bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hole Cleaning in Large, High-Angle Wellbores
Authors: Rasi Marco 
Published: December 2007

ABSTRACT
Beds of cuttings are usually formed on the bottom of large, high-angle wellbores during drilling. When the drill string is moved axially along the wellbore, large bottom-hole assembly elements such as drill bit and stabilizers tend to plow the cuttings bed, thereby causing the formation of plugs of cuttings which give rise to high overpulls, loss of circulation, continuous need for operations such as backreaming, and stuck pipe. To reduce the likelihood of these costly hole problems occurring, it is necessary to minimize the height of the cuttings bed which forms while drilling, and to minimize the tendency of the bottom-hole assembly to form plugs of cuttings. This can be done with a new hole cleaning tool described in this paper. This tool was developed using a combination of analytical modeling based on fluid mechanics first principles, experimental data, and field data. The tool enables establishment of pump flow rates, drilling fluid rheological properties, drill string configurations, and well profiles for minimal risk of experiencing problems associated with the existence of a cuttings bed.
New Nozzle To Increase Drilling Rate by Pulsating Jet Flow
Authors: Liao Rongqing , Wu Jiang , Juvkam-Wold H. C. 
Published: December 2007

ABSTRACT
A new type of jet nozzle for drill bits used in the oil industry is presented in this paper. This new nozzle utilizes Helmholz oscillation theory and generates a pulsating jet flow under common drilling hydraulics conditions and pump horsepower. This pulsating jet flow produces much higher instantaneous jet velocity and impact pressure than those from currently used jet nozzles, resulting in significant improvements in hole cleaning and drilling rate.
The new nozzle can be used in conventional jet bits without modification. No auxiliary equipment is needed downhole or at the surface to generate the pulsating jet flow. Field tests of this new nozzle in six oil fields in P.R. China have shown that the nozzle can increase drilling rate 36 - 77 %, and increase bit footage 6-44 %.
The theory and the laboratory test results with the new nozzle are presented in this paper. The field test results with the new nozzle are also presented and compared with the results from conventional nozzles. The field test results indicate a satisfactory economical benefit for this new nozzle in drilling both shallow wells and deep wells up to 15,000 ft.
An Expert System for Drill Bit Selection
Authors: Fear M. J. , Meany N. C. , Evans J. M. 
Published: December 2007

ABSTRACT
An expert system has been developed to assist with the selection of poly-crystalline diamond compact (PDC) drill bits. The system uses a knowledge base of bit selection rules to produce a generic description of the most suitable bit for a particular set of drilling and geologic conditions. The rules are derived from rigorous study of foot-based drilling, geology and rock property data from past bit runs. Compared to conventional bit selection methods this approach makes more effective use of past experience, leading to a higher and more uniform level of bit selection expertise in drilling operations.
The Successful Use of Anti-Whirl Technology in Conventional Coring
Authors: Armagost W. K. , Sinor L. A. 
Published: December 2007

ABSTRACT
Anti-Whirl PDC bit technology, proven in full-hole bit designs, has been successfully applied to conventional coring operations. Coring operations were conducted during Amoco's Deep Water Drilling Program in water depths ranging from 3250 to 6521 ft. This paper reviews the coring operations on three wells and compares the results to those achieved in other Deep Water applications. Also included are the results of laboratory testing to establish hydraulic levels required to core Gulf Coast shales.
Lean Drilling – Introducing the Application of Automotive Lean Manufacturing Techniques to Well Construction
Authors: de Wardt John P. 
Published: December 2007

ABSTRACT
In the automotive industry, Henry Ford and Alfred Sloan moved manufacturing from craft production (highly skilled workers using simple but flexible tools to make what the customer asked for – one at a time) to mass production (narrowly skilled professionals who design products made by unskilled or semi skilled workers tending expensive, single purpose machines). Later Eiji Toyoda and Taiichi Ohno pioneered the concept of lean production which combines the advantages of craft production and mass production whilst avoiding the high cost of the former and the rigidity of the latter.
The application of lean production created the most developed form of customer – supplier relationships (being developed elsewhere under the guise of alliances and partnerships) and achieved the highest productivity and quality in the industry. Studies have shown that productivity exceeds mass production by as much as fifty percent and the associated high level of quality is free. This outstanding result was not achieved through automation but through development and adoption of new organizational concepts. The drilling industry today resembles most closely the automotive craft production of the past; mass production has not been adopted due mainly to the non repetitive nature of drilling activities. Studies have concluded that lean manufacturing can replace both mass production and craft production in all areas of industrial activity. Lean manufacturing consequently has the potential to be applied to drilling or, more appropriately, well construction.
This paper describes the key elements of lean manufacturing and presents an analogy with the well construction industry which provides the necessary insight for the well construction industry to adopt them. The results achieved in the automotive industry show that major cost savings and improvements in quality can be achieved in the well construction industry through this application.
A New Generation of Instrumented Steerable Motors Improves Geosteering in North Sea Horizontal Wells
Authors: Peach S. R. , Kloss P. J. C. 
Published: December 2007

Abstract
Formation evaluation measurements in conventional steerable assemblies are lagging 30 ft – 100 ft behind the bit. This paper describes a fully instrumented steerable downhole motor recently introduced and proven in several North Sea horizontal wells.
The tool makes real time measurements of inclination, gamma ray and resistivity acquired at, or close to, the bit. These measurements, integrated into the steerable motor, have enabled complex horizontal wells to be drilled successfully.
Provision of inclination at the bit measurements enabled the wellsite engineers to continually determine the directional behavior of the bottom hole assembly. The reservoir entry point was determined immediately the bit penetrated the formation, gamma ray and resistivity measurements were used to correlate the position of the bit relative to offset wells. The use of the new instrumented motor enabled a specific horizon within the reservoir to be accurately followed.
The paper discusses operational aspects of the new instrumented motor. A case history is presented along with data from other field trials which include comparisons between data acquired by the instrumented motor and that acquired by conventional Logging While Drilling (LWD) tools run in the same hole section.
Simple Charts to Determine Hole Cleaning Requirements in Deviated Wells
Authors: Luo Yuejin , Bern P. A. , Chambers B. D. , Kellingray D. S. 
Published: December 2007

ABSTRACT
Optimization of hole cleaning remains one of the major challenges when planning and drilling high angle and extended reach wells. In this paper, a simple rig-site graphical technique is presented for determining hole cleaning requirements for a range of hole sizes. The method uses a set of charts which have been derived from a computer model based on both laboratory and field measurements.
Access to the technology at the rig-site has been greatly improved by the development of the simplified charts. Examples are presented which illustrate how the charts can be applied to determine the influence of the major drilling variables on hole cleaning requirements. Mud rheology is shown to be a key variable for optimising hole cleaning in deviated wells. The charts can also be used to quantify the effect of hole enlargement which adversely affects hole cleaning.
In addition, the paper discusses the detailed methodology behind the development of the charts from the original physically-based model. The charts presented in the paper are valid for the typical North Sea drilling conditions.
Pore Pressures, Fracture Gradients, and Drilling Economics
Authors: Proehl T. S. 
Published: December 2007

Abstract
Introduction
Risk sharing and alliance formation are central themes in the E&P business environment of the 1990s. A common manifestation of these themes is the recruitment and use of partners and contractors to perform drilling operations on specific projects which formerly would have been 100% managed and operated by large integrated oil companies. One consequence of risk-sharing activity is that integrated companies have had the opportunity to closely observe and assess the drilling practices of other operators and incentive-oriented drilling contractors on wells in real time, with funds at risk.
The debate over which kind of business organization and risk-sharing philosophy produces the most cost-effective drilling result often neglects the fact that for any given well, the in-situ conditions would be identical for anyone undertaking the work. There is no inherent logic in the notion that turnkey contractors have an edge on oil companies in addressing subsurface conditions. The economic outcome of a given well is more dependent on objective subsurface factors and the way they are approached than on the kind of risk-sharing philosophy selected for drilling. Similarly, there is no inherent logic in the notion that hiring a turnkey contractor absolves an oil company from risk on a well. At a minimum, the risk of possible production delays caused by acts of a turnkey contractor is always present.
Three wells (A, B, and C) drilled recently illustrate the point. One well was drilled by an oil company and two were drilled by turnkey contractors. All three wells penetrated geopressured sections. The resulting geopressure-related problems with fracture gradients and wellbore integrity caused large economic impacts on turnkey drillers and operators alike. The wells were selected to highlight the common-sense idea that the key to risk management and achieving profit goals is good planning and proper execution, not the form of risk-sharing selected for any particular venture.
Recent Advances in Subsea Completion/Workover Blowout Preventers
Authors: Womble L. M. 
Published: December 2007

ABSTRACT
Several recent advances have been made in subsea completion/ workover blowout preventers (BOPs) which reduce the cost, weight, size, and time required for subsea workover and completion applications while maintaining safety. Newly released ram designs have made broad steps in the areas of shearing, suspending, and sealing. In addition to new rams, new approaches to bonnet design have increased the features while decreasing the size of subsea workover BOPs. The primary focus of these designs is the increased use of coiled tubing for drilling, completion, and workover operations. In most cases these new advances will cut the required number of ram cavities for a dual string system in half and eliminate at least one trip down hole. These designs have been proposed for use in subsea tree running tools, lower riser packages, subsea BOP blocks, cutting packages, and traditional workover BOP stacks.
Data Gathering for a Comprehensive Hydraulic Fracturing Diagnostic Project: A Case Study
Authors: Truby L. S. , Keck R. G. , Withers R. J. 
Published: December 2007

Abstract
ARCO is currently engaged in a comprehensive field project to demonstrate the use of hydraulic fracturing for solid waste disposal. Implementation of this research program includes drilling of three 5000' test wells: an injection well and two offsetting monitor wells that each contain twenty-five 3-component geophone pods for passive seismic fracture detection. This paper focuses on the data gathering during drilling operations and the unique drilling challenges required for this disposal demonstration project. Specialized data was required for assessment of fracture geometry and containment, measurement of fracture azimuth to site the monitor wells and verification of formation seismicity for fracture diagnostics. This information was obtained with extensive coring operations, open- and cased-hole micro-fracs, and an injection test to directly measure the formation seismicity. Drilling challenges included the placement and cementing of the 750' of geophone pods and 4250' of armored transmission cable in each monitor well, plus redesign of well plans due to wellbore stability problems.
Ravenspurn North Development Drilling: Key Techniques to Outstanding Success
Authors: Bird T. M. , Sears R. W. , Ollis Michael , Dickson Robert , Ferguson R. A. 
Published: December 2007

ABSTRACT
This paper presents an overview of how the drilling performance on Ravenspurn North Development (RND) constantly improved resulting in significant savings in well costs. Performance statistics showing the learning curve effect and comparison of RND drilling performance with other Southern North Sea developments(1) are presented. Several key techniques contribute to this success including optimisation of well design, use of leading edge technology and performance monitoring. These topics are discussed along with specific examples of how they were applied.
Analysis of Interruption and Lost Rig Time Due to Equipment Failure in Offshore Drilling Operations
Authors: Andersen L. B. , Lembourn P. R. 
Published: December 2007

ABSTRACT
Database records and maintenance reports were used to analyse lost rigtime during drilling operations on the Norwegian Continental Shelf (NCS). The equipment failure database contains detailed and unique information from more than 13,700 incidents of equipment failures that caused lost rigtime from 1985 to 1991. In addition to maintenance reports, the database records were used to survey to what degree equipment failure causes lost rigtime, what kind of equipment fails most often, and in which operation the equipment failure occurs. Emphasis was put on analysing the causes for "Top Drive" failure. The results presented in this paper represent an average in lost rigtime on the NCS and can therefore be used as a measure in the Continuos Improvement Process. The analysis of "Top Drive" failure is an example of how a causal analyses can be conducted, and of how the results can be utilised in improvement efforts.
Smooth Block Control: Automation of Traveling Block Postioning Using Existing Drilling Equipment
Authors: Zinkgraf H. L. , Porche M. N. , O'Brien D. M. 
Published: December 2007

ABSTRACT
Automation of drilling rig functions can improve efficiency by reducing personnel and operating costs while providing an additional benefit of increased safety. Methods which use existing drilling equipment provide the most economic means to implement this automation. One function which can be implemented in this way is automatic positioning of the traveling block.
This paper examines general design requirements for achieving automatic positioning of the traveling block. It also presents details of a control system developed to provide controlled braking of the traveling block using previously installed eddy current brake systems. The system provides closed-loop braking control while monitoring the traveling block position, velocity and acceleration through its entire range of travel. Various parameters are constantly monitored to assure that the eddy current brake capacity limits are not exceeded at any time. The system smoothly stops the traveling block at positions selected by the operator, even with wide variations in load. Sensors may be added to prevent moving the traveling block to collide with pipe handling equipment. The advantages of closed-loop control utilizing eddy current brakes over kinetic energy monitoring and friction brake application will be detailed. The technical requirements for future extension of this system into a full automatic positioning controller are discussed.
Field performance data will be presented to illustrate the benefits obtained from closed-loop control of the eddy current brake to position the traveling block.
Tracking Stuck Pipe Probability While Drilling
Authors: Howard J. A. , Glover S. B. 
Published: December 2007

ABSTRACT
Two stuck pipe databases have been developed with data from more than 1000 wells drilled in the Gulf of Mexico and the North Sea. Statistical techniques were used to develop stuck pipe predictive models. When classifying in three categories - differentially, mechanically or not stuck - an accuracy of 75 % is achieved, rising to 80% for two-class (stuck/not stuck) prediction. Using these models, graphical tracking of the probability of stuck pipe occurring may be undertaken, to monitor drilling operations for stuck pipe avoidance. A similar statistical model was developed to predict the probability of freeing pipe once stuck. Comparisons are also made with two published pipe-freeing models. The data were further analysed to identify any trends which may provide operational guidelines for stuck pipe avoidance or freeing operations.
Advances in Prediction of Stuck Pipe Using Multivariate Statistical Analysis
Authors: Biegler M. W. , Kuhn G. R. 
Published: December 2007

ABSTRACT
Stuck pipe is known to occur as a result of several major mechanisms including wellbore instability, improper hole cleaning, and differential sticking forces. Using an evolution of the discriminant analysis methodology first published by Chevron1,2, a second generation engineering statistical model has been developed that incorporates the use of physical stuck pipe parameters in combination with a large body of drilling data to quantify the probability of stuck drill pipe for a given day of a well. Further, the tool predicts which stuck pipe mechanism is driving sticking risk and can thus be used to modify drilling variables to minimize the likelihood of sticking. An example application of the model in a recent Gulf of Mexico well is given.
Recent Advances in Casing Wear Technology
Authors: Hall R. W. , Garkasi Ali , Deskins Greg , Vozniak John 
Published: December 2007

ABSTRACT
Casing wear is often a problem in deep wells where doglegs and large tension loads on the drill string combine to produce high lateral loads where the drill string contacts the casing. Casing wear can result in blowouts, lost production, and other hazardous and expensive problems.
A mathematical model which describes casing wear in terms of hole geometry, casing/tool-joint material, mud system, and drilling program, has been developed and verified. Over 300 laboratory wear tests have provided wear factors which allow the model to be applied to a wide range of drilling situations. The model has been incorporated into a computer program, CWEAR.
The prediction of dogleg severity and casing wear is seriously compromised by directional surveys in which the station spacing is 100 ft or greater.
Through the laboratory test program, means to reduce casing wear rate have been demonstrated and applied in the field.
Mud lubricants, tool-joint materials, pipe protectors, and casing materials and internal coatings have all been examined as possible means to reduce casing wear.
Some mud lubricants significantly reduce frictional drag; others do not. Because a mud lubricant significantly reduces frictional drag does not imply that it will also reduce the casing wear rate.
Newer, proprietary tool-joint coating materials have proven effective in reducing casing wear, while continuing to protect the tool joints in open hole.
Pipe protectors have proven to be one of the better means of reducing casing wear. Laboratory experiments have demonstrated severe operational difficulties of these protectors. Several of the protector manufacturers are now engaged in development programs to improve their products.
Inadequacies in the available methods of measuring casing wear in the field have been demonstrated. As a result of this work, at least two new casing wear measurement tools are under development.
Geothermal Gradient Anomalies of Hydrocarbon Entrapment, UKCS Quadrants 35 to 54
Authors: Ibrahim M. W. I. 
Published: December 2007

ABSTRACT
Geothermal Gradient anomalies have long since been recognised to accompany hydrocarbon traps. The anomalies are most probably byproducts of heat transporting processes of hydrocarbon migration and entrapment. Therefore, couldn't identical anomalies be used to locate undiscovered or bypassed traps?
This study used BHT data of exploration and development wells in UKCS guadrants 35 to 54 of the North Sea to: produce contour maps of the geothermal gradients, identify geothermal gradient anomalies associated with proven hydrocarbon traps then use the models identified to delineate potentia, probable and possible anomalies indicative of undiscovered hydrocarbon traps or migration paths in the same quadrants.
A computer programme (CGG-ESTI) was used to correct and test for reliability the BHT records of 238 wells in order to identify boreholes with statistically significant BHT data. Discriminative computer contouring technique was used to produce noninteractive, un-biased contours similar to the manual after-the-fact contours. This technique utilised statistically significant as well as undifferentiated control points to generate compensated geothermal gradient contours (CGG), extrapolated surface temperature intercept contours (ESTI) and map geothermal gradient anomalies of hydrocarbon entrapment.
The study delineated 50 PROVEN and 46 POTENTIAL, PROBABLE and POSSIBLE geothermal gradient (CGG-ESTI) anomalies of hydrocarbon entrapment.
The Geopseudo Atlas: Geologically Based Upscaling of Multiphase Flow
Authors: Pickup G. E. , Ringrose P. S. , Forrester M. M. , Jensen J. L. , Sorbie K. S. 
Published: December 2007

ABSTRACT
Recent work has shown that rock heterogeneity at the sub-metre scale may have a significant effect on hydrocarbon recovery. These effects need to be upscaled to obtain accurate effective parameters (pseudo properties) to input into full field simulations. Modelling the wide range of scales inherent in hydrocarbon reservoirs is a demanding task which can be greatly assisted by a purpose-built software package. We are therefore developing the Geopseudo Atlas package to address this need. The package integrates reservoir simulation with recent advances in geological modelling, allowing the engineer to create permeability models which are geologically realistic, and to calculate the effective flow properties of such models. It is designed to complement the many existing large-scale reservoir modelling packages. The Geopseudo Atlas is intended to be an important tool linking geological models, data, and reservoir simulators.
The package comprises four sections: the Atlas which contains a selection of ready-worked examples; Data Analysis which performs simple statistical analysis on available data; Field Generation which creates deterministic and stochastic permeability models; and Scale-up which performs single and two phase flow simulation. The Geopseudo Atlas is menu driven and runs on Unix-based machines with Motif. It is intended to interface with commercially available packages, such as the ECLIPSE™ reservoir simulation package, and STRATAMODEL™ and IREX™ for 3D visualisation.