bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliable and Effective Downhole Cleaning System for Debris and Junk Removal
Authors: Haughton D. B. , Connell P. 
Published: December 2007

Abstract
Wellbore debris is responsible for many of the problems and much of the extra costs associated with producing wells, especially in extreme water depths and highly deviated holes. Even a small piece of debris at the right place at the wrong time can jeopardize well production. For this reason, debris management has become a chief concern for oil and gas producers. Considering rig rates and completion equipment costs, debris removal is moving into the realm of risk management.
A clean wellbore is not only a prerequisite for trouble-free well testing and completion; it also helps ensure optimum production for the life of the well. Debris left in the wellbore can ruin a complex, multi-million dollar completion; it can prevent a completion from reaching total depth. And chances are, it will never reach an optimum production level.
These issues are pushing the industry to create reliable, efficient systems for quickly ridding wellbores of harmful debris and larger pieces of junk. This paper describes a vectored annular cleaning system (VACS) that can be used alone or in conjunction with any of an assortment of improved casing scrapers, brush tools, downhole magnet subs, downhole filter tools and junk catchers to optimize the efficiencies and economics of debris removal and save trips.
This paper will focus on the use of the vectored annular cleaning system to collect and remove debris from areas of the wellbore that traditionally are problematic; i.e., above liner tops, where casing size changes, areas with a loss of annular velocity, and wells with little to no circulation. Case histories from the Gulf of Mexico, North Sea and other areas of the world will demonstrate how this technology has reduced problems of debris removal while saving rig time by eliminating trips.
Block to Block Interaction Effect in Naturally Fractured Reservoirs
Authors: Shariat A. , Behbahaninia A. R. , Beigy M. 
Published: December 2007

Abstract
Initially, gravity drainage mechanism in naturally fractured reservoirs was modeled and validated by solving the available analytical equations (e.g. Firoozabadi and Hauge method in 1990). Block to block interaction effect has been included in this model. Then the effects of different parameters on recovery process were investigated and compared with the production mechanism of different models, such as, dual porosity, dual permeability. This work determined that the most effective parameters on recovery process are block height and matrix permeability. Also in the case of capillary continuity between the blocks, vertical fracture permeability has no effect on recovery process. The main conclusion drawn from this work is that reinfiltration causes a reduction in the production rate; however, it has no effect on ultimate recovery. Also it was concluded that trickled oil from blocks above always prefers to reinfiltrate into the matrix blocks below rather than flowing through the fractures. The following limitations and assumptions apply: 1-D flow.System pressure is constant.Fluid viscosities are constant.Fluids are incompressible.Model is valid only for two phase oil/gas system in the presence of immobile water.
Wellsite Permit to Work System for Onshore Australia
Authors: Gouldie T. 
Published: December 2007

Abstract
The Wellsite Permit to Work System is a universal work planning and scheduling system used by most onshore drilling and well servicing operations onshore Australia to assist in performing work safely.
The Wellsite Permit to Work System is part of an overall safety management system providing a means of improving communication, specifying and implementing appropriate work precautions, setting ongoing conditions under which work should be carried out, monitoring of a worksite for health and safety issues while work is being carried out, and inspection of sites following completed work to ensure it is safe to resume other operations.
Other features of the System include:
Permit types are specifically focused on wellsite, not plant, activities Only one permit form is used for all permit types Seven kinds of permits, including Working at Heights, Pressure Systems, and Explosives/ Radioactive System is applicable to both rig and non-rig work Self contained system, easily able to be transferable to work in yards, workshops and for most non-wellsite work System users need to be trained in only one system, with training certification transferable from wellsite to wellsite, regardless of the rig contractor or operating company
By carrying out the necessary precautionary steps and by following the ongoing work conditions as designated on a permit, wellsite workers greatly improve the co-ordination of wellsite activities and significantly enhance safe operations.
The Wellsite Permit Authority under the System is designated as the senior representative of the primary contractor on the location, such as a rig manager or toolpusher. Operating company personnel have the option to authorise permits on site, or can allow contractors to operate the System without intervention.
The Wellsite Permit to Work System has been in use in this format since 2001. An update to the System has recently been implemented by an industry Steering Committee to incorporate improvements to industry standards and capture learning's from the use of the first version.
This universal Wellsite Permit to Work System, used by the majority of onshore operating companies across all types of wellsite work, run by contractors without the need for operating company intervention and focused on wellsite work is said to be unique in the world.
Improved Window Cutting Efficiency Cuts Casing Exits Costs
Authors: Toulouse J. E. 
Published: December 2007

Abstract
Transferring PDC bit technology to milling equipment has resulted in a new casing exit technology that allows window milling and rathole drilling to be performed in one run to improve operational efficiency and cut drilling costs. The new technology expands the performance envelope for casing exits to significantly extend the number of wells that can be re-entered.
Using whipstocks and casing mills to exit existing wellbores has become commonplace. However, this operation is becoming more critical because extended ratholes are often required to accommodate long rotary steerable assemblies before new formation drilling can commence. Depending on window depth, the extra trip required to drill the rathole can take up to two days of rig time and significantly increase well costs.
To address these issues, a new-style formation mill has been developed that borrows from PDC design. to optimize cutting element efficiency and uses a special PDC compound to effectively cut both metal and formation. The mill is adaptable to many whipstock systems or can be run as standalone technology.
Since its introduction, the mill/bit has helped operators in various geographic regions reach new reserves economically. Performance has been closely monitored in applications ranging from through-tubing exits in 4.500 in. tubing to a 13.625 in. casing exit in deepwater salt and a 7 in. casing exit in 30,000 psi dolomite with chert nodules.
The tool has saved numerous trips on simple, hard-rock sidetracks as well as in deepwater plays using rotary steerable drilling systems.
Case Studies—Offshore Managed Pressure Drilling
Authors: Hannegan D. 
Published: December 2007

Abstract
Managed Pressure Drilling (MPD) technology has evolved on land drilling programs since the mid-sixties. However, it has been only fairly recently that the technology has found an important niche in the minds of offshore drilling decision-makers.
With most of the world's remaining prospects for oil and gas being economically un-drillable with conventional-wisdom casing set points and fluids programs, MPD is now being viewed as a technology which can render a significant increase in economic drill-ability by reducing excessive drilling-related costs typically associated with conventional offshore drilling.
This paper will define for the audience the two Categories (Reactive & Proactive) and the Variations of MPD that are being currently practiced or will be practiced in the near future in marine environments:
CBHP (Constant Bottomhole Pressure) PMCD (Pressurized Mud Cap Drilling) Dual Gradient (several methods) HSE (Returns Flow Control)
Case studies will be presented which speak to MPD applications from both fixed (Jackup, platform) rigs with surface BOP stacks…and from floating rigs (moored semi-submersibles and DP Drillships) with subsea and surface BOP's.
There will be an emphasis upon the "drilling trouble zones" benefits of MPD. Operator company objectives of practicing the variations of MPD will be detailed. Stances of various regulatory agencies will be briefly discussed.
Reservoir Management of West Salym Oil Field
Authors: Svirsky Dmitry , Hagelaars Ad , Zegwaard Joost , Mackay Howard 
Published: December 2007

Abstract
The West Salym oil field in West Siberia is a new development recently brought on stream in this mature petroleum basin. The field contains some two bln stb of oil in place. First oil was produced in 2004 and peak production is expected in 2012 at over 100,000 stb per day. Whilst the field is in an early development stage, it is crucial that reservoir management and data acquisition processes are put in place to allow efficient future field development and optimise oil recovery.
The paper focuses on four main aspects of the West Salym development: project management, well and reservoir surveillance, reservoir management and petroleum resources maturation. In the project management section the multi-disciplinary integrated team approach implemented in the sub-surface asset and field operations teams is highlighted. In combination with technology support from world-class technical expert groups, this allows effective implementation of surveillance and reservoir management activities in the field. In the reservoir surveillance section an overview of the field surveillance program is provided and experience of using surveillance technologies in West Siberia such as hi-end logging, wireline formation testing, specialised core analysis and geochemical fluid analysis is described. The reservoir management section concentrates on several technical aspects of West Salym development, such as well pattern and reservoir stress alignment, application of highly deviated wells as an alternative to hydraulic fracturing and management of water injection under fracturing conditions. The petroleum resources maturation section describes how the reservoir management activities result in the maturation of the field petroleum resources to reserves and improvement of oil recovery. Technology opportunities for innovative wells, permanent downhole metering and enhanced oil recovery processes are also reviewed.
Case Study: Subsea Intervention With a Jack-up Drilling Rig
Authors: Hargreaves B. , Mohr J. W. , Snow T. M. , Mamuko B. O. 
Published: December 2007

Abstract
ExxonMobil1 subsidiary Esso Australia Pty Ltd recently completed the first subsea intervention using a jack-up drill rig in Bass Strait, Australia. This case study provides an overview of the intervention and how the key challenges were overcome.
Prior to the intervention, the Seahorse-1 subsea well was producing 150 BOPD at 95% water cut from two stacked commingled zones. Reservoir analysis indicated that the more permeable lower zone dominated the commingled flow leaving unproduced reserves in the upper zone. The scope of the intervention was to isolate the lower zone so that the upper zone could be produced more effectively.
The nature of the intervention presented several key challenges: (i) there was uncertainty associated with availability and condition of the 16 year-old subsea equipment that had not been used since installation, (ii) potential to modify a jack-up rig was only identified four months prior to the planned departure date of the rig, (iii) positioning the rig around subsea equipment, and (iv) simultaneous operations (SIMOPS) were required to minimize the impact on production operations on the host gas platform.
The Seahorse-1 intervention was successfully completed by utilizing ExxonMobil's worldwide functional expertise in production, drilling and subsea operations. Upon completion of the intervention the well was brought online at 4000 BOPD.
Well Testing by Design: Transient Modelling for Predicting Behaviour in Extreme Wells
Authors: Teng D. , Maloney B. , Mantecon J. C. 
Published: December 2007

Abstract
Offshore rig rates are at an all time high and wells are becoming bigger and longer, in deeper waters and in more complex reservoirs. Well testing in this environment has become more challenging, where well clean-up and flow assurance issues such as slugging and hydrates can significantly extend the planned duration of well tests. The ability to predict and being prepared to deal with such problems by appropriate design of well test equipment can reduce operational risk, minimise safety hazards and environmental impact and potentially save millions of dollars in rig-time.
Traditional well flow software only models steady-state flow. Predicting the transient behaviour of wells, from the unloading of completion fluids until steady state flow conditions are reached, requires specialised software. Dynamic flow simulation software is a proven tool which has been applied for years by facilities engineers for pipeline and slug-catcher design, but its application for well testing is a new practice. Key outputs from dynamic well simulation include slug sizes and frequency, fluid composition and pressure-temperature trends at any time and at any point in the well. Such information enables optimum design so all parameters are within the equipment's allowable operating envelope at any time of the well test operation.
This paper describes how dynamic simulation, using the software package OLGA, was applied to a big-bore gas well with 9 5/8" production tubing. The dynamic simulation study: provided better understanding of well unloading behaviour at different flowrates (by using different choke sizes).assessed the effect of an emergency shut-down (ESD) during a well clean-up operation.defined the minimum flowrate required to cleanup the well (for sizing well testing equipment).
Results from the dynamic simulation indicated that a standard well test package may be adequate for cleaning up this big-bore gas well with 9 5/8" production tubing, though the equipment would be operated at or near its limits and would take quite some time for clean-up. A significantly faster clean-up could be achieved with a high rate well test package at additional cost.
Development Well and Execution Planning in a Complex Subsurface Environment— The Impact of Large and Small Scale Modelling on Well Deliverability
Authors: Philip G. , Twartz S. K. , DePledge J. 
Published: December 2007

Abstract
The Thylacine Gas Field is in the Otway Basin (Offshore SE Australia). The interplay of intra-field faulting and the layered geology mean that there is the potential for a high degree of compartmentalisation. A significant proportion of the reserves are thought to reside in the reservoirs of the Thylacine Sandstone Member, which are poor quality marine sands interbedded with successions of thinly bedded sand-shale and shale. Key to designing wells to achieve satisfactory deliverability was an understanding the distribution of net reservoir in the background of non-reservoir.
The Thylacine development required a low cost, highly efficient development concept to tap these reservoirs. The Thylacine Alpha platform provided a base for drilling of these horizontal wells. The horizontal wells required careful positioning and design to best exploit the resource, due to a mix of the complex structure within the field and significant reservoir quality and distribution uncertainty. To better place the wells, and enhance the outcome predictability for the wells, deterministic and probabilistic amplitude –versus-offset (AVO) inversions were carried out. Simple acoustic impedance models showed improved resolution over the PSDM data, and provided insight into reservoir architecture and geometry and hence confidence in our ability to predict reservoir occurrence for drilling across the field. In parallel, a review of the available core and log data from the exploration/appraisal wells supported construction of a geological model with built-in predictability. The combination of predictive geological model, aimed at improving sub-seismic resolution, and seismic inversion to identify trends in seismic scale reservoir geometry, proved invaluable in both the well planning and execution phases of the project.
This paper outlines the planning phase of the wells and influence of the geological model on resultant well designs and the preliminary outcomes of the execution phase.
Quality Control of Static Reservoir Models
Authors: Spilsbury-Schakel J. A. 
Published: December 2007

Abstract
In the current climate of large numbers of projects, ever shortening cycle times and increasing field complexity, there is a need for rigourous and agreed Quality Control (QC) guidelines for reviewing static reservoir models.
Within Woodside, the assurance process includes a combination of checklists, guidelines, and milestone reviews at predefined steps in the workflow, the latter being a combination of project framing, 10%, 75%, and fully integrated study reviews.
Although each field is different, and each study has its own objectives, common checkpoints are easily identified and can be grouped in general categories such as: study objectives; geological setting and correlation; input data; structural model; layering and log averaging; and facies and rock property modelling (Fig. 1). There are supplemented by the export to dynamic simulators, and comparisons between upscaled and finely gridded properties, including volumetrics. Most software packages provide some sort of audit trails whilst manipulating the data that makes up the static reservoir model.
A set of pointers with respect to general model QC are given, which are as handy as hints and tips for the beginner, and as reminders ("did you think about…") for the experienced static reservoir modeller.
Electrically Powered Drilling Equipment Used in Artic and Harsh Environments
Authors: Kverneland Hege 
Published: December 2007

Abstract
This paper focuses on the benefits with using electrically powered drilling equipment compared with hydraulically solutions in cold and harsh environments. Improved operational performance with higher availability of the equipment, easier installation and maintenance as well as health, safety and environmental (HSE) issues will be discussed. The paper will especially focus on permanent magnet motor (PM-motor) technology, which has recently been introduced in lifting applications and in larger drilling machinery. The possibilities when designing a PM-motor application is related to reduced size and optimized shape of equipment, as well as an enhanced safety aspect in lifting operations.
Calculation of Phase Behavior of Asphaltene Precipitation by Using a New EOS
Authors: Omidkhah M. R. , Nikookar M. , Pazuki G. R. , Sahranavard L. , Emadi M. A. 
Published: December 2007

Abstract
In this study, at first a new equation of state has been presented. Then vapor phase volume, liquid density, saturation pressure and enthalpy of 20 pure components are calculated by this EOS. The obtained results are compared to PR and M-PR equations of state and the accuracy of the new EOS has been approved. In the next step, the Flory-Huggins model has been modified and then the amount of asphaltene precipitation at different ratios of solvent are obtained using the new EOS and M-FH model. The estimated amounts of asphaltene precipitation by this model are compared to the experimental data. This comparison displays that the predicted amount of precipitation in crude oil by our model conform with the experimental data.
An Improved Method for Reserves Estimation
Authors: Thanh Truong Truong 
Published: December 2007

Abstract
Controlling potential risks in Petroleum Industry is one of the most difficult tasks for geologists, reservoir engineers and others. Evaluating oil and gas reserves becomes riskier and less accurate for fields which have complex geologic structure and high heterogeneity. In these cases, correlation relationship between dependent reservoir parameters will be represented better and more exactly with non-linear regression models.
The "box" method is introduced in this research as an improved technique in handling these more accurate non-linear regression models compared to conventional method – Spearman's rank order correlation method – which is available in many commercial Monte Carlo simulators. The conventional method is just correct in uniform and homogeneous reservoirs whereas the "box" method is better for complex and heterogeneous reservoirs.
To get the most accurate estimation of oil and gas reserves, a computer program using the above improved technique along with Monte Carlo simulation method was written. Some randomly generated data that were similar to data from a specific heterogeneous reservoir were also considered. And exhaustive simulation runs were performed to compare the results from written computer program to those from a commercial Monte Carlo simulation package. It was seen that their outputs were different due to different methods used.
Regarding such exactly estimated amount of oil and gas from written computer program, project designing team planned field development more accurately and efficiently. This very important factor led to a successful production project.
New Experience in Monofilament Fiber Tandem Sweeps Hole Cleaning Performance on Kharyaga Oilfield, Timan-Pechora Region of Russia
Authors: Bulgachev R. V. , Pouget P. 
Published: December 2007

Abstract
Drilling the 12 1/4" sections for the Kharyaga oilfield in the Timan-Pechora region of Russia has always been considerably complicated by wellbore instability and hole cleaning issues. These issues have been most serious when drilling through Triassic and Permian shales, sandstones, argillites and silts, followed by drilling Carboniferous limestones and dolomites. Unstable formations sloughing and packing off, wash outs and severe caving has resulted in many problems including drill pipe pack-offs, high torque and drag, the need for additional reaming operations, and difficulties in reaching bottom with casing.
Fluid treatments of swelling shales with chemical inhibitors helped considerably with shales hydration, but the problem of caving and packing off still persisted. High angles (up to 52.8°) and long section lengths (up to 2,707 m) aggravated the problems. The key remedy was determined to be effective hole cleaning. Cleaning efficiency of different types of sweeps was studied during drilling of 10 Kharyaga wells. Sweeps were pumped on a regular basis in drilling intervals of 100, 150, 200 and 300 meters, prior to pulling out of hole and when indications of packing off had been observed.
Pumped cleaning sweeps included high-viscosity or high-density single sweeps; tandem sweeps (low-viscosity following by high-viscosity or high-density sweeps); and sweeps with special additives (carbon-based LCM material or innovative monofilament fiber sweeping agent). Also, special attention was given to combined tandem sweeps, which are low-viscosity sweeps treated with a monofilament fiber sweeping agent followed by a high-density sweep (sometimes treated with carbon-based LCM material).
Investigation of different sweeps performance showed that the best hole cleaning results for Kharyaga field wells were achieved by circulating combined tandem sweeps, which are low-viscosity sweeps treated with a monofilament fiber sweeping agent followed by a treated or untreated high-density sweep.