bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interference Testing: A Significant Part of the Mangala Appraisal and Reservoir Characterization Programs
Authors: Tandon Rohit , Beliveau Dennis 
Published: March 2008

Abstract
Mangala is currently the largest discovered oil field in the Barmer Basin of Rajasthan, India, with a STOIIP of over 1 billion barrels contained in the stacked clastic fluvial reservoirs of the Fatehgarh Group. The field was discovered in January 2004 and a fast-track appraisal program followed, involving the drilling of eight more wells and a host of data acquisition activities in 2004-2007. Production startup under waterflood is planned for 2009, with an initial plateau production rate of ~100,000 bopd. As there is no analog Fatehgarh production anywhere else in the country, multi-well and single-well interference tests provided essential large-scale areal and vertical reservoir connectivity data that helped to ground the geologic and reservoir models that were the basis of the field development plan.
Areal interference tests were conducted by recording a baseline MDT pressure trace throughout the entire reservoir section in the observation wells. After production/injection began in the source well, additional MDTs were conducted in the observation wells to monitor pressure changes throughout the reservoir section, thus providing both an areal and a vertical measurement as to how the pressure response spread. An important test was carried out by producing Mangala-1 and monitoring pressure responses in three adjacent wells that were 300 - 1,500m distant. This test demonstrated excellent areal communication and a fair degree of vertical communication through the reservoir.
A second key areal interference test was carried out in conjunction with a water injectivity test in Mangala-2 while observing the pressure response in Mangala-1 and Mangala-4. Although a response was observed in Mangala-1 at a distance of 2,700m, no response was observed 700m away in Mangala-4, confirming that the shale correlated between Mangala-2 and Mangala-4 is a barrier to fluid flow. Finally, a single-well vertical interference test was carried out in Mangala-5; this demonstrated that a typical shale layer that occurred between the producing and observation zones in the well was actually of limited areal extent, and provided a "match point" for the geologic model.
This paper explains the design, operations and results interpreted from each test and how these results were key factors in geological modeling of the field and planning the initial development concept.
Magnetic Shielding During MWD Azimuth Measurements and Wellbore Positioning
Authors: Amundsen P. A. , Ding S. , Datta B. K. , Torkildsen T. , Saasen A. 
Published: March 2008

Abstract
Magnetic contamination of the drilling fluid may contribute significantly to errors in directional surveying of wellbores. Such contaminations shields the field measured by the magnetic sensors in MWD directional tools. The resulting error often exceeds typical sensor uncertainties, and so the accuracy of the inferred wellbore position is severely degraded. Although the magnetic interference can be reduced by careful attention to procedures for transport, pumping and handling of drilling fluids and their associated additives, the problem has not yet been eliminated.
In order to understand the magnetic shielding effect in a well-defined setting, we have initiated a series of laboratory measurements, where magnetic material of known properties are added to a well defined non-magnetic drilling fluid, and measuring the resulting magnetic shielding with a fluxgate magnetometer immersed in the fluid.
In our experiments, powdered magnetite was added to a mixture of xanthan gum in water to obtain a mixture of nominal magnetic susceptibility typical of drilling fluids containing metal from pipe wear and erosion. Immediately after stirring, the vertical component of the Earth's magnetic field inside the liquid was measured and found to be significantly damped. Without touching the system, the field was subsequently logged. It was found to continue to decay for the next hour, or so, reaching a fairly sharp minimum. The magnetic field then started to increase slowly and irregularly again over the next few days. The observed effect, combined with analysis of directional data, can explain errors encountered in directional surveying.
Analyzing Geomechanical Effects while Drilling Sub Salt Wells through Numerical Modeling
Authors: Mackay F. , Inoue N. , da Fontoura S. A. B. , Botelho F. 
Published: March 2008

Abstract
Santos Basin is one of the most promising basins of Brazil, recently it was discovered light crude oil of 30° API (American Petroleum Institute), this reservoir of high productivity is located below a salt layer of two thousand meters (6561,7 ft) of thickness. Salt also known as an evaporite rock is found in many hydrocarbon basins around the world. Evaporites are sediments formed initially from minerals dissolved in water, the most common are: halite, gypsum, and anhydrite. These minerals are found in areas that passed by a geological time of high evaporation or precipitation. Evaporites in general have the structure of a dome, formed when a thick layer of salt found in the bottom begins to crossover superior layers vertically; this process takes millions of years. The presence of saline structures takes into favorable conditions for creating a trap for hydrocarbons, increasing the success of probability in oil and gas exploration. In salt drilling the main problem is the closing of the well or known as squeeze or salt pinch, this phenomenon provokes the imprisonment of the drillstring also known as stuck pipe. Evaporite rock behavior is defined through a creep model. The creep model is the term used in the bibliography to define the tendency that a material has to move or to deform permanently to relieve stresses. Strains take place due to extended levels of stress; this stress is less than the rupture stress. In this matter it was chosen a numeric tool to simulate the behavior of salt drilling and the effects that this will have due to the overburden stress and drilling fluid pressure. This tool is a commercial program of finite elements in 3D (three dimensions). The objective of this work is to determine the effect of the fluency (creep) in salt during and after the drilling of the well, through numeric simulation. At first it is shown a validation of the commercial finite element program comparing results from literature and then it is shown a simulation of a 3D vertical salt wellbore.
Highly Flexible Mud-Pulse Telemetry: A New System
Authors: Klotz C , Wassermann I , Hahn D 
Published: March 2008

Abstract
Mud Pulse Telemetry (MPT) systems enable the MWD/LWD companies to transmit to surface valuable directional and formation data during the drilling process. This data is used to optimize the drilling process, making drilling operations more cost efficient and allowing the drilling of more complex wells.
The major factors limiting MPT data rates include maximum downhole signal strength, signal attenuation, surface induced noise and surface piping induced signal reflections. Most of these are not predictable, not arbitrarily adjustable and potentially change their properties during the course of data transmission. To achieve maximum possible data rates under those challenges, telemetry systems must be highly flexible, both downhole and at the surface receiver. Downhole, the transmission tool should be able to support different signal types and different signal frequencies to optimally use the transmission channel (the mud filled pipe bore).These signaling parameters should be changeable during operation. On surface, sophisticated noise processing should be employed to increase the overall system Signal-to-Noise Ratio (SNR).
This paper describes a new system for mud pulse telemetry that supports two signaling types, different signal modulations and various signal frequencies. The new system comprises a novel mud pulser and a digitally controlled, automatically adjusted surface system. With the downhole mud pulser in the borehole, the new system allows the optimization of the mud pulse telemetry process for maximum MWD/LWD information at surface while drilling the well.
This paper introduces the system and gives details on how the achieved high speed data rates of the new telemetry system have helped to deliver real time answers while drilling.
New Generation Rotary Steerable System and Pressure While Drilling Tool Extends the Benefits of Managed Pressure Drilling in the Gulf of Mexico
Authors: Njoku Johnson Chydi , Husser Alex , Clyde Robert 
Published: March 2008

Abstract
As hydrocarbon basins mature, reservoir pressure depletion caused by hydrocarbon production leads to severe pore pressure/fracture gradient anomalies that can reduce an otherwise sufficient mud weight window significantly. At the same time, reentries involving slim-hole sidetracks incur high annular losses that further widen the gap between equivalent static and circulating densities - ESD and ECD. In this situation, it is not possible to drill using normal overbalanced methods. The risk of formation fracturing and fluid losses, fluid influxes, and wellbore collapse would far outweigh the reward of increased production. The effective variation of static and circulating densities must be minimized. A major project in the Gulf of Mexico posed such a problem. Managed pressure drilling (MPD) was adopted as the solution to manage a tight hydraulic window and effectively drill reservoirs which would have been extremely challenging using conventional drilling methods.
Traditional directional drilling with a positive displacement motor would normally create more pressure balance complications under a MPD environment due to the continuous fluctuations to the ECD when the motor is in sliding or steering mode.
This paper outlines how new generation rotary steerable systems coupled with the interpretation from a downhole real time pressure while drilling sensor was engineered to maximize drilling performance for a directionally drilled well in MPD environment.
This paper will also discuss the case histories and lessons learned and thoroughly review the range of opportunities these technologies have created in the maturing areas of the Gulf of Mexico.
Cased-Hole Sonic Technique for Stress Determination and Optimization of Oriented Hydraulic Fracturing Operations
Authors: Klimentos T. , Ghosh A. , Sagar R. , Nayak J. P. , Hotta A. , Jantasuwanna P. , Singh R. N 
Published: March 2008

AbstractShear-wave anisotropy gives a measure of stress anisotropy intensity and the associated fast-shear azimuth gives the maximum horizontal stress direction. This information is very useful in optimizing oriented hydraulic fracturing operations, wellbore stability, sand management, well placement and other applications.In open holes, this fracture or stress induced anisotropy can be effectively measured using cross-dipole sonic logging.However, determining shear-wave anisotropy in cased holes has been hindered by two factors. The first is the concern of the effect of casing and cement on the cross-dipole measurement, and the second is the lack of an effective device to measure the tool's orientation inside casing.This paper presents a solution to this problem using recently developed sonic logging technology in conjunction with Gyro data acquisition.Cased-hole Sonic and Gyro data were acquired in four wells for oriented fracturing optimization over zones with no or poor production. Gyro data was used as a reference for the sonic waveform rotation in order to determine the fast shear azimuth direction and maximum horizontal stress orientation. The cased-hole sonic monopole and dipole data quality was excellent, even over double casing sections. It was found that the reservoir sands are anisotropic; however, the shear-wave anisotropy magnitude is low.This is the first ever cased-hole Sonic + Gyro acquisition survey in India. The results showed that we can now confidently determine shear-wave anisotropy behind casing with the new sonic technology, even in low anisotropic formations with accuracy down to ~1%.The Sonic derived horizontal stress information was then used effectively to optimize the oriented fracturing operations. Low tortuosity while fracturing in the studied wells proved perfect direction for oriented fracturing. After fracturing, the production gain was substantial.Therefore, such cased-hole sonic technique can be useful in generating stress-maps of the reservoirs, which can then be used in various applications, such as oriented fracturing, sand control, reservoir characterization, fracture evaluation behind casing, wellbore stability and well placement.
Utilizing Remote Collaboration and Visualization Technologies in a Collaborative Work Environment to Connect Indian Experts With Worldwide Operations
Authors: James Simon , Gullhav David 
Published: March 2008

Abstract
In a world where oil & gas technical expertise is in increasingly short supply companies which can tap pools of centrally located experts, to remotely and proactively support their distributed asset portfolio, will gain competitive advantage. Making maximum use of a diminishing technical skillpool is critical to ensuring sufficient expertise in assets where the workforce can not always include all the necessary specializations.
Shell Technology India plan to utilize advanced remote collaboration and visualization technologies as an enabler for ensuring connectivity between our Technology Centre in Bangalore and our operations globally, both upstream and downstream. These technologies will be housed in a purpose built Collaborative Work Environment, unique in India, which is linked to a network of such environments in our assets and other Technical centres worldwide. This close connectivity, with Shell Technology India forming part of a "virtual" asset team, is allowing us to develop new business models involving redistribution of key operational and project-based tasks to Bangalore.
The Collaborative Work Environment allows us to view real-time operational data from our worldwide production; drilling; refining and manufacturing operations, in surveillance rooms in Bangalore. Subject Matter Experts in Bangalore can then offer technical advice directly to asset teams during operational activities. Other functionality includes virtual reality viewing of subsurface & facilities 3D models, and "information walls" where multiple sources of information can be displayed simultaneously to support multidisciplinary decision-making.
Future developments are planned to include the offering of 24/7 Operational Support Services to assets in areas such as ensuring the availability of the technical infrastructure (communication networks, real-time data management systems), or routine surveillance tasks. Also "bringing operational work experience to Bangalore" by offer state-of-the-art experiential training in drilling, facilities and process control.
Cleat Characterization in CBM wells for completion Optimization
Authors: Ali Mohammad , Sarkar Arpana , Sagar Rajiv , Klimentos Theodore , Basu Indrajit 
Published: March 2008

Abstract
Fracture systems comprise the primary flow path within coal bed methane (CBM) reservoirs. These fractures, also called as cleats, define the reservoir character and fluid flow potential. Cleats are commonly mutually orthogonal and occur perpendicular or at very high angles to the bedding. The standard suites of logs, such as density/neutron, gamma ray and resistivity, define some of the petrophysical properties of the coal layers, but the nature and extent of cleating often remains poorly defined from these logs and by using standard log evaluation methods.
A CBM well may often penetrate multiple reservoir zones (seams) and properly characterizing the cleats will help in determining which of these seams should be completed to optimize the production. In addition, through better seam characterization, a technical basis for a preferred completion method (horizontal well, hydraulic fracture, open hole or cavity) can be ascertained.
High cleat density in coal seams is an essential requirement for better fluid flow in CBM reservoirs. The primary cleat direction and its relation with the in-situ horizontal stress directions define the fluid flow potential through the cleats and such information can be used to select the completion method.
In this study, full waveform sonic log with monopole and flexural waveform and high resolution electrical image log data from CBM wells in Jharkhand, India, have been integrated, in a bid to identify the ideal candidates for completion. Coal seams for best production potential are identified through cleat density characterization. In this paper, we show how compressional and shear slowness variation and Stoneley waveform transmission coefficient analysis are used to interpret the variation in cleat density. The cleat density is further validated from the fracture analysis using micro-resistivity image logs.
Cleat orientation can be determined from the detailed structural evaluation of the fractures seen in the high resolution resistivity image. Maximum horizontal stress direction has been computed from acoustic anisotropy evaluation. This maximum stress direction and cleat orientation have been integrated to identify seams that will have better deliverability of fluids.
In this paper we provide a guideline for selecting a completion methodology in coal bed methane wells based on cleat density, stress direction, cleat orientation and wellbore stability.
Systematic Diagnostics and Real Time Reservoir Monitoring in a High GOR Horizontal Well To Detect the Source of Gas: A Case Study in Panna Field, Western Offshore, India
Authors: Mishra Gaurav , Prakash Swaminathan , Prakash Roshan 
Published: March 2008

Abstract
The Panna field, located offshore the western coast of India is a carbonate reservoir with a thin oil rim (~20m) sandwiched between a gas cap and a large bottom aquifer. The field comprises of two main layers – ‘A’ zone gas cap and ‘B’ zone which is the main oil producer, separated by an interface. As the vertical/horizontal permeability ratio is high (~1) this reservoir is highly susceptible to coning problems. Horizontal multilateral wells were drilled in ‘B’ zone to achieve maximum reservoir contact with minimized gas coning. These wells are equipped with permanent downhole gauge to monitor conditions downhole in real time and auto gas lift to use energy from the gas cap to lift fluids from the oil reservoir when required in future. However, in first such well unwanted high gas production raised doubt on the completion integrity and on the possible communication between two zones. This necessitated a thorough troubleshooting to detect the gas source for corrective action afterwards.
This case study presents the methodology applied in detecting the source of the abnormal high gas production using Production Logs & Permanent down hole gauge using auto gas lift diagnostics. The diagnosis, carried out in phases, enabled us to pinpoint a highly unlikely source by removing all other possibilities such as leaking Auto Gas Lift, communication between zones, seal bore integrity failure.
This was confirmed by production logs which indicated a leak in Full Bore Isolation Vale vent ports and confirmed that Auto Gas Lift is functioning properly.
These findings were significant as the well was saved from a possible workover or sidetrack and production was enhanced as well.
Cement Slurry Design to Prevent Destabilization of Hydrates in Deepwater Environment
Authors: Ravi Kris , Moore Seth 
Published: March 2008

Abstract
Hydrates present challenges to drilling, cementing, and producing in deepwater environments. If the hydrates are destabilized during well operations, gas or solids could rise to the surface and create problems. Therefore, there is a compelling need to prevent destabilization of hydrates from drilling to producing operations in the life of the well.
The volume of cement slurry in the surface casing is great because of the large annulus, and this slurry volume results in a great amount of heat generated during slurry hydration. Further, during production hydrocarbons could increase the temperature of the surrounding formation. These factors could destabilize the hydrates.
Cement slurries are designed to lower the heat of hydration while meeting or exceeding the other properties needed for successful deepwater cementing. Heat of hydration is reduced by a factor of more than two when compared to the conventional cement slurry design. The improved cement slurry designs lower considerably the thermal conductivity of the set cement sheath.
Laboratory tests designed to measure and optimize the heat of hydration are discussed and field implementation of these slurries and results are presented. Results presented in this paper should help the industry construct and produce wells without destabilizing the hydrates, thus promoting well safety and economics.
BP's Subsea Developments: Past Successes and Future Challenges
Authors: Botros Fikry , Noel Cornelia , Brookes David , Perry Robert 
Published: March 2008

Abstract
BP's successful track record in subsea developments dates back to the 1970's. Since that time, BP has developed about 180 subsea wells which are producing some 800,000 bpd of oil and gas. These developments have endowed BP with unique knowledge and experience in the development and operation of an eclectic mix of subsea installations worldwide. The envelope of our existing developments cover water depths exceeding 2500m, shut-in pressures of 1000 bars combined with 135°C temperatures, and tied back to all major types of floating hubs at offset distances of up to 90km.
The next wave of deepwater and subsea projects will require the development of reservoirs with compound issues: HPHT (1400 bars, 177°C), heavy crude, low permeability, low pressure among others. Some of these reservoirs are located in remote regions with few offshore host facilities and/or ecologically sensitive environments with extreme climatic swings.
This paper presents an overview of BP's many milestones in subsea projects over the years. The intent is to underscore our achievements and capabilities in project development and operations, enumerate the challenges facing the next generation of subsea developments, and outline the company's approach to technology development to ensure success.
Need for New a Recruitment Strategy
Authors: Parmesh Manoj 
Published: March 2008

Abstract
Recruitment has become the most challenging Human Resource function across all industries today. For a specialized vertical like Oil & Gas, the challenges are still enormous. Recruitment in Oil & gas industry is getting more and more complicated as the environment in which the upstream industry operates is very global.
Why do we find it difficult to attract new talent?
There are three main reasons for this. Firstly, the industrial activity across the world is at an all time high, which has in turn created more jobs thus making availability of personnel very difficult. Secondly, the industry has not exactly attracted a lot of people over the last twenty years for factors such as industry cyclicality, new technology, public perception etc to name a few. Thirdly the baby boomers generation is approaching retirement and the younger generation is not in enough numbers or experienced enough to fill the gap.
Need for a new strategy
Considering the above realities, there is a dire need for organizations in the industry to come up with a completely new recruiting strategy to ensure that its aggressive growth targets are not choked by the issues surrounding virtually all companies alike in the industry. The need of the hour is to shift from a traditional reactive recruiting towards a more proactive recruiting, clearly understanding the various factors of the job market. This recruiting strategy always revolves around four aspects.