bluuebunny/crossref_metadata_2025_split huggingface dataset:
World Class Drilling in the Gulf of Thailand: North Pailin Project
Authors: Yodinlom Wiwat , Luckanakul Nat , Tanamaitreejitt Pichai 
Published: December 2007

Abstract
The North Pailin field, located in the Gulf of Thailand (GOT) had been evaluated during 1996–1997 with 15 delineation wells. Risked gas resources of 1,280 BCF (1 January 2002) will be fully developed with a Central Processing Platform (CPP) and a total of 357 development wells on 31 wellhead platforms (WP). However, thanks to a flexible performance-oriented operational philosophy, Unocal Thailand put North Pailin development on a fast track, aggressive timeline that moved the start-up project from well plan to cash flow within 9 months.
Each well of the initial first four-platform drilling program was highly deviated and followed a 3-D design in three sections: 11–3/4", 8–1/2" and 6–1/8". During this drilling campaign, many world class drilling records were achieved: In February 2002, North Pailin A-05 3D-well was directionally drilled from spud (325-ft mud line) to 11,388 feet TD in 1.9 days at $49.6 per foot.The 12-well program on North Pailin-A was completed within 34.42 days, 115,103 feet were drilled by average 4,387 SFPD at $64 per foot.For the entire four-platform, four rigs had drilled 618,786 feet (117 miles) out of 55 wells in the first quarter of 2002, at an average cost of $850K per well or $76 per foot.Together with those records, 307,140 man-hours were also achieved safely without any lost time incidents.
The records achieved on the North Pailin make it the most efficiently drilled development program so far in the GOT. A brief background of the North Pailin will be presented. However, the main focus is to highlight the key performance statistics and offers insights into the success of the North Pailin drilling campaigns.
Drilling 3D wells in Western Siberia
Authors: Matevosov Andrei , Iskander Diyashef , Dupuis Dominique , Baradat Yves 
Published: December 2007

Abstract
In order to improve the development of a field in Western Siberia, Sibneft elects to drill 3D wells (5000 MD) with long horizontal drain (more than 1200m). Due to geographical conditions prevailing in Siberia those wells are drilled from a cluster. In order to drill those wells a heavy land drilling rig (3000hp) from Pride Forasol, well services from Halliburton, Schlumberger and Baker groups were mobilized.
How Probabilistic Methods Were Used to Generate Accurate Campaign Costs for Enterprise's Bijupirá & Salema Development
Authors: Zoller S. L. , Graulier J. -R. , Paterson A. W. 
Published: December 2007

Abstract
Well construction costs were critical to the overall commerciality of Enterprise Oil's Bijupirá & Salema development. Enterprise's well engineering team opted for a probabilistic approach to cost estimating so as to account for the inherent risks in the well construction process.
Peak's P1® process was used to generate probabilistic time and cost estimates for each of the operational phases, however a new system was required to generate a probabilistic time and cost estimate for the whole development campaign. Summing the individual phase estimates would not provide a statistically valid overall estimate and learning curve and correlation effects also had to be accounted for. Peak developed the C1 system to use the probability curves output by P1® to generate a probabilistic time and cost estimate for the whole development campaign. The C1 system provided the necessary quality of data for Enterprise to make decisions on project viability.
Use of Pressure Gauges in Liner Running Strings during Liner Cementing Operations
Authors: Brehme J. , Bain A. D. , Valencia A. 
Published: December 2007

AbstractWith surface measurements alone, liner cementing operations are difficult to interpret because of the dampening effects of the mud and greater overlaying pressure events such as cement free fall. In April 2001, an operator in the North Sea started to use downhole memory pressure gauges in the liner running string to gather pressure data for evaluation of liner equipment performance and cement placement. The collected data has shown downhole pressure effects that have not been seen with surface pressure measurements. This data also allows comparison of actual and simulated downhole pressure, which can improve cement job simulations.
Advances in Tieback Cementing
Authors: MacEachern Douglas P. , Algu Dave R. , Cowan Mike , Harris Kirk , Snell Eric 
Published: December 2007

Abstract
New cementing technologies and techniques have been applied to the challenging task of cementing tiebacks for long-term integrity. Cement sheath stress analysis, reverse cementing, ductile cements, and delayed-gel slurries are among the technical advances in tieback cementing that have been applied in the Gulf of Mexico. This paper outlines the reasons and methods for cementing tiebacks, and details the most recent technologies.
Selection of Foamed Cement for HPHT Gas Well Proves Effective for Zonal Isolation—Case History
Authors: Pine Michael , Hunter Liz , Mutch John , Adam John , Griffith James E. 
Published: December 2007

Abstract
This paper describes the reasons for and execution of a foamed-cement job to provide zonal isolation for a high-pressure, high-temperature (HPHT) sidetrack wellbore. Because adjacent wells cemented with non-nitrified, HPHT slurry designs showed marginal success in achieving zonal isolation, foamed cement was selected as the most effective means to achieve the following objectives in the case history well: Prevention of cement-sheath crackingPrevention of annular gas pressure over the life of the wellHigh mud displacementNo free-water or gas channel developmentLow slurry fluid loss
The benefits of foamed cement compared to non-nitrified cement as they relate to these objectives are explained in the body of the paper. Comparison of the new well to the existing, conventionally cemented wells indicates that foamed cement can be a more effective means of providing zonal isolation than non-nitrified, HPHT-designed cements.
The following sections outline the grounds for choosing foamed cement and the steps taken to execute the foamed-cementing operation. Included are recommended practices for prejob analysis and planning, job execution, and post-job evaluation.
Real-Time Cement Expansion/Shrinkage Testing Under Downhole Conditions for Enhanced Annular Isolation
Authors: Goboncan Virgilio C. , Dillenbeck Robert L. 
Published: December 2007

Abstract
Ongoing problems with sustained annular gas pressure on producing wells wordwide is a prime indicator that more work is needed in understanding how cement system design can impact long-term annular isolation. One important area is the relative expansion or shrinkage of cement systems as they hydrate in the annulus of a well.
Most Portland cement systems undergo chemical and bulk shrinkage as they set. A number of chemical materials have been developed that can be added to cementing systems to overcome this shrinkage, and in some cases, even impart a degree of expansion. However, the process whereby the degree of shrinkage or expansion is measured has almost universally been some type of a single point test, performed at ambient conditions. This is typically the case even if the cement sample was first hydrated under downhole conditions.
The authors detail new methodology and test equipment that allows for the tracking of cement shrinkage and/or expansion real-time, under downhole conditions of pressure and temperature. The system allows for the application of curing pressures in either an aqueous or non-aqueous environment. Data acquisition is totally computerized and can be maintained for whatever time interval is required, without exposing the hydrating cement to surface conditions. With this new technology, the authors will detail how cement expansion and shrinkage can be significantly different under downhole conditions of pressure and temperature than when measured at ambient conditions. It has also been observed by the authors that cement expansion or shrinkage is a dynamic process that may take many hours or even days before any significant degree of volumetric stability is achieved.
Finally, a successful field application of the new testing methodology will be presented as validation for the transfer of this new technology from the laboratory to the real world of oil and gas well cementing.
Gyrostab Project : The Missing Link Azimuth and Inclination Mastered with New Principles for Standard Rotary BHAs.
Authors: Genevois Jean-Michel , Boulet Jean , Simon Christophe , Reullon Christophe 
Published: December 2007

Abstract
Trajectory control in directional wells essentially requires control of only two parameters: well inclination and well azimuth. However, always tighter economic constraints and the increasing complexity of well trajectories keep setting higher challenges that demand purpose-designed and cost-efficient solutions.
The standard rotary drilling tools first used for directional drilling gave poor trajectory control. The subsequent addition of Variable Gauge Stabilizers (VGS) addressed only one side of the problem: control of inclination. Both inclination and azimuth were then mastered with Steerable Motor technology, which rapidly gained supremacy. However, there has been discontent with Down Hole Motors (DHM) for a variety of problems ranging from Rate Of Penetration (ROP), sliding mode, friction and lost-in-hole incidents to well tortuosity and hole cleaning. Jumping to rapid conclusions, one might thus think that that motors will soon be replaced by Rotary Steerable Systems (RSS).
This evolution of directional drilling techniques has led to the development of more and more sophisticated tools integrating electric and/or hydraulic power systems and loads of "embarked" electronics. The related expenditures have driven service costs to levels that are very often prohibitive for standard drilling programs and/or environments.
This paper introduces an innovative technical solution that makes it possible to control both azimuth and inclination using standard rotary Bottom Hole Assemblies (BHAs). It is based on a patented concept permitting command of Bit & BHA walking tendencies through downhole friction management at the level of a "strategic" string stabilizer.
On the basis of this concept, a joint industry project led by TotalFinaElf has successfully designed, built and field-tested a first prototype - the "Gyrostab". This missing link in the evolution of directional drilling announces the birth of a new generation of standard rotary drilling tools.
Development and Application of a Large-Hole Rotary Steerable System: Accelerating New Technology Introduction through Successful Collaboration
Authors: Armagost W. K. , Pafitis Demos , Wernig Marcus 
Published: December 2007

Abstract
This paper describes the successful introduction and application of a rotary steerable system for large hole sizes (17.5 and 18.25-inch.). The development of the large hole rotary steerable capability was seen to be mutually advantageous to both BP and Schlumberger. As such, this technology development was advanced as a collaborative effort.
At the outset, the collaboration team identified the technology as being suitable for the intended application. Together, team members focused on the rapid development, construction, and field-testing of the rotary steerable system. Over a 9-month period, the system was designed, tested, and deployed by teams working concurrently in the UK and the USA. Prior experience gained with smaller hole sizes was used to design the system, including both the bit and the steering unit.
The approach taken by BP asset teams in the Gulf of Mexico and Schlumberger contributed to accelerated initial field testing of the system in January 2002. Initial field trials proved successful. In its first application, the system was used to kick off from vertical, achieving a build rate of more than 3°/100 ft. Subsequently, the system has proven beneficial in other projects, and the value of the collaboration has been clearly demonstrated.
Continuous Direction and Inclination Measurements Lead to an Improvement in Wellbore Positioning
Authors: Stockhausen E. J. , Lesso W. G. 
Published: December 2007

Abstract
The measurement of continuous real-time inclination provides near instantaneous calculations of the build-up rate tendency of a bottom hole assembly in both rotary and slide drilling modes. The addition of an azimuthal measurement now allows for the calculation of wellbore position with this continuous data. The true nature of the wellbore curvature in slide/rotate directional drilling with steerable systems is lost when using the typical 90-foot survey interval. Continuous surveying shows this effect. When wellbore position is calculated with the continuous surveys, a significant positional discrepancy from the stationary surveys can occur.
A study was conducted using both stationary and continuous survey data from over 20 wells in Nigeria, Angola, the Gulf of Mexico, the North Sea and Indonesia. The objective was to determine the magnitude and scope of TVD positional error caused by the different slide and rotate curvatures between stationary surveys on a wide range of wells. These curvatures are not reamed out as commonly thought. They can still be seen in continuous gyro surveys taken after drilling has finished. This positional effect is not a function of the sensor accuracy, but it is a result of the environment in which surveys are measured. We show that in a horizontal well the effect can accumulate up to plus/minus 25 ft TVD. The implications of these results are far reaching. Survey positions are used in creating structure and reservoir maps, which are used in determining reserves and recovery efficiencies, and in turn for making field management decisions.
This paper highlights the results of the field studies. A review of rotary steerable system operations shows that the effect is much less than with steerable motors, but can still be of concern.
A low-cost solution for effectively determining when to slide and rotate with respect to the stationary survey is presented. This procedure results in a positional accuracy that can be maintained without changing survey data management practices.
New Drilling Technology Reduces Torque and Drag by Drilling a Smooth and Straight Wellbore
Authors: Stuart D. , Hamer C. D. , Henderson C. , Gaynor T. , Chen D. C-K 
Published: December 2007

Abstract
Torque and drag can be critical issues in drilling directional wells especially in extended reach drilling (ERD). During well planning, torque and drag must be projected to ensure the rig's rotating and hoisting equipment are adequately sized and to evaluate the limits for slide-oriented drilling motors. Depending upon formations, typical open hole friction factors (FF) used in simulation range from 0.22 in oil base mud to 0.35 in water based mud. These friction factors are scaled to a higher value than those measured in the field in order to account for tortuosity created by drilling assemblies.
A new drilling technology has been developed with the objective to reduce torque and drag by drilling a smooth and straight wellbore. The technology involves extended-gauge bit design with a matched steerable motor system or a point-the-bit rotary steerable system. Friction factor was studied for North Sea's wells drilled by the conventional motor systems and by new drilling systems. Significant reductions in the actual friction factors and the tortuosity index have been seen from the wells drilled by the new drilling systems.
Rotary Steerable Drilling System for the 6-in Hole
Authors: Downton G C , Carrington D 
Published: December 2007

Abstract
The availability of a reliable 3D rotary steerable system in 6-in. hole size opens up considerable opportunities to develop reserves where 3D steering is required, but the risks, difficulties, and delays involve in using bent housing mud motors are excessive.
On 10 April 2002, parallel field trials of a 3D, 6-in. rotary steerable system (RSS) started in Oman and the North Sea. The field trials program finished in June with more than 16,000 ft drilled and more than 400 circulating hours experience accumulated in a range of formations without failure. During these trials, the tool displayed steerability and dogleg performance suited to landing and geosteering a well in the reservoir section.
The paper outlines the principles of operation and performance capabilities of the system including the technical challenges encountered while developing a rotary steering system of this size. Field trial results from the test program are presented for a range of drilling conditions, formations, bit types, and bottom-hole assembly designs.
HP/HT Rheology of Aqueous Compressible Fluids for Underbalanced Drilling Using A Recirculating Rheometer
Authors: Kakadjian Sarkis , Herzhaft Benjamin , Neau Laurent 
Published: December 2007

Abstract
When drilling underbalanced, the pressure of the drilling fluid is maintained at a value below the formation pressure. In order to lower well pressure, specific low density fluids are needed i.e. gas, aerated mud or foam. Foam is particularly beneficial for drilling mainly due to its low density coupled with good carrying capability, but its use remains hazardous due to the incomplete knowledge of its bottom-hole properties and especially of its flowing properties. Predicting the pressure drop while drilling with a compressible fluid is not an easy task and for this purpose, knowledge of its rheological properties is of primary importance.
This study is part of a research program conducted in order to improve the knowledge on aqueous aerated fluid and foam properties for drilling. A specific HP/HT rheometer has been built which is able to measure rheological properties of compressible fluids under pressure (up to 50 bars) and temperature (up to 90 °C) conditions. The compressible fluid is circulated through calibrated tubing and the resultant pressure drop is measured as a function of the experimental conditions. A re-circulating set up allows to circulate the foam at a specific shear rate condition until the structure (and the resultant shear stress) is equilibrated. This is of particular importance because the structure of an aerated fluid subjected to a shear rate evolves to an equilibrated value characteristic of a steady state, doing measurement on an structure evolving fluid is indeed non valid. A visualization cell coupled to an image acquisition device permits to characterize the structure of the foam in parallel to the rheological measurement.
Experiments were performed with a specific foaming system already used on site for drilling application. Rheological evaluations at several pressures, temperatures and fluid qualities were investigated. Existing model were tested and showed their limits. Interpretations of the data incorporating the importance of foam structure are proposed to help building a coherent model. These measurements allow a better understanding of the compressible fluid properties under pressure and temperature conditions and will be extended in a near future with reservoir fluid contamination experiments.
Asphaltene Deposition Prediction and Control in a Venezuelan North Monagas Oil Field
Authors: del Carmen García María , Henríquez Magaly , Orta José 
Published: December 2007

Abstract
Asphaltene deposit formation is a severe problem frequently faced during crude oil production and transportation, that affects the reservoir, production tubing and surface facilities, depending on the stage where this critical point is reached. This point corresponds to the pressure at which asphaltene particles start to form. This value is directly related to the oil physical chemical stability. When flocculation pressure is reached into the reservoir, severe formation damages occur due to asphaltene precipitation in the porous media, evidenced as wettability and/or relative permeability alterations. When asphaltenes precipitate in the production tubing, refractory plugs reduce or even stop crude oil production until chemical/mechanical removal is performed. The stability of several crude oils produced in a North Monagas oil field (Carito) from Venezuela, in terms of asphaltene deposition, was evaluated to predict their behavior and prevent future plugging. "Spot Test" and n-heptane titration (asphaltene flocculation onset determination under atmospheric conditions) were used as crude oil stability criteria. Solid deposits, from these wells production tubing and surface facilities, were characterized in order to establish if their origin was organic (asphaltenes or paraffins) or inorganic (scales or sand), and to confirm the stability results assessed in the first set of experiments. Once the asphaltene problem was identified, several commercial asphaltene inhibitors were evaluated, considering their efficiency when a fixed dosage of these products was added to the studied crude oils. Dead oil n-heptane titration of treated crude oils allowed identifying the products that induced higher flocculation onsets when compared with untreated sample results. A second condition that was evaluated for inhibitor selection, was the product thermal stability, considering that downhole treatments would require to face temperatures as high as 150°C. Results of some practical applications derived from this evaluation are presented in this work.
Steamflood Surveillance in Sumatra, Indonesia and San Joaquin Valley, California Using Steam Identification, Carbon/Oxygen, and Temperature Logs
Authors: Zalan Thomas A. , Badruzzaman Ahmed , Julander Dale , Whittlesey Karen 
Published: December 2007

Abstract
ChevronTexaco has developed leading edge data acquisition and interpretation strategies to monitor steamfloods in Sumatra, Indonesia and San Joaquin Valley, California. This paper reviews ChevronTexaco's current steamflood surveillance techniques, and how learnings from San Joaquin Valley are adapted to operations in Sumatra.
Risked Reserve Estimates for Complex Prospects
Authors: Skates Jeff 
Published: December 2007

Abstract
To find oil, drill near an oil field - the cheapest and lowest risk reserves are commonly found as extensions of existing fields, or updip from "near-miss" exploration wells, or simply in prospective acreage which has had many prior discoveries. In these cases, there is more well control and some risks have already been eliminated or minimised compared to the traditional wildcat. The most attractive prospects may also have stacked pay or other multiple targets. In either case, to best estimate the risks and rewards involved in developing these resources, attention to detail is required. Proper accounting for dependencies among different risk factors is required, in order to evaluate the overall risk, the risked reserves distribution, and thus the economic value. The techniques can be extended to value a prospect portfolio, accounting for common or related risk elements.
Reliable and Cost Effective Reservoir Characterization of Thin, Layered and Heterogeneous Reservoirs: Case Studies
Authors: Singh C. S. , Singh J. , Baruah N. , Neog P. K. , Talukdar B. N. 
Published: December 2007

Abstract
In this era of cutting-edge technology where stochastic and geostatistical modelling is the order of the day, conventional layer-cake modelling for highly heterogeneous reservoirs in two fields have yielded very good results. The performance predictions of reservoir simulation studies based on the conventional geological model of these fields are in close conformance with the actual production behaviour thus substantiating the efficacy of such type of modelling.
The results of these studies recommended that additional wells be drilled for augmenting production and recovery. Mapping of advancing edge-water front from simulation based on the 3D seismic derived geological model helped in optimal positioning of the development well locations. Although the role and accuracy of geostatistical and stochastic modelling can not be denied, conventional layer-cake modelling, within certain limitations, is a fairly reliable and cost-effective reservoir characterization tool.