bluuebunny/crossref_metadata_2025_split huggingface dataset:
New-Generation Retrievable MWD Tool Delivers Superior Performance in Harsh Drilling Environments
Authors: Hache Jean-Michel , Till Paul 
Published: December 2007

Abstract
As the search for recoverable oil reserves moves to smaller, deeper, and hotter wells, measurements while drilling (MWD) requirements have grown increasingly challenging. MWD tools must survive temperatures of up to 350°F (175°C), pressures of up to 22,000 psi, and a wide variety of mud conditions. Moreover, deeper wells cause higher attenuation of the MWD signals and therefore require more signal power downhole. This paper presents the development of a new-generation retrievable MWD tool that has been proven to deliver the reliability required by the industry, even in deep, high pressure, hot wells.
Four case studies illustrate the tool's reliability and performance under extreme conditions:
In the Villafortuna field in Italy, this new generation MWD tool drilled the deepest horizontal well in the world, at depths greater than 20,000 ft with a maximum circulation temperature of 356°F (180°C) and downhole pressures exceeding 20,000 psi. In the Gulf of Mexico, the tool enabled BP to complete a deepwater well at a depth of 26,442 ft with a flow rate as low as 62 gpm, extending the far reaching capabilities of slimhole MWD equipment. In the Austin chalk in Texas, the tool operated reliably in drilling muds containing 30% solids. The tool operating life was increased by a factor of three through design improvements. The final case study documents the benefits of a tool designed for extreme environments, when used in difficult but not extreme conditions. An exemplary run of 315 hours at 287°F (142°C) is discussed.
This new generation of slimhole MWD technology finally meets the challenges presented by the deeper and hotter wells at the leading edge of petroleum exploration.
Casing Drilling: An Emerging Technology
Authors: Shepard S. F. , Reiley R. H. , Warren T. M. 
Published: December 2007

Abstract
Casing Drilling, an innovative process for simultaneously drilling and casing a well, is emerging as viable technology for the twenty-first century. The concept builds upon experience gained drilling liners to bottom in troublesome holes. With the advent of dependable top drive systems, wireline retrievable bottom hole assemblies, PDC bits, and high torque connections, it is possible to simultaneously drill and case a complete well using casing as the drill-string.
BP used the Casing Drilling process in Wyoming to drill both the surface and production casing intervals for five gas wells. These wells range in depth from 8,200 to 9,500 feet. This paper provides a case history discussion of critical issues that were encountered and resolved during the planning and operations phases of the project.
Lost Circulation Control: Evolving Techniques and Strategies to Reduce Downhole Mud Losses
Authors: Bruton James R. , Ivan Catalin D. , Heinz Thomas J. 
Published: December 2007

Abstract
Owing to the economic, well control and drilling efficiency problems it propagates, preventing or curing lost circulation has evolved into a critical issue for the industry. Accordingly, a less expensive drilling fluid system often is selected for a particular interval because it will mitigate the economic ramifications of downhole losses. Conversely, fluid systems are also chosen solely for their capacity to minimize losses downhole. Regardless of the application, special analyses are required to not only determine specific preventative measures for drilling fluid loss, but also for devising an appropriate treatment program to cure losses should they occur. Recently, specialized and chemically activated cross-linked pills (CACP) designed to stop whole mud loss have been developed and have shown significant advantages over conventional loss circulation methods.
This paper describes the development and application of the specialized cross-linked pills for controlling downhole mud loss. The authors will detail the laboratory methods used to formulated appropriate formulations, the placement procedures, and the successful field applications of this latest generation lost circulation control mechanism.
As detailed in the paper, formulations of the new cross-linked pills normally are tailored to specific downhole conditions of temperature and pressure to create a barrier between the loss zone and the wellbore. Further, they have been specially formulated to enable pumping through narrow drill pipe, coil, or mud motor dimensions and to "set" in a specific time frame. Chemical activators or retarders to control setting times achieve this.
These pills also contain controlled concentrations of particulate sealing agents that can be used selectively to either to bridge the loss zone at the formation face or allow deeper penetration into the fracture.
Case History of the Removal of a Hydrate Plug Formed During Deep Water Well Testing
Authors: Reyna E. M. , Stewart S. R. 
Published: December 2007

Abstract
The potential for gas hydrate production is always present in deep water operations. The negative impact of gas hydrate formation on both drilling and completions activity in deep water has been documented previously1,2. Another speciality operation that holds equal hazardous potential is drill stem testing in deep water. This paper describes the cause and solution to a hydrate plug that formed during a deepwater well test operation off the UK Continental Shelf, West of Shetlands. During well test operations in a water depth of 2750', an 800' hydrate plug formed in the string inside the riser above the mud line, prohibiting communication with the well below the SSTT. Diagnostic tests were carried out to determine the source of the blockage, and two potential culprits were initially identified - paraffin or hydrates. Coiled Tubing was mobilised to attempt removal using a heated glycol / brine solution. After several diagnostic operations, a coiled tubing jetting assembly and finally a mill and mud motor was successful in safely removing the hydrate blockage.
This paper will discuss: ➢How hydrate formation was masked by other aspects of the well test➢The technical and operational issues considered while developing the procedure for removal of the hydrate plug➢The outline of the final procedure➢The result of the execution➢The lessons learned
Integrated Borehole Stability Studies: Key to Drilling at the Technical Limit and Trouble Cost Reduction
Authors: van Oort E. , Nicholson J. , D‘Agostino J. 
Published: December 2007

Abstract
Drilling the Limit (DTL ™) is a powerful initiative to drill wells at minimum time and cost using best-in-class technology. Pre-requisite to drilling at the technical limit, however, is that the borehole is "perfect", i.e. the borehole is stable enough to eliminate downtime from stuck pipe and lost circulation incidents, the annular clearances are sufficiently free from cuttings to minimize wiper trips etc. This requirement is nontrivial when drilling challenging wells, e.g. wells drilled at high deviation and extended reach in reactive formations, wells in tectonically active areas, wells in deepwater environments with very small drilling margins etc. Achieving the "perfect" borehole for such wells is facilitated by including an integrated borehole stability (IBS) study in the well planning phase and by implementing its guidelines during well execution. A review of the IBS process is presented in this paper with actual examples of IBS results that were used to enable DTL ™ and minimize trouble costs on challenging wells.
Cost Effective Composite Drill Pipe: Increased ERD, Lower Cost Deepwater Drilling and Real-Time LWD/MWD Communication
Authors: Leslie J. C. , Jean Mr. Jeff , Truong Mr. Lee , Neubert Mr. Hans , Leslie II Mr. James C. 
Published: December 2007

Abstract
Extended Reach and Deep Water Drilling are constrained by the weight of the steel drill pipe. Transfer of data between the bottom hole assembly and the well head is currently cumbersome, slow, and less precise than desired. Recognizing these limitations, the U.S. Department of Energy, National EnergyTechnology Laboratory, has funded a three-year program to develop and qualify a cost-effective composite drill pipe (CDP). This pipe will provide enabling capability in all three of these areas. The program was started on September 30, 1999 and has the goal of having composite drill pipe approved and commercially available by September 30, 2002.
This paper reviews the first year of the program, presents specifications for the proposed composite drill pipe, and represents work-in-progress.
Solid Expandable Tubular Technology – A Year of Case Histories in the Drilling Environment
Authors: Dupal Kenneth K. , Campo Donald B. , Lofton John E. , Weisinger Don , Cook R. Lance , Bullock Michael D. , Grant Thomas P. , York Patrick L. 
Published: December 2007

Abstract
Maximizing hole conservation while optimizing well economics in both conventional and deepwater wells is a continual challenge. Addressing these challenges with new technology has provided some significant solutions, but the uncertainty when utilizing new technology with no proven track record must be risk-weighted.
Solid Expandable Tubulars (SETs) have been installed in both openhole and cased-hole wellbores from November of 1999, in a variety of environments in wells on land, offshore and in deepwater to solve a range of drilling and completion challenges.
This paper will discuss the drilling case histories in depth including: Descriptions of drilling challenges surrounding the use of SETs and their next best alternativesRisk analysis leading to the use of SETsDiscussion of the advantages and disadvantages of using SETsOperational lessons learned during installations of SETs
Breakthroughs in Casing Running Efficiency Utilizing Modern Pipe Handling Technology
Authors: Woelfel S. R. , Vollands P. T. 
Published: December 2007

Abstract
As the Drilling Industry demands continuous improvement in both safety and efficiency, many newbuild rigs in the recent newbuild cycle have turned to automation in the form of Varco Systems advanced Pipe Racking Systems (PRS). This paper will focus on one key area of the drilling process – casing running, and will address the significant operational effect that the additional casing strings required for deepwater pose to the well construction process. Recent operational performance of Pipe Racking Systems on the Transocean Sedco Forex ultradeepwater drillship Discoverer Enterprise will be reviewed.
The paper will also discuss the technical hurdles that were overcome in the design of an offline pipehandling system used to build 135-ft stands of triples of casing and rack them back in a dynamic application.
The technical discussion will be complemented by a review of how planning and execution of tubular operations have changed to maximize rig efficiency and safety. Results over the last year on the Discoverer Enterprise indicate running speeds of over 40 joints of range III casing per hour are attainable.
The Technical Limit - Illusion and Reality
Authors: Marshall David W. 
Published: December 2007

Abstract
The Technical Limit is a means of achieving a step-change in drilling performance the application of which has resulted in an improvement in operational performance against previous benchmarks. This is the reality. However, this paper will endeavour to demonstrate that the Technical Limit does not, by itself, optimise well construction costs since a significant proportion of this cost is not impacted directly by the Technical Limit approach. This is the illusion.
The paper examines the cost structure of the well as complementary to the Technical Limit's analysis of the time structure. It further emphasises the importance of the application of project management techniques to the well construction process and the necessity to include the typically ancillary functions of finance, contracting and procurement within the core well construction team in addition to the traditional operational skills. Competence assurance of these ancillary functions is as important as the core engineering function in order to optimise the well construction costs.
Evolution Toward Simpler, Less Risky Multilateral Wells
Authors: Pasicznyk Adam 
Published: December 2007

Abstract
This paper discusses a paradigm shift in multilateral technology. The new focus is away from increasingly complex completion installations and toward simple yet highly functional multilateral completions.
This paper reviews the TAML multilateral classification system, then traces Level 3 multilateral completion technology from original to current configurations. This latest iteration retains simplicity while adding full reentry functionality into both the main bore and lateral completions. The discussion then addresses pre-engineered Level 6 multilateral solutions that, by definition, uniquely embrace simplicity while providing optimal functionality.
Following this discussion, case studies from Venezuela, Nigeria, and the United States illustrate installation procedures, operational issues, resulting efficiencies and economies, and opportunities to further improve the technologies.
A New Approach to Borehole Trajectory Optimisation for Increased Hole Stability
Authors: Awal M. R. , Khan M. S. , Mohiuddin M. A. , Abdulraheem A. , Azeemuddin M. 
Published: December 2007

Abstract
Borehole instability due to stuck pipe, hole pack-off, and lost hole during drilling has been a major problem, which causes the industry to lose millions of dollars.
In the last two decades, various rock mechanics principles have been tried, and experience has been shared in the literature as to the efficacy of these principles to minimize the problem. The commercial software, rich in such analytical and numerical models, however, have not mitigated the problem.
We have found that this failure is attributable to:lack of full utilization of the classical Kirsch equations that represent the state of stresses around a borehole;negligence/ignorance of the complete in-situ stress field and the Biot's constant; and improper calibration of the rock mechanics parameters; andlack of translating the findings of mathematical models in an appropriate form that can be readily used for field deployment.
We have addressed these shortcomings by utilizing more relevant solutions to the Kirsch equations by incorporating poro-elastic behavior of rock. Further, we have utilized hitherto neglected aspects of the geomechanical stability equations, and presented graphical solutions that can be used by field engineers having a minimal knowledge of rock mechanics.
One of the important findings of these computer generated, graphical solutions is that the optimized trajectory can be vertical, inclined, or horizontal. This depends on whether the region is tectonically quiet or active. It also depends on whether or not, the prevailing insitu stress regime is normal, overthrust/reverse, or strike-slip type. Thus, the principal insitu stresses, in both magnitude and directions, are a fundamental data set that is needed in designing the safe borehole trajectory. For the deviated hole, further optimization is obtained by determining the best azimuthal direction to reach the target zone. What is more interesting, the optimized trajectory requires a much less mud weight to drill a stable borehole, thereby reducing drilling cost significantly.
We have applied our method in a case study in an offshore field, where frequent borehole collapse has been reported in drilling through shale/sand stringers. The successful application of the proposed method would not only save millions by preventing borehole instabilities, but also cut drilling cost significantly by replacing the expensive and environmentally unsafe oil-based mud.
Acid Stimulation Optimization in Horizontal and Vertical Gas Wells
Authors: Rocha G. , Hanbouly H. H. 
Published: December 2007

Abstract
A gas development program was kicked off in 1998 with the objective of boosting gas production in excess of 1 billion scfd by 2001. The project included drilling 51 wells in Zone I, Zone II, and Units A & B limestone formations. Vertical cased and perforated completions were utilized in the more permeable Zone I while the tighter Zone II and Unit A & B intervals were completed horizontally with ~3000’ open hole lateral drains.
Historically, acid (HCL) stimulation has been routinely carried out after running the completion string. Assessing the added value of this practice was required as horizontal stimulations are inherently more complex and expensive when compared to vertical treatments. This complexity is compounded by recent environmental initiatives which target minimizing acid flowback and eliminating flaring in all field operations. The potential to compromise future horizontal hole access is also significantly greater if acid is not uniformly distributed across the lateral section. Use of "Non Damaging" fluids in addition to other drilling practices also help minimize effects causing near wellbore damage.
The assessment was carried on a number of wells selected according to specific criteria. Conventional coiled tubing acid placement techniques were used and all wells were production tested pre and post HCL acid stimulation. The primary conclusions drawn from this work were;Insignificant productivity improvement is realized in open hole horizontal wells.Considerable productivity improvement was realized in the vertically cased and perforated wells.
Based on these findings, only Zone I vertical wells will be acid stimulated.
Comparative Seismo-Stratigraphic Architecture of Two Cretaceous Carbonate Platform Sequences: Influence of Local Tectonics and Sea-Level Fluctuations on Development of Reservoir Architecture
Authors: Cortis A. L , Asyee W. H. , Borgomano J. , Foster K. A. , Godfrey S. , Harris K. , Lawati M. , Massaferro J. L. , van Konijnenburg J. H , Vizamora A. 
Published: December 2007

Abstract
The seismo-stratigraphy of two Cretaceous carbonate plat-forms was compared. Distinct seismic facies packages, with diagnostic geometries, reflect differing accommodation space evolution, depositional environments and reservoir architecture. These are used to guide static reservoir models and ultimately assist in field development planning.
The E-member of the Natih Formation of Oman represents parts of two, 3rd order sequences with a regional unconformity near the top. Seismic facies reflect changes in accommodation space and water energy. Parallel to sub-parallel loopsets at the base and top of the Natih E represent the transgressive phases of the sequences. Combinations of seismic geometries with mounded, clinoforming and planar loopsets in the Middle Natih-E represent highstand complexes. These probably developed over palaeo-topographic highs. Abrupt lateral truncations of parallel reflectors near the top of the Natih-E (E1-E2) are caused by incised channels - probably formed during lowstands near the end of Natih-E deposition. Reservoir is best developed in the mounded seismic facies, followed by the incised channel facies and finally the by the planar facies.
The Cogollo Group, Venezuela is divided into - from bottom to top - the Apon, Lisure and Maraca Formations. The Apon Formation, a thick, upward cleaning, transgressive to highstand system, forms complex loopsets with variable character. Planar seismic facies, diagnostic of laterally continuous grainstone sheets, are developed in areas with less accommodation space. Mounded and onlapping seismic facies occur across a regional hinge line. These delineate depositional bodies that probably developed in deeper water. The Lisure Formation comprises interbedded shale and limestone deposited in a low energy environment. These form a planar continuous loopset. The Maraca Formation forms part of a 3rd order transgressive system tract. It is the thinnest unit, but hosts the largest proportion of hydrocarbons. It forms a laterally continuous high-energy grainstone sheet, manifested as a continuous, single loop. Subtle changes in the loop reflect variations in reservoir quality.
Economic and Envionmental Impacts of using Natural Gas vs. Petroleum Products In Egypt (1981/82 – 1998/99)
Authors: Alnakeeb Hani , Ibrahim Adel , Kamal Osama 
Published: December 2007

Abstract
Egypt’s main energy resources are petroleum, natural gas, hydropower, and some limited quantities of coal. Also, Egypt enjoys good potential of renewable energy resources specially wind and solar energy. Crude oil and natural gas account for about 92% of total commercial energy consumption.
With the increasing reserves of natural gas, compared to those of crude oil, it become the petroleum sector’s policy to maximize the use of natural gas to supply the local energy needs in the different economic sectors.
A natural gas substitution policy has been adopted and implemented to promote the use of natural gas in electricity generation, industry, residential and commercial sectors. Within the same policy framework, the petroleum sector has taken the lead to use natural gas in transport sector. Natural gas has several advantages, economically and environmentally, which enhances its penetration in different energy consumption sectors.
This paper will focus on the economic and environmental advantages of using natural gas vs. petroleum products, at both sectoral and macro levels, showing how such substitution policy secured the petroleum energy supply for different economic sectors and contributing in sustainable development in Egypt.
Nitrogen Injection for Simultaneous Exploitation of Gas Cap
Authors: Tiwari Sanhita , Kumar M. Suresh 
Published: December 2007

Abstract
A compositional study has been carried out for evaluation of nitrogen injection in the large gas cap of a light oil reservoir (GS-4) as a low cost replacement gas. GS-4 is one of the major hydrocarbon bearing reservoirs in Gandhar field with oil in place of 6.37 MMt overlain by a large gas cap of 8.682 BCM. The gas reserves therefore represent a significant portion of the reservoir’s total economic value. The timing of production, from both the oil zone and the gas zone, is an important factor in optimum plan of exploitation for maximising the economic returns in addition to the goal of optimising oil recovery from this reservoir.
The existing exploitation scheme for this reservoir focuses mainly on the optimum exploitation of the oil reserves. This scheme restricts the exploitation of the large gas cap. The gas cap can be blown down only after the exploitation of oil zone. This paper discusses the strategy of early exploitation of rich gas cap gas and associated natural gas liquids by replacing it with low cost gas like nitrogen. Cryogenic air separation method can generate nitrogen in large volumes at a fraction of the cost of natural gas and thus provide large economic benefits. This strategy can advance the gas cap gas sales by 15–20 years ahead of the currently planned blowdown stage.
The paper presents the results of sectional study in GS-4 to evaluate the feasibility of nitrogen vis-à-vis lean gas injection. A detailed compositional study was carried out using a seven component equation of state (EOS) model. The paper discusses the key issues in fluid characterisation of GS-4 and its phase behaviour effects in contact with nitrogen. GS-4 gas cap presents production potential of around 1.5 MMm3/d for 10 years. The study indicates very attractive economic benefits for nitrogen injection as a replacement of gas cap gas.