bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the Working Environment and Drilling Economics through Better Understanding of Oil Based Drilling Fluid Chemistry
Authors: James R. , Navestad P. , Schei T. , Geddes T. , Nelson G. , Webster D. 
Published: December 2007

Abstract
The relationships between oil based drilling fluid composition and the associated vapours have been quantified. This information will provide drilling Operators with improved control in the working environments. The study documents the long and short term changes in base oil selection and fluid compositions. The study is based on the generation and assessment of data collected from the vapour emissions of oil based drilling fluids with varying compositions and at a range of temperatures.
Mineral oil based drilling fluid samples from the field have been investigated and compared to laboratory samples of similar basic composition. The impacts of other components in the drilling fluid formulations are also discussed.
The purpose of the study was to enable a better understanding of the potential working environment hazards when using mineral oil based drilling fluids. One result of this understanding is that new rig construction designs, and older rig upgrades can be more informatively performed. Consequently this will reduce the repetition of continual modification costs.
Cost Savings through an Integrated Approach to Drillstring Vibration Control
Authors: Kriesels P. C. , Keultjes W. J. G. , Dumont P. , Huneidi Issam , Owoeye O. O. , Hartmann R. A. 
Published: December 2007

Abstract
Drillstring vibrations occur frequently during drilling operations. They can result in drillstring failure, fishing and, in the worst case, side tracking. At the same time, the rate of penetration and the bit/downhole tool longevity are reduced. All these effects of drillstring vibrations lead to substantial additional well cost.
An integrated approach towards vibration control, addressing all the contributing factors, can have a positive impact on well costs. This is especially true for hard rock drilling, as frequently occurring in Middle East countries. Various types of vibration can be distinguished, each having their own specific adverse effects. The integrated approach, developed in Shell, consists of the following elements:
The application of a soft torque rotary system (electric and hydraulic rotary drives) for suppressing (torsional) stick slip vibration of BHA and bit. The use of vibration analysis software in the design of a BHA, to prevent buckling and to identify safe operating windows for rotary speed. The cost-effective deployment of vibration monitoring tools. The regular inspection of drillstring components.
Field cases of the deployment of this methodology reveal that twist-offs can be reduced by more than 80% and drilling performance in terms of ROP and bit life can be improved. Cost savings are realised through the reduction of well days and prevention of tool failures. A limitation of the method is that safe operating parameters are not available under all circumstances.
Theoretical Maximum Performance, ProStar Rig 2000
Authors: van der Leij E. , Zuidema F. , van Tuyl G. , de Jong P. , Anderson B. 
Published: December 2007

Abstract
The PT 2000 was built as a state-of-the-art land drilling rig designed to achieve safe and efficient operations through automation and the removal of personnel from the working envelope. After two years of mediocre performance, Theoretical Maximum Performance (TMP) was adopted as a method for improving rig operations by developing people in the workplace. Performance coaches were placed on the rig for a twelve-month period. They encouraged innovative thinking and greater commitment to the job. By invoking numerous tools around the Plan / Execute / Measure / Learn continuous improvement cycle, the crew of the PT 2000 achieved sub-stantial performance gains, specifically in rig move times, rig downtime, and BOP Testing. The rig's impressive safety record was not compromised. Using this approach, the PT 2000 drilled five wells in 1998 and saved 71 days from the budgeted time for these wells. Deutag Drilling sees this innovative approach as a valuable contribution to its business.
Successes in Production-Liner Cementing in Oil-Based Mud: A Case Study
Authors: Al Khayyat Bader , Morris Jesse A. , Salahudin Sharifudin , Ravi Kris , Faria Juvenal 
Published: December 2007

Abstract
The 8½-in. hole sections of two fields in Kuwait have historically presented drilling problems associated with swelling shales and differential sticking. This drilling problem was alleviated by changing from a water-based drilling mud (WBM) to an oil-based mud (OBM). The change from WBM to OBM significantly reduced drilling problems; however, zonal isolation in the sand and limestone sections suffered, causing poor cement-bond logs across the 7-in. production liners. This paper presents the case histories of several wells in which zonal isolation problems were overcome, and production liners were successfully cemented.
In an attempt to determine the nature of the cementing problems in these two fields, the authors thoroughly analyzed the wells and completion designs. They reviewed formation properties, hole condition, mud properties, slurry and spacer designs, openhole logs and cement bond logs (CBLs), and the placement techniques of the affected wells. This paper documents the conclusions of this study, as well as the products and processes that significantly improved the zonal isolation of the 8½-× 7-in. annulus. CBLs performed across the intervals of four wells drilled with OBMs and cemented with improved products and processes indicate significantly better bonding than previous logs. These wells are currently on production and are being observed for short-and long-term performance.
A New Well Design and Construction Process
Authors: Clay Tim , Hatch Andy 
Published: December 2007

Abstract
The upstream oil and gas industry is being increasingly challenged by market price volatility, higher exploitation costs and growing environmental concerns. Working in the mature UK North Sea province, ARCO British Limited has recognised that it needed a better business process to deliver consistent, top-performing well execution in both exploration and development projects. A multidisciplinary process redesign team identified that approximately 70% of the deficiencies in the previous ABL process lay in lack of project definition and planning rather than in poor execution.
A new process has been rolled out which uses both front-end loading techniques to identify the best economic execution plan and organisational learning to achieve repeatable high performance. Recent project successes indicate that a fit-for-purpose well design and construction process has been established.
Trial of an Expandable Sand Screen to Replace Internal Gravel Packing
Authors: van Buren Mark , van den Broek Léon , Whitelaw Calum 
Published: December 2007

Abstract
In January 1999, Petroleum Development Oman installed an Expandable Sand Screen in the Rahab field. The expandable sand screen was installed across a newly perforated production interval in an existing well. The low production potential precluded the economical installation of an Internal Gravel Pack across the new interval for mandatory sand exclusion. On the other hand, the limited production exposure provided an opportunity to trial a novel, potentially more economical, alternative to gravel packing. The opportunity was therefore taken to trial an expandable sand screen. This trial is the first application of an expandable sand screen in a producing well. The installation of the expandable sand screen proceeded smoothly. The sand exclusion performance to date has been exemplary. Production tests show an increase in gross and net production rate in line with expectations.
Successful Drilling of an Underbalanced, Dual-Lateral Horizontal Well in the Sajaa Field, Sharjah, UAE
Authors: Mathes R. A. , Jack L. J. 
Published: December 2007

Abstract
Amoco Sharjah Oil Company (ASOC) has drilled several dual-lateral horizontal wells in its Sajaa Field since 1996. Two of the wells did not reach their geologic and leg length objectives due to massive, incurable lost circulation and several of the wells were hampered by differential sticking. A recently completed well was drilled using underbalanced techniques in order to mitigate or eliminate these occurrences. Dry sales gas from the Sajaa Gas Plant re-injection system was used to achieve the underbalanced condition. A 7" tieback casing string with perforations in the bottom joint was installed prior to drilling the horizontal legs and the gas was injected down the 7" × 9 5/8" annulus. Conventional mud motors and MWD tools were used in the bottom hole assemblies with the addition of a back pressure valve and a " restrictor" sub. Clean water with periodic high viscosity pills was pumped down the drill string. Surface equipment included a rotating blow out preventer (RBOP), a choke manifold with two bladder type adjustable chokes, sample catchers and a four-phase separator. The project was completed ahead of schedule, under budget, and without an accident or serious incident. The two main benefits were achieved plus some additional ones such as increased penetration rates and more efficient sidetracking. This paper discusses the pre-planning and team building conducted prior to beginning underbalanced operations, the surface and down hole equipment involved, the general procedures followed, plus the operating parameters and results experienced.
How To Manage Drill-In Fluid Composition To Minimize Fluid Losses During Drilling Operations
Authors: Cobianco S. , Bartosek M. , Lezzi A. , Guarneri A. 
Published: December 2007

Abstract
Selection of the best Drill-in Fluid for drilling horizontal wells is based, essentially, on the characteristics of the filter cake formed near wellbore region. Minimizing filtrate loss into the formation by forming a thin filter cake with low porosity and permeability is the key to managing formation damage problems.
In this paper the effects of Drill-In Fluids components and their interactions in the formation of a filter cake, which provides an effective caking process with reduced filtrate loss, have been evaluated. A statistically designed experiments carried out with a dynamic filterpress apparatus were used to identify which variables had the most significant effects on the filtrate loss and cake permeability, so that the optimum fluid composition could be determined. These variables include the formation characteristics (permeability and pressure values) as well as the type and amounts of the fluid components.
Data obtained in this experimental design study were analyzed using the multiple linear regression method (MLR) which allowed us to model the filtrate loss and cake permeability. The analysis pointed out that the most important factor is the type and the amount of polymer concentration, particularly an increased concentration of scleroglucan improved the cake permeability and the filtrate loss. An interaction effect between the amount of scleroglucan and the more crosslinked starch was also identified. Besides the results indicated that the other variables did not have any significant effect within the range of experimentation. This fact can be considered as an advantage, as it allows flexibility for the choice of the other factors when deemed appropriate in order to cost reduction.
An Innovative, Environmental Friendly And Cost Effective Approach For Polymer Based Mud System In Upper Assam Oil Fields Of India
Authors: Dayawant S. 
Published: December 2007

Abstract
Depleted reservoir pressures, problematic BCS section, frequent stuck-up formation damage and environment conditions in Upper Assam today, need Polymer based mud to improve the efficiency and effectiveness of drilling operations, to minimize formation damage and ensure maximum production from depleted reservoirs.
Conventionally polymer based mud is used in 8.5 " section against problematic BCS section and deeper producing horizons BMS, Kopili etc. The mud used in earlier phases is disposed off / thrown to the waste pit. Throwing / disposing of mud is a great problem in Upper Assam because of environmental constraints.
An innovative approach has been developed which is not only environment friendly but cost effective too. Lime flocculated and Low lime mud system were used previously to drill down Girujan clay and against (Tipam, BCS, and BMS) respectively.
Under the new approach. Bentonite content is gradually reduced and substantiated with Guar-Gum and XC-Polymer. Lime (Ca++ ions) have been replaced by K+ ions and KC1 flocculated mud system is run in place of Lime flocculated upto Girujan clay. 3 - 5 % KC1 is introduced during drilling Tipam sands to maintain the porosity and permeability intact. The system is fully converted into KCl-Polymcr system against BCS, BMS, and below having 2 - 3 % Bentonite, 3-5 % KC1, 0.1 - 0.2 % XC polymer, 0.2 - 0.3 % PHPA and 0.5 - 1.0 % PAC. Many wells in Gelekey, lakwa and RDS have been drilled successfully with this approach. Thus the approach will fulfill the objective of using polymer based mud without harming the environment.
Polymer base mud in Upper Assam project of ERBC is used because of the following reasons:
Custom-Blending Foamed Cement for Multiple Challenges
Authors: Kimura Kazufusa , Takase Koji , Griffith James. E , Gibson Ronald A. , Porter Dean S. , Becker Thomas E. 
Published: December 2007

Abstract
In some Middle Eastern wells, the serious problem of shallow casing leaks results from an insufficient cement seal across a corrosive water formation containing hydrogen sulfide (H2S). Factors contributing to this poor seal include multiple weak adjacent zones and thin lenticular washouts, which complicate conventional cementing practices by preventing slurries from sealing off water-bearing formations and protecting the well casings. Historically, multistage cementing has only marginally improved zonal isolation in this region. High-quality foamed slurries [slurries with high volumetric concentrations of nitrogen (N2)] can enable coverage of the weak zone, but these slurries are too permeable to provide long-term casing protection.
A joint study conducted to address casing-leak problems in a Middle Eastern field has yielded custom cement blends that mitigate the combined detrimental effects of (1) water containing H2S, (2) mud or whole-cement losses to lost-circulation zones (zones with very low fracture gradients), and (3) muddisplacement deficiencies primarily caused by multiple washed out sections. Successful slurries that appear (based on laboratory results) to combat these problems are foamed with nitrogen and feature a combination of Portland and pozzolan cements plus hollow pozzolan spheres. This paper discusses large-scale tests and the blends designed for these tests. Researchers conducted these tests in an attempt to prove the effectiveness of certain cement blends and to help optimize those blends. The tests show that foamed, lightweight (8 to 10 lbm/gal) slurries containing hollow pozzolan spheres with pozzolan cement can enhance the sealing of harsh-water zones. This enhancement is achieved by the combined effects of two events: (1) improving displacement of drilling mud and cuttings by optimizing foam quality, and (2) cementing past lost-circulation zones. Details of blends, test setups, and test results are discussed.
New Developments in the Mechanized Running of Tubulars
Authors: Harris David , Peyon Albert 
Published: December 2007

Abstract
With the advent of a new generation of ‘Super’ Drilling Rigs, including fifth generation Semi Submersibles, special needs have arisen for casing, tubing and drill pipe make up and running. This paper will describe the following new equipment developed for these rigs.

Power Frame
To run on rails similar to the Hydraulic Roughneck capable of suspending any Power Tongs to run casing and tubing in the range 3 ½-in. to 20-in. and drill pipe up to 6 5/8-in.

Mechanized Casing and Tubing Tongs
These tongs come complete with Free Floating Hydraulic Backups and remote operation capabilities.

Soft PLC Control Systems
Using software to simulate traditional PLC Systems and Profibus Communication Links for the remote operation of the Power Tongs and Power Tong Frames.
A plan for fully automated sequence has been implemented in the system.

Mechanized Drill Pipe Tongs
For the running of special drill pipe and Drill Pipe Test Risers.

Circulating Heads
Specially designed for remote operation and for use with new design side door elevators.
Special issues will be addressed, such as the running of casing in triples, a procedure not previously used in the industry. Anticollision systems for the equipment will also be discussed.
The systems described are unique in that not only will there be make-up equipment at the well center but also at two ‘Outboard Stations’ with mouseholes. By this means, many functions such as prefabrication of stands of risers, drill pipe and bottom hole assembly stands can be carried out offline without interrupting or delaying drilling operations. These functions will also include the fabrication and racking back of triples of casing. Considerable timesaving is anticipated.
The minimizing of any human intervention in these operations on the rig floor is critical to these new mechanized designs. Improvements in safety and operational efficiency are the key reasons for the development of this equipment. "Process driven design" and "Fit for purpose" are the two governing principles permanently followed in this project.
Evaluating High-Angle Wells with Advanced Production-Logging Technology
Authors: Hupp Douglas , Schnorr DeWayne R. 
Published: December 2007

Abstract
High-angle wells with longer and longer departures are being drilled at an ever-increasing pace on the North Slope of Alaska and around the world. This type well is used to penetrate new oil reservoirs and increase oil recovery in older maturing oil fields. The older maturing oil fields are being waterflooded with gas reinjection to maintain reservoir pressure, which results in wells that produce oil with high water cuts and high gas-oil ratios. These complex downhole production profiles create a difficult production logging environment.
A totally new logging tool is being used to determine the production profile when a high-angle well is producing oil with high water cut and high gas-oil ratios. This compact tool directly measures water holdup and gas holdup distribution around the wellbore, along with velocity data and X-Y caliper all 18 in. above the bottom of the tool. Pressure, temperature, inclination, with gamma ray and casing collar locator, are also included in this compact tool. All measurements can be run with an electric line unit or in memory mode. The memory mode eliminates the need for electric line when logging horizontal wells or wells that have high surface flowing pressures.
Sigma/porosity and carbon-oxygen measurements can be combined with this short production logging tool, when run on electric line, so that the production profile and the reservoir behind the casing can be evaluated on a single trip into the well. The combination of the production profile and formation evaluation is then used to determine how to produce the well and manage the reservoir to maximize oil production and recovery.
Production profiles from four different wells demonstrate the value of these direct measurements and how they were used in planning the remedial work to increase oil production and reduce or eliminate unwanted gas and water production.
Oriented Perforating for Sand Prevention
Authors: Sulbaran A. L. , Carbonell R. S. , López-de-Cárdenas J. E. 
Published: December 2007

Abstract
In weak formations or in competent formations with potential for sanding problems from high in-situ stresses, screens and gravel packs often are not practical or economical. However, in such formations, the perforating program can significantly affect the production of sand. With knowledge of the in-situ stress distribution around the target well, the technique of optimal phased and oriented perforating (OPOP) was applied in the Eocene sands of the field in Lake Maracaibo, Venezuela, to minimize sand production. Results were excellent. In this paper, the OPOP technique is described and general guidelines are given for its use. Field cases are presented that compare results gained using this technique to the performance of other wells in the same field.
An Optimal Foam Quality for Diversion in Matrix-Acidizing Projects
Authors: Alvarez Jose M. , Rivas Hercilio , Navarro Geidy 
Published: December 2007

Abstract
The proper placement of acid is a crucial factor in a matrixacidizing project. Unfortunately, much of the acid flows through the less-damage zones, leaving the damage area untreated. Foams have been used to divert the acid to the damage areas. However, the complexity of foam behavior in a porous media has reduced the efficiency of the diversion. Behenna1 claimed that if foam is generated or injected into the less-permeable layer (damage area), or if insufficient foam is injected into the more-permeable layer, diversion is not obtained. More recently, Alvarez et al.2 concluded based in a proposed model, the fg* model, that foam injection in the low-quality regime (low foam quality, fg) is better for acid diversion. They claimed that in this regime, more foam is injected into the higher-permeability layer before switching from foam to acid.
In this study experimental results confirming the implications of the fg* model are shown. Additionally, the experimental results suggest the existence of an optimum foam quality value for improving the efficiency of an acid-diversion work. Experiments were carried out in a composite core (parallel cores) having a permeability ratio of 15. The cores were packed with sand having different particle diameter to obtain the permeability contrast. An anionic surfactant was used in these experiments. Foam quality was evaluated from 95 percent to less than 40 percent. All the experiments were performed at 600 psi outlet pressure and room temperature. The gas used was nitrogen.
The existence of an optimum foam quality for acid diversion implies that matrix-acidizing projects should be designed carefully. Experimental work, such as the one performed in this study, and the fg* model may help to choose in advance the foam quality condition for a particular matrix-acidizing project obtaining a more cost-effective job.