bluuebunny/crossref_metadata_2025_split huggingface dataset:
Classification of PDC bits According to their Steerability
Authors: Menand S. , Sellami H. , Simon C. 
Published: December 2007

Abstract
With the emergence of rotary steerable systems, the technical issue concerning the bit design for a specific directional application has reappeared. Today, a bit must be specifically designed for use with a particular directional system: rotary bottom hole assembly (BHA), steerable mud motor or rotary steerable system (RSS). The reason is that the bit must have the ability to respond properly and rapidly to a side force applied by the steering system in order to initiate a deviation as requested. To do so, the bit must have a predetermined steerability compatible with the directional system in order to provide the optimum dog leg potential.
The new generation of directional drilling systems differentiates "pointing the bit" from "pushing the bit". As a consequence, the bit directional response is a key factor that operators and directional drillers need to know to make the good adaptation between the bit and the BHA. However at the moment, there is no standard method that can propose a way to classify bits according to their steerability and walking tendency.
Based on a comprehensive analysis of the directional behavior of polycrystalline diamond compact (PDC) bits (numerical simulation, pilot and field tests), a simple methodology has been developed in order to define and evaluate the steerability and the walking tendency of PDC bits. This methodology is used to classify the PDC bits defined with their IADC bit profile codes.
As the PDC bit steerability is mainly a function of the bit profile, the gage cutters and the gage pad, some design recommendations are given concerning these three parts. For each IADC bit profile code, the bit steerability and the walking tendency is estimated through some formulas linking only the heights and lengths of the cutting profile. Some guidelines are also given about the gage pad length and gage cutters characteristics in order to achieve improved steerability.
This simple method based on geometrical criteria enables to estimate quickly not only the PDC bit steerability, but also the maximum dog leg potential achievable by the PDC bit, when coupled with the steering system.
An Innovative Approach to Development Drilling in Deepwater Gulf of Mexico
Authors: Watson Pat , Kolstad Eric , Borstmayer Richard , Pope Tom , Reseigh Andy 
Published: December 2007

Abstract
Anadarko Petroleum's Marco Polo development is located in approximately 4,300 ft. of water in Green Canyon Block 608, in the central Gulf of Mexico (GOM). The discovery and appraisal wells were drilled in 2000, and the field will ultimately be produced using a tension leg platform (TLP).
The development drilling, which will be complete by 1st Quarter 2003, uses several innovative approaches to maximize project value. Some of the approaches challenge current industry trends and will be highlighted in this paper.
The Development and Application of Environmentally Acceptable Thermal Insulation Fluids
Authors: Dzialowski Andrew , Ullmann Holger , Sele Arne , Oosterkamp Ljiljana Djapic 
Published: December 2007

Abstract
Production from fields developed in deeper and colder waters requires that the hydrocarbons brought to the surface be at the highest possible temperature to eliminate asphaltenes, paraffins and hydrates from blocking a production line. Good insulation allows a less viscous fluid to be produced at higher rates, extend shut-in period and reduce stress during expansion and contraction of pipes. Ideally, the annular space between the riser and production line should be isolated with a special, low thermal conductivity fluid. Further, the insulation fluid must be environmentally acceptable to mitigate the effects of any spills or other unexpected events.
The recent development of a lightweight hybrid riser for a deepwater completion in North Sea required a thermal insulation fluid that was both cost effective and environmentally acceptable.
This paper describes a unique joint project to develop a lightweight riser and insulating fluid. The development included the building of a special test facility, which featured a 20-m long (60 ft) full size aluminum riser with electrically heated production pipe, which was filled with insulation fluid. The test piece was immersed into the sea for several months exposure.
The authors will detail several formulations, both mineral oil and water-base fluids including simple techniques to measure thermal conductivity, diffusivity and heat capacity. These data are compared to a specially developed computer model and field data from long-term exposure test. Other applications of the thermal fluid is drilling through permafrost and insulating transportation lines.
Summary of Results from a Joint Industry Study to Develop an Improved Methodology for Prediction of Geopressures for Drilling in Deep Water
Authors: Bridges James W. 
Published: December 2007

Abstract
This paper summarizes some results from a joint industry project organized through the Drilling Engineering Association to develop an improved methodology for pre-drill pore pressure and fracture gradient prediction for wells in deep water. The project known as DEA 119 was sponsored by Chevron and funded by a group of 21 organizations that included oil and gas operating companies, service companies and government organizations. Phase 1 of DEA 119 began in early 1999 and was completed in November 2001. Phase 2 began thereafter and is scheduled for completion in late 2003. This paper will provide an overview of the project and summarize some of the findings. Project activities ranged from industry surveys and in-depth reviews of various models and methods to detailed geopressure analysis of 100+ deep water Gulf of Mexico wells using a wide variety of approaches. Results from Phase 1 of the project were documented in a 300+ page best practice manual and a five day training course as well as a sizable database that includes analysis results and input data for the wells used in the project. Based on the consensus of participants, the project was limited to the Gulf of Mexico and geologically similar areas in other parts of the world. Virtually all the well data submitted by project participants was from the Gulf of Mexico. An argument can be made that the results are broadly applicable to geologically similar regimes in other parts of the world, i.e. deltaic basins with reservoirs in relatively young geologic strata that have undergone fairly rapid deposition. Phase 2 of the project is focused on further utilizing the database built in Phase 1 along with additional geologic and seismic data to construct geopressure models for several deepwater basins in the Gulf of Mexico and also to develop an improved methodolgy for fracture gradient prediction in deep water wells.
Plan for Surprises: Pore Pressure Challenges during the drilling of a Deepwater Exploration Well in mid-winter in Norway
Authors: Doyle Eamonn F. , Berry John R. , McCormack Niall J. 
Published: December 2007

Abstract
In the winter of 2001–2002 BP drilled the Havsule exploration well in 1495m of water offshore Mid-Norway. The efficient and safe drilling of the well was a major challenge due to a series of unknown factors including pore pressure. It was therefore necessary to plan and drill the well with a wide range of outcomes in mind and be prepared to adjust plans during drilling operations. With a particular focus on pore pressure, this paper describes how the well was planned and drilled to account for the uncertainties involved in drilling an exploration wildcat far out in the basin and a long way from any other well.
Some of the challenges were: Deepest water well so far in Norway.One of the worst winters in recent years.A gigantic submarine slide 8000 years ago that removed several hundred meters of sediment, increasing the uncertainty concerning pore pressure, fracture and overburden gradients.Uncertainty in the lithology.
During well operations there was a high focus on monitoring the pore pressure. Annular pressure and formation pressure were monitored as drilling progressed and pressure prediction models were continuously updated.
The results show that careful objective setting, planning, teamwork and implementation can help to achieve results even in difficult conditions with large uncertainties.
Closed Hole Circulation Drilling: Case Study of Drilling a High-Pressure Fractured Reservoir - Tengiz Field, Tengiz, Republic of Kazakhstan
Authors: Sweep M. N. , Bailey J. M. , Stone C. R. 
Published: December 2007

AbstractThe drilling of a sour, high-pressure fractured reservoir in the Tengiz field of Kazakhstan displayed complex and hazardous well control situations. While drilling the carbonate reservoir termed Unit 1, multiple fractures were encountered resulting in severe lost circulation followed by hydrocarbon influx into the well-bore.Severe and uncontrollable lost circulation in the target reservoir prompted the use of special practices and equipment; thereby enhancing the safety and efficiency in the development drilling of the field.A rotating control device (RCD) was employed to drill ahead blind (no fluid returns) by pumping a sacrificial fluid (water) down the drillpipe. Simultaneously, a pressurized mud-cap on the annulus with weighted oil based mud OBM controlled hydrocarbon influx. The overall process of pressurized mud-cap drilling will be described by the term Closed Hole Circulation Drilling (CHCD).The successful application of CHCD has resulted in Tengiz well T-7252 being the first well to completely penetrate Unit 1 where lost circulation could not be controlled by conventional methods. After all Unit 1 fractures had been penetrated, a liner was installed to isolate the fractures using the same CHCD well control procedures employed while drilling the interval.This technical paper will describe the process used to successfully plan, develop, and implement the CHCD technique in the Tengiz field.
Characterization of Blowout Behavior in Deepwater Environments
Authors: Adams Neal , Economides Michael J. 
Published: December 2007

Abstract
Offshore petroleum activities are likely to emerge as the next and clearly the most formidable technological challenge in the international petroleum industry. Both the size of the potential resource and the anticipated productivity of offshore oil and gas reservoirs will dwarf the behavior of even the most prolific presently on line petroleum resources. In accessing these reservoirs problems associated with on-shore or shallow offshore formations take a different hue.
Blowouts in water depths to 10,000 ft have certain potential ramifications not currently understood. Work has been done by several investigators to analyze blowout plume behavior, particularly with a view towards buoyancy and centerline plume wandering in the region immediately below sea level. To date, a more comprehensive reservoir-to-sea level study has yet to be undertaken and reported in the literature.
This paper reports on results from work to characterize blowout behavior in deepwater environments. The initial effort was to use reservoir and phase behavior modeling to determine mudline flow rates under worst-case conditions. MMS data from deepwater, Gulf of Mexico reservoirs was used to establish reasonable parameter boundaries. Normal and abnormal pressures were investigated, separate oil and gas blowouts were studied; wellbore diameters up to 14 inches were evaluated as some operators are currently contemplating using this bore size.
Results from the reservoir model were entered in plume modeling calculations prepared for this work. The model allows multiple crosscurrent studies as well as temperature modeling from the mudline to sea level. Again, separate oil and gas runs were made.
In some cases, these results followed intuitive expectations. Other scenarios rendered unanticipated findings. Specific conclusions include (1) identification of some reservoir and fluid systems that have little capacity to flow, even under an open flow scenario, (2) typical cross-current conditions do not seem to have a pronounced effect on the plume centerline at sea level and (3) oil blowouts have noticeably different characteristics than gas flows.
Well Control Procedures for Dual Gradient Drilling as Compared to Conventional Riser Drilling
Authors: Schubert J. J. , Juvkam-Wold H. C. , Choe J. 
Published: December 2007

Abstract
In order to meet the world's increasing demand for energy, petroleum producing companies must search for oil and gas in increasingly hostile environments. One area that shows great promise is in the deep water areas of the U.S. Gulf of Mexico. This is evidenced by increased lease sales and drilling activity that has occurred there within the last few years. As drilling moves into deeper waters, new technologies must be developed for safe and successful operations.
Beginning around 1996 four projects were begun to develop dual gradient drilling, DGD, technology for use in water depths greater than 5000 ft. The four projects are Shell Oil Company's project1, the SubSea MudLift Drilling Joint Industry Project2, SMD, the Deep Vision project3, and Maurer Technology's Hollow Glass Spheres project4. Several publications have discussed the advantages that dual gradient drilling technology has over conventional deepwater drilling in the ultra-deepwaters.5,6,7
Although the advantages of the dual gradient projects are well documented, there has been little published on one of the major concerns expressed by all four projects. That is, how will well control differ for dual gradient drilling as compared to conventional riser drilling?6,8,9 This paper reports on a comparison of the well control aspects of dual gradient drilling to those of conventional riser drilling. It is based upon the work that the authors performed as part of the SMD project.
Understanding Formation (In)Stability During Cementing
Authors: Heathman J. , Tare U. , Ravi K. 
Published: December 2007

AbstractManaging formation (in)stability should be an integral part of well construction from drilling through cementing and completion operations. Formation (in)stability while drilling has been recognized and is an ongoing study in the petroleum industry. Most of the emphasis in these studies has addressed the interactions between drilling fluids and formations, as well as, the geomechanical aspects. However, if the wellbore is stable at the end of the drilling phase, but the cement and spacer properties are not optimized accordingly, the formation could be destabilized during cementing. Such an event could negate much of the prior effort toward controlling instability. Destabilization could adversely impact the well construction and overall field development throughout the well's lifecycle.As the rock material is removed and replaced by a drilling fluid and subsequently displaced by cementing fluids (spacer and cement slurry), stability of the wellbore should be ensured by applying an adequate net radial support to the formation. The borehole pressure exerted by these fluids can counteract the near-wellbore effective stress concentration created while drilling. If the radial support applied to the formation is inadequate, the stress concentration can exceed the formation compressive strength, leading to borehole collapse. On the other hand, excessive borehole pressure can lead to lost circulation problems if the near-wellbore tangential (circumferential) stress and the formation tensile strength are exceeded. As the formation is exposed to drilling and cementing fluids, the near-wellbore effective stress concentration is altered because of the formation fluid's physicochemical interaction. Such alteration of the effective stresses and formation properties can result in time-dependent stability problems.
Washout of Cr(III)-Acetate-HPAM Gels from Fractures
Authors: Seright R. S. 
Published: December 2007

Abstract
This paper investigates washout of mature Cr(III)-acetate-HPAM gels from fractures. After gel placement, the pressure gradient for gel washout during brine or oil flow was similar to the pressure gradient observed during gel placement. The mechanism of gel failure involved the displacement of relatively mobile gel from wormholes. Generally, only a small fraction of the gel (&lt;5%) was displaced during the washout process. Resistance to washout can be increased by injecting a more concentrated gel. However, this approach exhibits significantly higher pressure gradients during gel placement.
The presence of a constriction in a fracture inhibited gel washout during the first pulse of brine flow after gel placement. However, during subsequent brine flow, gel erosion occurred upstream of the constriction to the same extent as downstream. The extrusion, leakoff, and washout behavior in fractures in strongly oil-wet polyethylene cores were similar to those in strongly water-wet Berea sandstone.
Gel washout can be reduced by controlling gel placement rate. A Cr(III)-acetate-HPAM gel placed in a 0.04-in. wide fracture at 826 ft/d was about five times more resistant to washout than a gel placed at 4,130 ft/d. Gel washout can also be reduced using secondary crosslinking reactions. Post-placement reaction with Cr(III) acetate increased resistance to washout for a resorcinol-formaldehyde-HPAM gel by a factor from two to three.
During steady state flow after first breaching the gel, a Cr(III)-acetate-HPAM gel reduced permeability to water (within the fracture) moderately more (2.5 to 4.7 times) than that to oil. Disproportionate permeability reduction in fractures was most evident at low flow rates.
Polymer Design for Relative Permeability Modification Treatments at High Temperature
Authors: Chiappa Luisa , Andrei Maria , Lockhart Thomas P. , Maddinelli Giuseppe , Burrafato Giovanni , Pitoni Enzo 
Published: December 2007

Abstract
Previous studies have shown that cationic polyacrylamides are particularly effective agents for selectively reducing the permeability of treated rock to water. This ability depends on several factors, but a key role is played by the cationic functionality, which anchors the polymer to the rock. It is shown here that the applicability of these treatments to higher temperature is severly limited by the tendency of the cationic group (above 50°C) and the polyacrylamide backbone (above 70°C) to undergo hydrolysis. A general chemical strategy is outlined for overcoming these two effects, and two new families of cationic, high molecular weight polyacrylamides are reported which display excellent stability to 70°C and 100°C, respectively. These polymers demonstrate excellent relative permeability modification properties in laboratory tests, a result which has been confirmed in the field in a dry gas well treatment.
Effect of Flow Rate on Disproportionate Permeability Reduction
Authors: Ganguly S. , Willhite G. P. , Green D. W. , McCool C. S. 
Published: December 2007

Abstract
Disproportionate permeability reduction (DPR), in which water permeability is reduced to a much greater extent than oil permeability, has been observed in a number of polymer gel systems. Although several different mechanisms have been proposed, no one mechanism has been generally accepted. In the study reported here, the focus was on the effect of flow rate on DPR by varying the pressure gradient. Polyacrylamide-chromium acetate solutions were allowed to gel in Berea sandstone rocks. Flow channels were then developed by dehydration of the gels by flowing oil or water at a specified pressure gradient. After dehydration was complete, water and oil displacements were successively conducted over a wide range of pressure gradients, always maintaining the pressure gradient at a value equal to or less than the pressure gradient used for dehydration. Oil saturation of the rock was monitored from analysis of the effluent and the use of a tracer in the oil phase. The saturation profiles in some of the rocks were obtained from microwave scans at various stages of the experiment. Permeabilities and residual resistance factors at residual saturations were calculated and reported as a function of pressure gradient. RRF values for brine decreased by an order of magnitude upon increase in pressure gradient. RRF values for oil, however, decreased to a much less degree over the same increase of pressure gradient. At high pressure gradients, DPR diminished in one set of experiments. The variation of permeability with pressure gradient demonstrates that the gel structure is elastic and deforms when pressure gradient changes. The results were compared to literature data and it was found that rate effects were generally present in previously reported work.
Starch-Lubricant Compositions for Improved Lubricity and Fluid Loss in Water-Based Drilling Muds
Authors: Sifferman Thomas R. , Muijs Herman M. , Fanta George F. , Felker Frederick C. , Erhan Selim M. 
Published: December 2007

Abstract
Development of water-based mud systems that approach the performance of oil-based muds is an ongoing effort. Starch-lubricant compositions were developed as environmentally safe, non-toxic, stable dispersions in water-based drilling muds. Starch-lubricant compositions were prepared by jet cooking mixtures of water, starch, and lubricant to produce aqueous starch dispersions containing suspended lubricant droplets 1-10 microns in diameter. These droplets do not separate or coalesce. The dispersions were drum dried and milled to dry, non-oily powders containing 28% lubricant by weight.
These dry powders were then tested at 5 lb/barrel in laboratory-prepared lignosulfonate drilling muds. Various commercial olefins, esters and/or polybutenes were evaluated as lubricants. Standard laboratory tests indicated that starch-lubricant compositions lowered both API and HTHP fluid loss values. More importantly, coefficient of friction values were 12-25% of the untreated base mud and were similar to the average values for oil-based muds. Muds formulated with starch-lubricant compositions usually contained only 0.5% lubricant (v/v), yet performed better than a typical field mud control containing 3% lubricant (v/v).
These exceptionally good results with one-sixth the amount of a typical lubricant suggest that the size and distribution of lubricant droplets achieved in these systems may enhance lubricant efficiency. Therefore, further investigation of such formulations is warranted, including a field test to evaluate the advantages of this newly-patented technology.