracts which best fit the overall project objectives. Streamlining operations through innovative contract philosophy and economizing on local infrastructure, required personnel, and initial capital expenditures have significantly minimized drilling costs. Selected use of turnkey and limited turnkey contracts have assisted in managing risk in areas where Marathon has had limited experience. Finally, this flexible approach to selecting contract type has enhanced the company's ability to pursue high risk and marginal projects.
The SQI: A Service Quality Index to Measure and Reward Individual Companies Within a Well Construction Partnership
Authors: Sharpe P.J. , Jutten J.J. 
Published: December 2007

Abstract
While partnerships need to be driven by global targets, the success of a partnership is intimately linked to the quality of each partners contribution. The absence of a tool to measure the contribution of each partner led to the development of the Service Quality Index (SQI). Tangible results are described, with examples of how improvement opportunities have been identified and resulted in prioritised investment. The SQI system has enabled individual companies to continuously improve, resulting in the partnership as a whole meeting its targets and delivering wells of increasing value.

Introduction
The Nederlandse Aardolie Maatschappij B.V. (NAM) is the largest operator in the Netherlands, running a fleet of five heavy land rigs, three workover rigs and four offshore rigs. NAM had developed its operations in a traditional manner until 1993 when, in a drive to enable development of prospects that had previously been unattractive, a series of partnerships were formed. The PRO-STAR land drilling well construction partnership was formed in 1994 between NAM, Deutag, Baker Hughes INTEQ, Dowell and BPB Wireline Services.

The Partnership
One of the main foundation stones of the partnership is the Win-Win principle. As such although the partnership has a 30% well cost reduction target, cost reduction has not been achieved by squeezing the partners profit margins. Performance with respect to cost reduction targets serves as the basis for a global profit share arrangement, whereby 50% of cost savings beyond agreed targets are returned to the contractor partners. Cost over-runs are borne by the Operator with no penalties imposed. Industry benchmarking has also been undertaken to measure the performance of the team as a whole.
Each partner contributes to the success or failure of the team, and performance improvement requires each partner to strive for excellence within their own activities. The partnership performance is measured in its totality via comparison to a historical cost model. Prior to the implementation of the Service Quality Index (SQI), no mechanism existed to measure the contribution of individual Companies within the Partnership.
All radical changes result in some degree of scepticism and opposition. The restructuring of NAM's well engineering business was no different. Change has to be sold, and selling change requires hard facts and figures to combat perceptions. In the early days of the partnership the assurances of management were treated with suspicion. Even cost performance improvements and profit share payments were attributed to the vagaries of the historical cost model. Something was missing to aid in demonstrating performance improvement throughout all levels of the organisation.
P. 513^
A Deeper Understanding of Heat Checking, an Old but Frequently Overlooked Failure Mechanism, of Downhole Drilling Components
Authors: Choi H. J. 
Published: December 2007

ABSTRACT
Heat checking, a quench cracking phenomena, is an old but often overlooked failure mechanism of downhole drilling assemblies such as drill collars, drill pipes, heavy weight drill pipes, cross-overs, drilling jars, hardfacings, etc. Heat checking occurs when low alloy steels which have been healed by friction against formation (side load) is rapidly quenched by cool drilling fluids. The susceptibility of drilling assemblies to heat checking increases as drilling practice becomes aggressive. The time has come to properly define heat checking and to develop an in-depth understanding of this phenomena. It has often been misquoted, misunderstood and overlooked among drillers. Heat checking promotes macro- and micro-cracks, mictrostructural changes, hardness changes, iron-oxide formation, or structural changes. To mitigate heat checking-related failure, more in-depth understanding is thus required from metallurgical engineering, mud engineering and environmentally-assisted cracking standpoints. In short, heat checking is a more man one-dimensional problem of quench cracking or drilling operations but involves multi-disciplines.
Horizontal Underbalanced Drilling of Gas Wells with Coiled Tubing Challenges and Experiences
Authors: Cox R. , Li J. , Lupick G. 
Published: December 2007

Abstract
Coiled tubing drilling technology is gaining popularity and momentum as a significant and reliable method of drilling horizontal underbalanced wells, and is quickly moving into new frontiers. To this point, most efforts in the Western Canadian Basin have been focused towards sweet oil reservoirs in the 900 – 1300 metre (3000 – 4300 feet) true vertical depth range, however there is an ever-increasing interest in gas-producing formations. Figure 1 shows a composite vertical section of the horizontal or directional underbalanced wells drilled with coiled tubing in Canada, and also highlights the aforementioned trend towards oil over gas. Significant design challenges on both conventional and coiled tubing drilling operations are imposed when attempting to drill these formations underbalanced.
Coiled tubing is an ideal technology for underbalanced drilling due to its absence of drillstring connections resulting in continuous underbalanced capabilities, as well as its suitability for sour well drilling and live well intervention without surface releases of reservoir gas. Through the use of pressure deployment procedures it is possible to complete the drilling operation without need to kill the well, thereby maintaining underbalanced conditions right through to the production phase. The use of coiled tubing also provides the means for continuous wireline communication with downhole steering, logging and pressure recording devices.
Coiled tubing drilling rigs currently exist in several different forms and setups, but generally consist of a drilling coil, injector to feed the tubing into or out of the well, BOP system for well control and return fluid path, and a control cab and power unit. The coiled tubing drilling equipment used to drill the case studies presented later in this paper consisted of either 60.3mm or 73.0mm (2.375 or 2.875 inch) coiled tubing and injector with a hydraulic power unit with control cabin and accumulator. A coiled tubing hybrid mast unit and substructure complete with V-door, catwalk and pipe racks was used. Pumping equipment included a fluid pumper capable of liquid rates of 0.10-1.5 m3/min (0.6 – 10 barrels per minute), nitrogen pumper capable of 10-120 m3/min (350 – 4250 standard cubic feet per minute), and a nitrogen bulk storage unit of 50,000 m3 (1.8 million standard cubic feet) capacity. When drilling sour gas formations, a chemical injection pump for corrosion inhibition may be used.
Reservoir Engineering Applications to Control Excess Water and Gas Production
Authors: Azari Mehdi , Soliman Mohamed , Gazi Naz 
Published: December 2007

Abstract
Conformance control is defined as any action taken to improve the injection or production profile of a well. It encompasses procedures that enhance recovery efficiency, improve wellbore/casing integrity, and satisfy environmental regulations. Unwanted fluid production in oil- and gas-producing wells is a factor that limits the productive life of a well. The cost of produced water disposal in an environmentally non-threatening fashion may be a major concern for many producers. In addition, control of excess water and gas production improves profitability by allowing additional oil to be produced.
Application of water control technology assists in minimizing water production and maintaining the oil flow rate of a well. Reservoir engineering and well testing play essential roles in characterizing and detecting the problems associated with producing formations and wells.
This paper starts with problem identification in both producing and injection wells. It then covers the behavior and control of several types of reservoirs with different drive mechanisms. Applications of reservoir simulation and well testing in the control of water and gas coning, determination of the amount and the best appropriate treatment application, effect of formation layering, control of relative permeability to water, application of permeability blocking agents, water channeling, secondary recovery, viscous fingering, and polymer flooding are detailed in this paper. In addition several techniques to evaluate the overall success of a conformance control procedure are presented.

Introduction
The purpose of this paper is to identify reservoirs associated with excessive gas or water production and to recommend the proper remediation. Conformance control begins with identifying the source of problem. This requires a thorough investigation of all aspects of well and reservoir parameters. The following is a list of some of the parameters required for identification of reservoir performance problems.–Reservoir permeability and porosity–Relative permeability to oil, water, and gas–Connate water and irreducible oil and gas saturations–Net formation height–Recovery mechanism–Reservoir dip–Oil, gas, and water production rates versus time–Original water-oil contact–Length of time before water production began–Location of all perforations–Fraction of the productive interval completed–Identification of fluid entry locations and the type of fluid entering wellbore (production logging)–Location and continuity of any shale layers–Identification of cement to casing bonding (bond log)
This review is divided into the following four main sections: P. 413
Strategies for Fasttracking Exploration and Development of the Elli/Tau Prospects
Authors: Barstad B. E. , Akers T. J. 
Published: December 2007

Abstract
Esso Norge AS and its partner Enterprise Oil Norge Ltd aggressively pursued fasttracking strategies to allow flexibility and control of the drilling rig in an increasingly tight Mobile Offshore Drilling Unit (MODU) market. In 1995, Esso contracted the semi-submersible drilling rig Vildkat Explorer for four firm and five optional wells, primarily to explore the Greater Balder Area. The longer term contract with the Vildkat Explorer fulfilled several objectives. It ensured the availability of a rig in a tightening rig market; the rig could be farmed out as required giving time to incorporate lessons learned into the planning of the next well to be drilled; and it ensured continuity with the drilling contractor. Esso was also able to drill multiple appraisal locations from a single surface location as needed to assess the size, extent, and quality of the reservoirs.
Upon the start of the drilling program, it was realized that the planned wells presented neither particularly technically challenging or very long wells. The opportunity to save time and money by drilling these wells in an innovative, creative and dramatically different way than the ordinary was seen as remote. Instead, a determined effort was made to exploit the small opportunities for saving time and cost through the mobilization and operation of the rig.
Well 25/8-8S, discovering the "Tau" Field in September 1995, will serve as an example of the operational steps implemented in the pursuit of efficiency.
The commercial development of the "Tau" and nearby "Elli" discoveries, now renamed the Jotun Field, is currently being pursued by Esso and its partners. The selected development concept, with a wellhead platform as opposed to a subsea development, is largely influenced by the current and anticipated future tight MODU market. The manifestation of this tight market is not only in the initial capital drilling costs but also in the subsequent well intervention costs and service unit availability during the life of the field. The decision eliminates the uncertainty of development drilling costs created by the MODU market and allows a greater variety of options for future well interventions.
A project team is currently working towards filing a "Plan for Development and Operation" (PDO) for the Jotun Field early 1997, targeting first oil in second quarter 1999, only some 5 years after the initial discovery.