bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strategy to Reach Deepwater
Authors: Cruz J. Nieto , Rojas G. Santiago , Hernandez A. Gomez 
Published: December 2007

Abstract
This paper shows how Pemex is looking the future to exploit reserves located in deepwater. Southwest Marine Region has increased its exploratory activities beyond the common water depths with high expectations to start up an important development of potential reserves laying in a huge area of the Gulf of Mexico. It is also analyzed some concepts for deepwater applications and regulations stated by Mexican Government to make operations in this area. Pemex has taken advantage of producing in shallow waters for a long time. However, top management of Pemex is aware of assuming the challenge of taking over in new horizons. As a result, it has been planned to integrate a workteam which includes several specialities focused in a long term training on developing deepwater fields.

Introduction
Recently the oil world has focused its attention on deepwater developments and every time more countries have been entering to the scenary. Countries like Indonesia and Egypt have been making important finds in deepwater acreage, Israel is also going into deepwater with a well drilled in 2555 ft water depth in the Mediterranean Sea, Malaysia has drilled its first exploration well in 2,417 ft water depth. Other countries are trying for deepwater plays, Turkey with Limankoy-1 well in 2,788 ft water depth water, Australia is planning to drill three deep water wells over 4,000 water depth. New Zealand with Waka Nui-1 well, in 4,812 ft water depth. Norway have tried with un unsuccessful well in the Gjallarryggen area in 4,400 ft water depth1. The oil world is moving around deepwater, consequently, technology is evolving, day after day.
Surprising projects have grown up in a joint ventures environment like some state companies are doing in their countries. What is important to do in Pemex to keep up with companies actually working in deepwater is to engage human, material and monetary resources in such ambitious projects like Deepstar, kicked off by Texaco2 in 1992 with the mission of encouraging an industry worldwide cooperative effort focused on developing economically viable, fit-for-purpose deepwater technology. Undoubtedly this mission is supported by a great vision. After having runned four phases, benefits have significantly been increased while more operators are being added to the list. To date 23 oil companies are participating and about 45vendor companies contribute in Regulatory, Flow Assurance, Subsea & Equipment, Vessel, Mooring & Riser, Drilling and Completion, Administration, Reservoir Engineering, and Met Ocean, with cooperative efforts further successful deepwater technologies are expected.
What about Pemex E&P?, how is Pemex E&P doing to keep up with this accelerated worldwide change?. Is it prepared to jump over those spectacular projects in an environment regulated by governmental policies?. Technical gap between traditional ways of working in Pemex and those runned by successful companies working worldwide is huge. There is a big hill to climb to reach the top, so, Pemex has to set the pace to overcome it.
In-Situ Reactive System Stops Lost Circulation and Underground Flow Problems in Several Southern Mexico Wells
Authors: Rueda Francisco , Bonifacio Raúl 
Published: December 2007

Abstract
Over the years, operators have used many different techniques in the attempt to solve lost circulation and underground flow problems. Recently, polymer additives and new sealing methods have been used to combat such problems. However, these additives and techniques require extensive preparation time because they must be incorporated into the mud system. While some of these systems can solve minor problems, most cannot solve severe problems associated with large underground flows, fractures, vugs, or channels in weak formations.
A new, reactive, water-based lost-circulation material (LCM) has been successful in treating lost circulation and underground flows. The success of jobs performed with this material depends on the job technique used and the material's reaction with the drilling mud. This LCM is designed to react with water-and oil-based muds as well as environmental muds. It can help stop loss of drilling and completion fluids. Additionally, it can help increase or restore the integrity of weak formations, extend casing-shoe points, and eliminate intermediate casing strings.
This LCM reacts with drilling mud to create a barrier at the face of the lost-circulation zone. The LCM develops a moldable consistency within approximately 30 seconds of reacting with the mud and forms a ductile, nonbrittle bridge against the opening of the fluid-loss zone. This bridge can conform to wellbore or near-wellbore fractures as they change shape be-cause it only minimally penetrates the formation matrix or fracture. In laboratory tests, the material penetrated samples less than 164 in.
This LCM has been successful in the Rio Nuevo, Sen, Fortuna Nacional, and Luna fields in southern Mexico, preventing the operator from having to plug and abandon the wells. Two case histories are presented in this paper.
Design Index: A Systematic Method of PDC Drill-Bit Selection
Authors: O'Hare Jim , Aigbekaen Osarumwense O. A. 
Published: December 2007

Abstract
Advances in drillbit technology have resulted in suppliers adding a seemingly endless array of features to improve bit performance. There is little standardization between bit designs, so drilling engineers and supervisors are faced with difficult choices when selecting drillbits. This paper outlines the development of a systematic method of PDC bit selection. The system is not an ‘expert system’, but a simple methodology that can be readily adapted by engineers to suit their conditions. A basic geological model is developed for each hole section. Formation strength and drillability are calculated from porosity, sonic travel time, matrix rock velocity, degree of compaction, abrasiveness and hole cleaning requirements. The geological model can be adapted to any area by specifying the main rock types and their percentages in the section to be drilled. If not known, typical properties can be obtained from tables included. Individual well profiles are specified by the percentages of build, drop and holding tangent, and also dogleg severity. Combining the geological model and well profile enables a set of ‘ideal’ bit characteristics to be generated. This ideal bit design is compared with the drillbits proposed by vendors. These are ranked by indices for design, performance and economics. [The Design Index takes into account bit characteristics such as the bit profile, number of blades and cutters, cutter size, junk slot area and backrake.] The selection is based on the bit that provides the closest match to the ‘ideal’ design. The methodology has been geared to fixed cutter PDC bits but is being expanded to include roller cone bits. Although the system was originally developed for extended reach and horizontal wells, it can be applied equally to any type of well.
The Mounds Drill-Cuttings Injection Field Experiment: Final Results and Conclusions
Authors: Moschovidis Zissis , Steiger Ronald , Peterson Richard , Warpinski Norm , Wright Chris , Chesney Ed , Hagan Joe , Abou-Sayed Ahmed , Keck Richard , Frankl Matt , Fleming Carole , Wolhart Steve , McDaniel Buddy , Sinor Allen , Ottesen Steinar , Miller Lynn , Beecher Reid , Dudley John , Zinno Dick , Akhmedov Oktay 
Published: December 2007

Abstract
This paper summarizes the results obtained from a comprehensive, joint-industry field experiment designed to improve the understanding of the mechanics and modeling of the processes involved in the downhole injection of drill cuttings. The project was executed in three phases: drilling of an injection well and two observation wells (Phase 1); conducting more than 20 intermittent cuttings-slurry injections into each of two disposal formations while imaging the created fractures with surface and downhole tiltmeters and downhole accelerometers (Phase 2); and verifying the imaged fracture geometry with comprehensive deviated-well (4) coring and logging programs through the hydraulically fractured intervals (Phase 3).
Drill cuttings disposal by downhole injection is an economic and environmentally friendly solution for oil and gas operations under zero-discharge requirements. Disposal injections have been applied in several areas around the world and at significant depths where they will not interfere with surface and subsurface potable water sources. The critical issue associated with this technology is the assurance that the cuttings are permanently and safely isolated in a cost-effective manner.
The paper presents results that show that intermittent injections (allowing the fracture to close between injections) create multiple fractures within a disposal domain of limited extent. The paper also includes the conclusions of the project and an operational approach to promote the creation of a cuttings disposal domain. The approach introduces fundamental changes in the design of disposal injections, which until recently was based upon the design assumption that a large, single storage fracture was created by cuttings injections.
Predrill Pore Pressure Prediction Using Seismic Data
Authors: Sayers C. M. , Johnson G. M. , Denyer G. 
Published: December 2007

Abstract
An accurate knowledge of formation pore pressure is a key requirement for the safe and economic drilling of deepwater wells. A pre-drill estimate of pore pressure can be obtained from seismic velocities using a velocity to pore pressure transform. However, the velocities used are often not ideal. Seismic velocities used during seismic processing are designed to optimize the stack/migration result, with local fluctuations being smoothed out and the velocity sampling interval usually being too coarse for accurate pore pressure prediction. Various methods of determining seismic interval velocities from prestack seismic data are compared, and a velocity analysis approach suitable for pore pressure prediction is recommended. This is aimed at producing a pre-drill pore pressure cube from 3D seismic data, and uses seismic tomography to obtain an accurate velocity model. Seismic velocities obtained by conventional methods average the velocity over the seismic aperture and are therefore not suitable for pore pressure prediction in the presence of lateral variations, as may arise from the presence of dipping structures, lithology variations, salt layers of various thickness, fault blocks or variations in compaction and pore pressure. Reflection tomography gives improved spatial resolution of the seismic velocity field and thus allows a more reliable pre-drill pore pressure cube to be obtained. The method is used to predict pore pressure for a deep water Gulf of Mexico case study.
Formation Characterization of A Horizontal Well While Drilling: An On-Site Tool
Authors: Samuel G. Robello , Miska Stefan 
Published: December 2007

Abstract
This paper describes a method of predicting formation pore pressure and permeability in a horizontal well during the drilling phase of a well development. Dependable and more accurate information about reservoir parameters such as permeability, pore pressure are indispensable for taking proper well completion decisions at a stage when the formation damage is minimal. In this study, a technique is described which can be used as an onsite tool for the evaluation of formation properties for horizontal wells. Method of analysis is based upon the buildup data collected during a test conducted at various stages of the wellbore penetration in the horizontal section while drilling. Modified well testing theory pertaining to horizontal wells is used for the interpretation of the test results. Examples of using simulated data are provided to demonstrate the practical application of the method. These examples using the proposed approach elaborated in this paper illustrate its practicability and the ease of usage as an onsite tool.
Optimisation of Well Economics By Application of Expandable Tubular Technology
Authors: Owoeye Oladele O. , Aihevba 'Leste. O. , Hartmann R. A. , Ogoke V. C. 
Published: December 2007

Abstract
The installation of over 1000 ft of Expandable Sand Screen in a horizontal well has presented the most technically challenging application of the Expandable Tubular Technology (ETT) to date. With increasing emphasis on well economics in the current uncertain oil price regime, the optimization of well configurations, reduction of well construction costs, increase in well productivity and reduction in life cycle well maintenance expenses becomes critical to achieving business success.
The paper presents the deployment of ETT, as an Expandable Sand Screen, in an application that impacts on all three economic factors; well costs, well productivity and life cycle well operating expenditure; positively in a single installation. It addresses numerous drilling, completion and productivity challenges to deliver the optimum drain hole (increased productivity) from a slimmer well (reduced well construction costs) with down-hole equipment that needs minimal re-entries and remedies, (reduced operating expenditure).
With a vision to improve production in SPDC by 60% in the short term and by over 200% (to 2.5 MMbopd) by the year 2010, most new wells are completed horizontally with minimum potentials of 3000 bopd. The application of ESS in horizontal well was a novel challenge, with history of only four installations, the most challenging being the deployment of some 240ft of ESS in a 61° deviated well.
This paper reviews the economic and technical justification for the deployment of the longest and first horizontal application of ESS in the World in Imo River 63 (Ex-SMTQ-5). It emphasizes on the planning, project management, risk assessment, and critical engineering considerations applied to assess the technical feasibility of deploying ESS in a horizontal well.
The paper concludes with the highlights of the execution phase, ESS handling procedure, success, problems and recommendations from the field trial.
Development and Testing of Insulated Drillpipe
Authors: Finger J. T. , Jacobson R. D. , Champness A. T. 
Published: December 2007

Abstract
The Geothermal Research Department at Sandia National Laboratories, in collaboration with Drill Cool Systems, Inc., has worked to develop and test insulated drillpipe (IDP). IDP will allow much cooler drilling fluid to reach the bottom of the hole, making possible the use of downhole motors, electronics, and steering tools that are now unusable in high-temperature formations. Other advantages of cooler fluid include reduced degradation of drilling fluid, longer bit life, and reduced corrosion rates.
The paper describes the theoretical background, laboratory testing, and field testing of IDP. Structural and thermal laboratory testing procedures and results are described. Results are given for a field test in a geothermal well, in which circulating temperatures in IDP are compared with those in conventional drillpipe (CDP) at different flow rates. A brief description of the software used to model wellbore temperature and to calculate sensitivity to IDP design differences is included, along with a comparison of calculated and measured wellbore temperatures in the field test. Analysis of mixed (IDP and CDP) drill strings and discussion of where IDP should be placed in a mixed string are presented.
Lateral Buckling of Pipe with Connectors in Horizontal Wells
Authors: Mitchell R. F. 
Published: December 2007

Abstract
The effect of connectors on pipe buckling has only recently received attention. For non-buckled pipe, Lubinski analyzed the effect of connectors on pipe in tension in a curved borehole and Paslay and Cernocky extended this analysis to pipe in compression. The first analysis of buckled pipe with connectors was done by Mitchell, who developed a three dimensional analysis of helical buckling. These papers indicate that bending stresses are greater due to connector stand-off.
Laterally buckled pipe with connectors is analyzed for the first time in this paper. It presents an analytic solution of the beam-column equations in three-dimensions in a horizontal wellbore with pipe weight. Pipe deflections, contact loads, and bending stresses are determined with explicit formulas. Sag between connectors is calculated so that pipe body contact with the wellbore between connectors can be determined.
Applications include the analysis of bottom hole assemblies, drill pipe, casing, and tubing. The solutions are simple formulas that are suitable for hand calculations.
Emergency Generator Operational Logic for Dynamically Positioned Drilling Rigs working in Ultra-deep Water
Authors: Rankin David , Padel Jacques , Morvan Pierre 
Published: December 2007

Abstract
A typical semisubmersible drilling rig working in water depths of 2000 ft moors using anchors, with thruster assistance to position itself over the work area. Rigs working in deeper water must use dynamic positioning with thrusters only. As the thrusters are electrically powered, any electrical blackout would cause the vessel to drift off station. This emergency situation would be compounded if the drillstring riser were still attached; drilling activity would terminate as the uncontrolled vessel moves away from the wellhead. This incident alone could cost millions of US dollars, with secondary damage possible.
A new rig is available that can work in 8500 ft of water and still remain on station within a specified radius around a given point in defined environmental conditions of wind, current and seastate. Main power generation is provided by six 4400 kW main generators in the pontoons, a location for the main generation that is unique to Sedco Express rig design and is covered by patent application. A seventh main generator on the deck is considered both as an emergency generator and as a service-assist unit under certain operational conditions.
The rig has two service transformers on deck and a third emergency transformer of the same rating topsides, giving significant advantages in the case of service mode failure. Any loss of power to the main high-voltage switchboards initiates a programmable logic controller. The precoded logic opens or closes circuit breakers, immediately switching the topside generator to emergency status to feed the low-voltage emergency switchboard via the emergency transformer, restarting the main generators to recover from the blackout.
Therefore, in effect, no power blackout occurs.
A typical emergency generator run-up time is about 45 seconds, plus human intervention time. On the new rig, approximately 60 seconds are gained restarting operations after a blackout situation occurs as a result of environmental conditions.
Wired BHA Applications in Underbalanced Coiled Tubing Drilling
Authors: Tinkham Scott K. , Meek Dale E. , Staal Timo W. 
Published: December 2007

Abstract
Underbalanced directional drilling with coiled tubing is emerging as an instrumental technique for accessing new and bypassed reserves while enhancing overall reservoir recovery since, unlike jointed-pipe operations, circulation does not have to be interrupted every 30 feet to make connections. Coiled tubing drilling (CTD) thus offers the potential to achieve genuine steady state underbalanced conditions resulting in the elimination of formation damage, lost circulation and differential sticking. One of the enabling technologies assisting the growth of underbalanced directional CTD is the wireline-steerable bottom hole assembly (BHA). In contrast to conventional mud pulse telemetry systems, these purpose-built wired BHAs have been designed to accommodate efficient, continuously underbalanced drilling operations while also providing an opportunity for reservoir evaluation while drilling.
The paper details the operational results for several underbalanced and low-head CTD projects involving an integrated wireline-steerable BHA. The most recent wells were completed in the North Sea, Canada and United States in 1999. Topics discussed include equipment performance, nitrified fluids, wellbore stability, well results and learning points. An analysis of time-based underbalanced CTD data is also presented.
Diffusion Osmosis-An Unrecognized Cause of Shale Instability
Authors: Simpson J. P. , Dearing H. L. 
Published: December 2007

Abstract
Problems encountered while drilling shale formations are a major factor in the cost of oil and gas wells. A principal cause of the problems has been shown to be the transfer of water and ions from water-based drilling fluids to shale formations. Prior studies have documented two driving forces involved in such transfer. One is the hydraulic pressure differential between the drilling fluid and shale pore fluid. A second is a chemical osmotic force dependent upon the difference between the water activity (vapor pressure) of the drilling fluid and that of the shale pore fluid under downhole conditions. Generally unrecognized is another driving force, diffusion osmosis, which is determined by the difference in concentrations of the solutes in the drilling fluid and shale pore fluid. Diffusion osmosis results in transfer of solutes and associated water from higher to lower concentration for each species, opposite to the flow of water in chemical osmosis. If the diffusion osmotic force exceeds the chemical osmotic force, invasion of ions and water can increase the pore pressure and water content of the shale near the borehole surface. Additionally, the invading ions can cause cation exchange reactions that alter the clay structure in the shale. All of these effects tend to destabilize the shale.
Destabilizing ionic reactions within a shale can be minimized if a suitable nonionic polyol (such as methyl glucoside) is used to reduce the activity of a fresh-water drilling fluid. In certain situations the addition of salt to such a fresh-water drilling fluid to obtain further reduction of water activity can cause an increase in the diffusion osmotic force that offsets some, or all, of the desired increase in chemical osmotic force. This now is recognized to have probably been a factor when sodium chloride was included in the formulation of a methyl glucoside drilling fluid used with moderate success for drilling in the Gulf of Mexico.
Chemical osmotic effectiveness can be improved by emulsification of a non-aqueous phase in the drilling fluid. A fresh-water drilling fluid containing methyl glucoside for activity control and emulsified pentaerythritol oleate prevented hydration and maintained stability of Pleistocene shale from the Gulf of Mexico. Drill cuttings from such a drilling fluid should be environmentally acceptable for discharge at offshore or land locations.
Drilling More Stable Wells Faster and Cheaper with PDC Bits and Water Based Muds
Authors: van Oort Eric , Bland Ronald , Pessier Rolf 
Published: December 2007

AbstractROP enhancer chemistry for water-based muds combined with polished cutter PDC (Polycrystalline Diamond Compact) bit technology is shown to: 1) increase penetration rates and lower costs drilling high pressured shales by reducing bit balling and improving drilling efficiency and 2) improve borehole stability by reducing exposure time and reducing near wellbore fracturing which minimizes pore pressure elevation and loss of borehole integrity. Laboratory drilling simulator and pore pressure transmission results, a case history, caliper logs and summary economics from 16 offshore wells are presented documenting the effectiveness of this technology.