bluuebunny/crossref_metadata_2025 huggingface dataset:
An Integrated Transport Model for Ball-Sealer Diversion in Vertical and Horizontal Wells
Authors: Li X. , Chen Z. , Chaudhary S. , Novotny R. J.
Published: December 2007

Ball sealer diversion has been proven to be both an effective and economic way to selectively stimulate low permeability oil and gas reservoirs in hydraulic fracturing and matrix acidizing treatments. However, the design and implementation of a successful ball sealer diversion treatment is still a challenge. Often the designer depends on experience, and lacks the knowledge of accurate ball transport and sealing behaviors. An integrated model for selecting operating factors such as fluid and ball properties, as well as predicting the ball sealers transport and hydraulic behavior prior to pumping is needed for optimizing the stimulation process.

In this paper, an integrated transport model is presented to describe the relationships among the ball sealer transport sealing behavior, wellbore deviation, wall effect, perforation density and size, fluid properties, pumping rate and ball properties. In addition, the smoothness of ball, perforation phasing, and velocity profile inside the wellbore during ball seating are also taken into consideration. Recommendations are provided for determining the number of ball sealers per job for either single or multiple stage treatment, the designed pumping rate, and the physical properties of the fluid and ball sealer. A hydraulic analysis model is presented for the overall fluid dynamics starting from surface, through wellbore, to reservoir. This analysis describes the effects of reservoir condition, pressure drop on perforations, and actual sealing efficiency on the surface treatment pressure profile. This paper will investigate the effects of the diversion factors on the ball transport behaviors such as transport time, ball sealer efficiency and surface pressure.
Breakthrough Drilling Performance in Horizontal Deep Gas Wells with Application of Geo-steering Technique in Saudi Arabia
Authors: Thomas S. , Al-Thuwaini J. , Petrick M. , Nwabor D.
Published: December 2007

Saudi Aramco attempted to drill horizontal deep gas carbonate wells without utilizing the Geo-steering technique in Hawiyah/ Uthmaniyah (HWYH/UTMN) field. In both 8-3/8" and 5-7/8" horizontal sections, much time was lost due to low ROP, sidetracks due to drilling in an unwanted pay zone and a stuck BHA, drilling with TCI and PDC bits (originally designed for vertical application).

A new approach was required to deal with this problem. The reservoir engineers and drilling engineers, together with service companies, analyzed each problem in detail and found the solution, utilizing LWD/Geo-steering technique. An improvement in casing design led to reduced MW across the pay zone. A geo-mechanical study was conducted and implemented its recommendation of drilling in the direction of maximum horizontal stress. This approach utilized PDC bits designed for horizontal drilling. This approach reduced drilling costs for over five laterals; compared to the previous five laterals in this carbonate reservoir (costs do not include the additional bits and pipe conveyed logging in these wells).

Utilizing the Geo-steering Technique in the carbonate reservoir increased the length of pay from 6,360 ft to 15,400 ft, an increase of 142% over a five-well average. It reduced the number of days required to drill five laterals from 364 days to 129 days, a reduction of 65%. Total lateral footage drilled for these five laterals reduced from 24,251 ft to 19,898 ft, a reduction of 18%. The average ROP improved over five wells from 6.11 ft/hr to 12.67 ft/hr. The average footage drilled per day increased from 66 ft/day to 154 ft/day and average number of bits used per well reduced from 13.4 bits to 3.6 bits per well. No sidetrack was required. One of the recent wells was drilled in record time for a HWYH/UTMN horizontal well and was also the longest single-lateral horizontal well in the field. One of the 8-3/8" PDC bits achieved record performance by drilling 4,475 ft in 261.5 hrs with an average ROP of 17.11 ft/hr, representing one of the longest intervals drilled by any 8-3/8" PDC bit in Khuff-C carbonate reservoir.
The Material Issues Involved in the Discussion Surrounding the Virtues of the SPE/WPC Definition of Proved Oil and Gas Reserves vs. the Corresponding Definition Set Out by United States Securities and Exchange Commission (SEC)
Authors: Cline W. B. , Rhodes B. C. , Hattingh S. K.
Published: December 2007

Among the more contentious issues discussed within the oil & gas industry recently are: Are the United States Securities and Exchange Commission (SEC) definitions of Proved oil and gas reserves obsolete, too narrow and/or unrealistic for today's oilfield technology?Are the SPE/WPC definitions of Proved oil and gas reserves much more realistic and responsive to today's comparable reporting needs?Has the meaning of the word ‘Proved' changed over the last twenty-five years?Has the meaning of the expression ‘Reasonable Certainty’ changed over the last twenty-five years?

The contention here is that the answers to each of these four questions is ‘No’. This paper advances the idea that there are no material differences between the Proved oil and gas definitions promulgated by the two organizations if the original common cornerstones are honored within the true spirit of the words engaged in those definitions.

The allegation that the SEC definitions for Proved oil and gas are in some way out-of-date in terms of the application of modern oilfield technology is examined and found to be without legitimate foundation. The distinctive variation between the two organizations is discussed; the SEC as a regulatory authority with responsibilities for ensuring comparable reporting by listed corporations within its jurisdiction versus the SPE as a Technical Society without such responsibilities or the structure for offering guidance regarding definitional compliance.

As the ‘interpretation drift’ in the application of the SPE/WPC Proved reserve definition continues unabated, the search for an International Standard by other organizations (particularly the United Nations) only further complicates the matter. The question is posed as to whether the lack of proactive contributions in this regard from the SPE, as an organization, places the very integrity of the Society's broader reserve definitions at stake. The SPE membership are reminded that very few years ago, the SPE/WPC/AAPG definitions were very credibly put forth for adoption as the essential International Petroleum Industry Standard.
Real-Time Asset Management: From Vision to Engagement—An Operator's Experience
Authors: Unneland T. , Hauser M.
Published: December 2007

The Digital Oil Field is rapidly gaining attention within the oil and gas industry. Several oil and gas operators are working to develop their vision for an oil field of the future, testing new technologies, setting up programs and participating in industry events. The vision is an integrated approach allowing more real-time control of asset management. Many different names are used in the upstream industry to describe this trend; Smart Fields, Digital Oil Field, Next Generation Oilfield, Field of the Future, e-field, Instrumented Field and Intelligent Energy. However, there is still uncertainty as to what needs to be done and what value it will actually bring to the industry. Several operators and service companies are transitioning from the initial envisioning and abstract phase to projects creating measurable value for the company. In this paper, Chevron's efforts within the Digital Oil Field domain, including concept, business case, corporate governance, technology development, partnerships, deployment and field experience are presented.
Simple, Robust NMR-Based Indicators for Detection of Hydrocarbon Gas or Oil, Borehole Contamination, and Vugs
Authors: Chen S. , Munkholm M. , Hursan G. , Georgi D. , Gillen M.
Published: December 2007

NMR logging techniques have proven to be useful tools for a variety of formation rock properties and fluid typing applications. In the last decade, numerous improvements have been made both to multi-frequency NMR logging instruments and to data acquisition methods that have significantly enhanced the data quality and expanded the NMR logging applications envelop. On the other hand, these more versatile acquisition methods collect a large quantity of data that may seem overwhelming to most non-expert NMR users. To overcome the complexity of NMR logging and facilitate the wellsite decision-making, we have developed a number of simple, robust NMR log-based indicators for identifying hydrocarbon gas or oil, for detecting borehole rugosity contamination, and for recognizing vugs in carbonate reservoirs.
Reservoir Simulation and Reserves Classifications—Guidelines for Reviewing Model History Matches To Help Bridge the Gap Between Evaluators and Simulation Specialists
Authors: Rietz D. , Usmani A.
Published: December 2007

As the scrutiny on oil and gas reserves continues to increase, the subject of evaluating reservoir simulation models has come to the forefront. Regulatory bodies, such as the U.S. Securities and Exchange Commission, do not provide detailed criteria on the use of reservoir simulation models in the reserves estimation process, other than their stated position that the model must have a "good history match". A great deal of high quality, highly technical research has been conducted in the field of history matching and of late in "automatic" history matching, and the paper reviews some of this research. While much of this research is useful, it is not clear that any particular quantitative assessment can be made of history match quality, or if such a method really helps to understand the applicability of the history matched model. It is easy to understand why reservoir simulation specialists and reserves estimators may be at odds as to the use and utility of a particular model. It is well recognized that, in general, only a limited amount of time is available to review models; thus, only a fraction of the time devoted to the original model construction can usually be devoted to the review process.

The authors have been on both sides of this dilemma, and this paper is intended to provide some suggestions for a systematic review of models (for whatever ultimate use) and start a dialogue to discuss how history matches should be evaluated with respect to reserves. It is noted that, for the most part, model reviews do not need to address whether a model is "perfect" overall, rather a review should address whether a model is fit for a particular purpose. The authors propose that the applicability of the model, and the quality of the history match can always be qualitatively assessed if one views the model as an analogy for a particular property. Therefore, the "analogy" approach suggested by the authors provides a specific methodology for incorporating simulation model results in the reserves estimation process.
A Well Test for In-Situ Determination of Relative Permeability Curves
Authors: Chen S. , Li G. , Peres A. , Reynolds A. C.
Published: December 2007

We propose a novel well-test for in situ estimation of relative permeabilities under two-phase (oil-water) flow conditions. The test consists of three periods, (i) injection of water into an oil reservoir operating above bubble point pressure, (ii) a falloff test and (iii) a producing period. The producing period is critical as it yields production data that reflects changes in sandface mobility and thus is highly sensitive to the parameters used to model relative permeability curves, whereas, our results indicate that injection/falloff pressure data by themselves are not as reliable for defining relative permeability curves. We have developed optimization code based on the Levenberg-Marquardt algorithm and coupled it with a commercial reservoir simulator to obtain a procedure for data analysis where the reservoir simulator is used as the forward model. By matching data by minimization of a weighted least squares objective function, we generate estimates of absolute permeability, relative permeabilities and the well skin factor. We show the method can be applied with either power law models or B-splines. We introduce a variable transformation that can be used to ensure that the estimated relative permeabilities are monotonic and concave up when B-splines are used.
WPCI Treatments in a Deep HP/HT Production Hole Increase LOT Pressures to Drill Ahead to TD in a Gulf of Mexico Shelf Well
Authors: Traugott D. , Sweatman R. , Vincent R.
Published: December 2007

This paper covers two wellbore pressure-containment integrity (WPCI) treatments that substantially increased the pressure- containment integrity in 852 ft of open hole in the last sidetrack for the production hole section. This ultimately saved having to set pipe early, which could have jeopardized the commercial discovery of a lower gas sand. Earlier side tracks attempted unsuccessfully to bypass the loss/flow problems that would not allow drilling ahead and increasing the 18.0-lb/gal mud weight (MW) to drill into a high-pressure zone on adeep, high-pressure/high-temperature (HPHT) well in the western Gulf of Mexico shelf offshore Louisiana. Various lost-circulation material (LCM) treatments were used with no success increasing the hole's pressure containment.

The WPCI treatments raised the leakoff test (LOT) across the entire 852 ft of open hole up to 19.1 lb/gal equivalent (ppge) vs. the lower LOT of 18.3 ppge before the first WPCI job. LOTs were performed before and after each of the two WPCI treatments to measure improvement in the hole's pressure-containment integrity. This LOT data helped prove that apparent fracture gradients can be simultaneously increased in multiple numbers of layers and different types of weak formations exposed in long, open holes by inducing near-wellbore, flexible stress cages created from WPCI treatments.1-4 This can then allow use of increased MWs and drilling pressures to prevent excessive gas influx from high-pressure sands without lost circulation (LC) in adjacent weak zones.

The paper discusses the WPCI treatment design and job procedures, including treatment optimization by the analysis of data from openhole wireline/logging while drilling (OHWL/LWD) logs, cuttings lithology, fracture-seal location indicators (torque on bit [TOB]/weight on bit [WOB]), and before/after LOT pressures. Real-time operations5 also described allowed remote expert analysis and support for wellsite personnel to (1) interpret formation characteristics for optimized treatment design and (2) analyze treatment pressure/rate data for selected placement of WPCI sealants.
Offshore Run: A Model of Working and Living in Harmony
Authors: Khantong A.
Published: December 2007

The offshore environment is a unique working place. Workers must live and work together for at least 14 days or more. They are faced with long working hours, shift work, and the feelings of being separated from their families and friends. There can be boredom when daily assignments become routine. Acknowledging these facts, Unocal Thailand Health and Medical Services has organized a special program to harmonize living and working offshore to create a better working atmosphere. The Offshore Run, a special charity event sponsored by the company, not only promotes healthy exercise but also provides an opportunity to join together to achieve a common milestone. This allows employees to demonstrate their unity, commitment and spirit for a worthy cause.
A Common Approach to Accessing Real-Time Operations Data: Introducing Service- Oriented Architecture to E&P
Authors: Gregovic R. M. , Foreman R. , Forrester D. , Carroll J.
Published: December 2007

Due to the high degree of diversity in which real-time operations and production data is stored and distributed within BP-indeed, within almost any large oil company today-E&P professionals who carry out similar activities in different assets or business units must access data in distinctly different ways. Therefore, any attempt to implement a "standard" application requires IT personnel to have intimate knowledge of the underlying data sources within every asset. Scale up and rapid adoption across multiple assets of either new or proven digital technologies is extremely difficult as well, due to disparate IT architectures.

The challenges and complexities caused by lack of standardization have fostered rampant development of local, costly, and time-consuming "point solutions"-typically "hard-wired" point-to-point connections between each data source and each application, whether proprietary or commercial. This familiar approach to integration seriously compromises the organization's technical flexibility in the face of ongoing business changes. As a result, business units within BP have increasingly requested standardized digital solutions that would enable seamless data flow among different classes of E&P applications and business processes.

The Real-Time Architecture Project (RTAP), initiated in 2003, now provides a common approach for all assets to access real-time production operations data. It is built around a simple connection technology capable of integrating a wide range of tools such as production reporting, real-time visualization and active alerting with new or existing data sources of many kinds. RTAP utilizes "Web Service" technologies, which create highly flexible interfaces based on established and emerging Internet standards.

BP's ultimate goal is to implement a common, standards-based architecture for data access and integration, replacing the large number of custom, proprietary interfaces currently in use. Since launching RTAP two years ago, significant progress has been made toward this goal, with the intent of expanding the current implementation to a next-generation "Service Oriented Architecture" (SOA) in the near future. This paper provides a review of the RTAP project's origins and development efforts, BP's rationale for this approach, a high-level, non-technical description of the solution, an overview of associated business benefits, and a case study validating the approach. The potential for Service Oriented Architectures in E&P-which represent a paradigm shift in how IT is developed and deployed-and the need for industry standards in this exciting new area, will also be discussed.
Human Factors—Health and Safety as a Priority in Design Experience from the Norwegian Petroleum Industry
Authors: Høivik D. , Throndsen T. I.
Published: December 2007

Human Factors (HF) currently have a high focus in the Petroleum Industry in Norway. The ultimate purpose of HF methods and knowledge is to establish a work situation that is efficient and safe and promotes the health of the workers. HF methods and knowledge contribute to create an efficient and reliable interaction between man, technology and organisation. A systematic HF analysis in design is one of the efforts contributions to improve HSE results.
The Good Practices in HS&E Management of Contractors
Authors: Lang K. , Burnett N. , Allan D. , Fergusson A.
Published: December 2007

Contractor Management is a key issue for operators to ensure effective Health, Safety and Environmental performance at their drilling and production locations. However, operators managing contractors working for multiple clients, at multiple sites face differing styles and requirements, yet must maintain a high performance safety culture across their activities in accordance with their own policies and requirements.

This paper describes one contractor's perceptions of the HSE Management Systems used by UK North Sea operators. The methodology employed in the study included questionnaires and interviews to determine perception of operator methods and effectiveness. This sought to identify the following. The key drivers in the operators intent in managing contractor HS&EWhat the Operator did to assist contractor HS&E effortWhat the Operator could have done better to improve contractor HS&E effort andWhat the Operator could have done additionally to improve contractor HS&E effort.

Data from personnel at various points in the supply chain were collected. Personnel included senior managers, account managers, field co-ordinators, wellsite engineers and HS&E Managers. The information and experience provides an insight into working together to improve HS&E.

The underlying mechanisms and behaviors within the management systems are discussed. Contractor perception of best practice and improvement opportunities is described. It is anticipated that this is of value in establishing and developing systems to manage contractors and to contractors who seek to work effectively with clients.
Real-Time Basin Modeling: Improving Geopressure and Earth-Stress Predictions
Authors: Standifird W. , Matthews M. D.
Published: December 2007

Basin modeling is an effective tool for pore pressure prediction. A model that can be updated as new data is acquired can provide a Look Ahead prediction that may be valid for several thousand feet ahead of the bit.A new modeling program is described that has proven effective both in pre-drill analysis and in while-drilling situations for a variety of geologic regimes. In the recently completed DEA 119 Phase 2 study, pressure gradients were predicted to less s than 1 ppg for the whole well in 62% of blind test analyses. In numerous wells, real time updating of the basin model has proved effective at narrowing the envelope of pore pressure and Earth stress uncertainty ahead of the bit.

The model utilizes conventional compaction principles derived from seismic and/or well gradient logs as calibration. It combines this information with geologic-based information (ages, thickness, porosity and lithology) to predict the geopressure environment that will be encountered by the well.

As the well is drilled, new information becomes available that will either confirm or refute the original geopressure prediction. This new data is well-specific and can be used to update the basin model. The data ahead of the bit still contains all of the information that is known about the area and has not been changed by the addition of the real time data. Adjusting the model with the newly acquired data will therefore reduce the envelope of uncertainty that existed in the original model and update the prediction with the new information. This updating is performed in real time and is available while the well is being drilled.

An early example of basin modeling in a real time look ahead mode is shown to demonstrate the challenges that have been addressed to date. Through careful examination of a case where performance could have been better, the authors reveal the weaknesses of the approach such that they can be better understood.Furthermore, the example demonstrates the capability to update the prediction of pore pressure ahead of the bit and use this advance prediction for other solutions such as wellbore stability computations. Aggregated look ahead performance results from five other projects are revealed that demonstrate the ability of this technology to provide information to operators that can improve the safety and performance of well construction.
Health Management at Workplace
Authors: Lim M.
Published: December 2007

Background

The effort to implement a workplace health programme began two years ago, when the company was reviewing the staff fitness level and safety. It was found that age has a bearing on physical health.

The age profile indicator affirms a need to implement measures to promote a healthy lifestyle as most of the oil spill specialists are in their 40s and have been with the company since inception.

In addition, great emphasis is being placed on the company preparedness as a Tier 3 oil spill response centre. The company is on standby 24 hours a day, 365 days a year.

Staff fitness and safety are paramount. Thus there is a need to build up staff fitness stamina by implementing wellness programme to promote healthy lifestyle.
Behavior Based Safety—Implementation, Learnings and Results of Loss Prevention System in ExxonMobil Malaysia
Authors: Kathirgamanathan T. , Wong T. K.
Published: December 2007

The safety performance of ExxonMobil's Malaysian operations is among the best in the company worldwide. One of the key contributing factors for the success is the adoption of a Behavior Based Safety (BBS) management system to achieve a breakthrough in safety performance, which had plateaued in the mid-1990s. A BBS process known as the Loss Prevention System (LPS) was implemented in 1999. Since then, steady improvements have been achieved.

ExxonMobil Malaysia's (EMM's) application of BBS has been successful due to the use of effective, proactive tools, and a focused commitment from all levels of the organization. Using the LPS model, the EMM BBS implementation included the use of the following tools: A personal work behavior self-assessment,A behavior observation of work performed by colleagues,Job safety analyses,Incident and near miss investigations, andRoot cause analysis of incidents, near misses, and deviations from standards.

The process emphasizes proactive interactions, positive reinforcement, and constructive improvement suggestions to encourage safe behavior. A key ingredient of the process is the job expertise of the workers themselves and their colleagues, regardless of whether they are employees or contractors. The effort also defined roles and responsibilities for all levels of the EMM organization, from the field operators to senior management. Active involvement at all levels has been a significant factor in the success of the BBS process in EMM.

This paper describes the BBS tools, action steps, learnings, and results of that experience in the EMM operation.
Biodiversity Management in Oil and Gas Sector—Indian Scenario
Authors: Gomathi M.
Published: December 2007

Biodiversity management is a fast emerging challenging issue shaping the future of global exploration of oil and gas industry. The objective of the paper is to envision this "highly sensitive challenge" as an " appealing sustainable opportunity" and thereby balance the scales of ‘environment’ and ‘development’ in this sector. This paper is based on experiences of a global oil and gas major, Oil and Natural Gas Corporation Limited (ONGC), India in operating in such sensitive areas and an in-depth study of various International case studies, policies and publications.

The paper highlights the increasing need for factoring biodiversity management as a key corporate issue in the risk management of E&P business, gives a broad overview of experiences /constraints/critical issues of operation in such environments, relevant National legal framework and upcoming revisions, ONGC's Corporate HSE policies, best administrative and operational Management practices and attempts to chart a roadmap in dealing with the biodiversity issues faced by the oil and gas sector in the Indian context.

Though various global initiatives have called for "multi stakeholder partnerships", "Impact mitigation strategies" and "Integrated Environment & Social Impact Assessment process", this paper strongly advocates the following two strategies The need for development of tailor made "performance rating" matrix model for Biodiversity Management for oil and gas sector to assess/measure the actual strategies adopted by a company in its attempt to reduce its operational footprints in sensitive environments. In the absence such rating systems, the Government, Industry and Conservation organizations shall continue to grapple over a series of bargains over accessibility, funding and conservation options in these areasFormation of "Merger initiatives" in India as "Sustainable Development Partnerships" under aegis of Ministry with various stakeholders as members

These shall Pave way for a consistent policy in dealing with bio diversity management in this sectorEnsure transparent workable relationships between industry/government/public to achieve sustainable equitable sharing of benefits.
High-Pressure Jet Kerf Drilling Shows Significant Potential to Increase ROP
Authors: Cohen J. H. , Deskins G. , Rogers J.
Published: December 2007

The most effective approach to reduce the cost of drilling oil and gas wells is to increase penetration rates. Researchers have investigated means to drill rock faster for many years, and jet-assisted drilling is one approach that has been considered various times. While incorporating various jetting techniques into the drilling process has been found to be effective in increasing penetration rates, problems with leaks, system reliability, and high costs have prevented widespread application of high-pressure (HP) jetting technology.

An R&D project[1] sponsored by the U.S. Department of Energy was undertaken to develop and field test a HP drilling system based on employing specially designed jet bits to erode radial kerfs (grooves) in the rock which are then broken off by the mechanical cutters. Tools required for jet kerf drilling (JKD) were successfully developed and tested in the laboratory and field.

This project's original concept was to employ coiled tubing (CT) to convey the BHA into the well. Later in the effort, rotary drilling with jointed pipe was also investigated and successfully implemented using an upgraded conventional rig and commercial double-shouldered drill pipe.

Project highlights include development and testing of HP motors and jet kerfing bits, a field test using a CT-based drilling system, and a second field test using conventional rotary drilling equipment. Based on these successes, JKD is now highlighted as a technology that has potential to increase penetration rates while remaining reliable and economic.

Implementation of JKD tools and techniques within the USA gas and oil industry is now feasible. However, it will not be a simple process, with the current business environment remaining the most challenging hurdle. Successful implementation will require close cooperation from drilling contractors, operators, and bit manufacturers.
Macrobentihic Community as Environmental Pollution Indicator
Authors: Kulleh J. A. , Kip S. H. , Seng L. T.
Published: December 2007

Shell Malaysia is an exploration, and production (EP) oil and gas company in Malaysia, a contractor to the national oil company, Petroliam Nasional Malaysia (PETRONAS), operating in Malaysia since 1910. Initially, explorations and production of oil and gas were land-based, but are now entirely in the marine environment, since the late sixties.

In 1981, the first of a series of quantitative environmental assessment studies was carried out on the nearshore marine environment at the crude oil terminals at Bintulu, Lutong and Labuan, as well as offshore oilfield platforms – Temana A, Temana B, West Lutong a, B & C.

It was not the company's intention right from the beginning to assess every living resource in area of its operations, but through carefully selected parameters that were relevant and effects that are measurable as indicator for environmental stress. The resource selected for quantitative study was the macrobenthic communities, which are important indicators of water quality. The individual is referred to as macrobenthos. These macrobenthos are relative long-lived and do not move far away once they have settled in a particular area.

In the first environmental assessment study in 1981, an impact-reference sampling design was adapted because of the absence of historical baseline data for the macrobenthic community. Reference sites were chosen to be as similar as possible, in term of exposure and geomorphology, to impacted sites. In subsequent assessment studies, reference sites may not be necessary.

Three environmental assessment studies are used to illustrate the use of macrobenthos as pollution indicators in Shell Malaysia EP operational areas. The first case is the use of oil-based mud at Erb West oil field at water depth of 60m. Pre-drill and post-drill environmental assessments were performed. The macrobenthic community was drastically reduced within the 100m from drilling center. This reduction correlated with the elevated level of hydrocarbons.

The second case was the effects of effluent discharge from Labuan crude oil terminal, one of the first sites chosen by Shell Malaysia EP for environmental assessment in 1981. This site was again studied in 1993 and 2004. The changes observed in the structure of the macrobenthic community in these 3 studies showed a pattern similar to that of organisms responding to organic enrichment. The analysis of the macrobenthos data indicated the site studied there has improved from a polluted environment in 1981 and 1993, to one of a much cleaner environment in 2004.

The third case was the recovery of intertidal macrobenthos from crude oil spilled from Bintulu crude oil terminal in 1996. The analysis of the macrobenthos data indicated the recovery of the macrobenthos within three months in exposed intertidal zone, but more than a year in enclosed bay.

It is very important that raw data of any environmental studies be included in the reports, which are accessible for review.
Seismic Facies Identification and Classification Using Simple Statistics
Authors: John A. , Lake L. W. , Torres-Verdin C. , Srinivasan S.
Published: December 2007

The identification and mapping of rock facies is important to reliable reservoir characterization. Traditionally, facies identification and mapping is based on inspection of core data and/or well-log signatures, a procedure that has subjective aspects as it is relies on samples from only a very small portion of the reservoir. Such identification is also difficult to perform at the onset of the exploration stage due to lack of sufficient well data. This paper demonstrates a simple, practical approach to identify and classifiy facies from seismic amplitude data using basic statistical concepts.

Within a geologic facies, measured properties (in this case acoustic impedance or AI) are assumed to differ mainly as a result of random additive events and are modeled by a normal distribution, as justified by the central limit theorem. The facies are identified by estimating the combination of facies volume fractions and distribution parameters (means and standard deviations of the facies probability density function), that best fit the population distribution of AI. A simple form of Bayes theorem is then used to compute the probability of occurrence of each of the facies at the measured locations. This generates a volume of facies probabilities corresponding to the seismic volume. Such a volume can be used to perform facies-specific petrophysical analysis or be a starting point to generate multiple realizations of petrophysical properties. The approach is easy and transparent to use with no significant computational requirements even on large data sets.

We describe an application of the procedure to a synthetic reference data set and a Gulf of Mexico AI data set. Mapped probabilities of the individual facies show the spatial continuity and geologic character of the underlying depositional environment. Property values within the mapped regions are substantially less variable than the original data over the entire region. The within-facies semivariograms exhibit much less spatial correlation than across all facies. Since the facies are mapped over an exhaustive data volume, this approach considerably reduces the need for the geostatistical construction of property distributions within them as long as a high correlation exists between the seismic attribute and petrophysical properties.
Frequency Dispersion Effects on LWD Propagation Resistivity Measurements
Authors: Haugland S. M.
Published: December 2007

Measurements sensitive to the resistivity of earth formations acquired during and after the drilling of oil and gas wells can be subject to frequency dispersion effects. The frequency range of interest in this paper is from practically zero to two million cycles per second. The most common measurements are wireline induction (10 – 100 kHz) and LWD propagation resistivity (0.4 MHz – 2 MHz).

Methods suggested in the literature to analyze data subject to this effect range from simply assuming Rt is the deep 2 MHz attenuation resistivity to applying a CRIM (complex refractive index method) or other mixing law such as the Hanai-Bruggeman model. No physical basis was given by the authors who recommend using the 2 MHz attenuation resistivity. In addition, the attenuation resistivity depends on a dielectric assumption which varies between service companies as does the spacing for the deep measurement. On the other hand, the mixing models appear to be impractical because they depend on material properties such as the formation fluid content, pore microstructure, clay content, grain size, porosity, tortuosity, etc.

Published log examples consistently indicate that dispersion effects occur in formations with anomalously large apparent dielectric constants. By definition, a medium with a large apparent dielectric constant is readily electrically polarized. This paper applies the accepted knowledge that polarization effects over the frequency range of interest tend to be dominated by interfacial relaxation within the rock-pore system. On this basis, an equivalent electric circuit model is used to determine the low frequency limit for the conductivity and dielectric constant based on LWD propagation measurements.

Log examples will be presented where the algorithm is applied to data from a dual frequency LWD propagation resistivity tool with three fully compensated spacings. As expected, the low frequency limit conductivity from data at each spacing is shown to be higher than the dielectric-independent resistivity values used to compute the parameters of the circuit model. The low frequency limit dielectric constant is also higher than the apparent dielectric constants used in computing circuit parameters.

The algorithm and its underlying theory are discussed in detail. The possibility of applying it to anisotropic and inhomogeneous cases is also discussed.
Behavior-Based Safety Implementation in Thailand: Factors Critical to Success
Authors: Whitney P. , Stanley A.
Published: December 2007

A systems-oriented, behavior-based safety (BBS) process was initiated during 2004 in Songkhla, Thailand. Songkhla was selected as an implementation site because of their willingness to be involved, good safety performance, and high expectations for success. Being a systems oriented approach, the process included elements for team development, behavior observation and feedback, data recording and analysis, improvement action planning, and sustainability.

Factors critical to the successful implementation were: management leadership, communication, and employee ownership and participation. Examples are given showing how these different factors were applied effectively, including: how management showed leadership, the types and frequencies of communications, how the employee team was organized, and how employees were motivated to participate. To monitor progress, it was important to link these factors to meaningful performance measures.

Historical performance was measured primarily on injury rates. While useful, lagging indicators emphasize the negative aspect of performance, and when rates are low, it is difficult to differentiate true improvement from statistical noise. For BBS, several leading indicator performance measures were introduced. Performance indicators other than injury rate were needed for two reasons: (1) injury rates before the BBS process began were low, and (2) the BBS process was designed to be proactive. Plotting process performance measures over time indicates improvement but there are limitations to the measures.

Based on employee and management feedback, and performance indicators, the program has been successful. Halliburton implemented over 20 BBS processes in several different countries before the Thailand implementation. The critical success factors are broadly applicable although effective application varies with culture and local environment.
Uncertainty and Value in Integrated Asset Modelling
Authors: Crerar A. , Robertson A.
Published: December 2007

The paper will illustrate the application of asset-scale modelling and the benefits thereof, including an analysis of the effect of quantifiable risk on development strategy selection.

While integration asset modelling (IAM) is not of itself a novel topic, practical applications of the technique applied from sub-surface calculations through to commercial/financial analysis are nevertheless uncommon and those including a rigorous treatment of uncertainty still rarer. Included in the paper will be a brief analysis of both the benefits of IAM and suggestions on why it is perhaps not more widely applied.

The main body of the paper, however, will cover two case studies - descriptions of projects carried out using the RAVE (Risk And Value Engineering) IAM software. The first case study will be based upon the Brae asset, operated by Marathon Oil UK. The Brae asset is complex, both technically and commercially, and represents a huge infrastructural investment in the CNS. The paper will illustrate the means by which IAM was used to "see through" this complexity to assist in the forward strategic planning of the asset.

The second case study will describe the development of a reserve as a third party tie back to an existing host platform. Use of the approach in this case allowed rapid, value-based analysis of competing development alternatives (such as host selection, artificial lift techniques and well count) including the sub-surface uncertainty inherent in pre-FEED development studies.

From the case studies presented here and numerous similar projects, the authors will present the conclusions that risk- inclusive integrated asset modelling is both feasible and valuable in marginal and mature environments.
Real-Time Information to the Engineer’s Desktop - How Murphy E&P Improved Production Management
Authors: Oberwinker C. , Holland J. , Mayfield D. , Dixon D.
Published: December 2007

Real Time is the new buzz in the upstream petroleum industry. So far, operators have been the main users of data measured at second or minute time increments to manage wells and keep them on production. Engineers usually see only a sub-set of the data - the daily production volumes and rates along with a few select- gauge pressure and temperature readings. The limited data means that they only see the result - the production volumes - and not the reason for a certain production parameter - e.g. choke size, pressures, temperatures.

SCADA - Supervisory Control And Data Acquisition - is the system, which connects to the gauges, collects the measured data and stores it in a database. Operators on the platform have direct access to this data and use them to control the wells. If the engineers see this data at all, they usually get them through a web browser interface and in a format they cannot directly use for their analysis. One of the reasons for this is that many SCADA providers come from other industries where the needs are quite different and the network resources are much more substantial.

This paper will introduce a new concept of integrating high frequency data up to the management level. Each level of the organization sees as much as they need or want to see of the high frequency data. The engineers have exactly the same view as the operators at the platform - at the same time. This might seem to be a problem at the first, but in the long term, it is an empowerment of the operators and brings engineers and operators closer together working as a team to manage the wells. The data also allows management to monitor the oil- and gas production leaving the platform to see if the target volumes are reached, or if a well is shut in.

Murphy has implemented this system in all of their operated deepwater assets in the Gulf of Mexico. This paper will give insights on how drastically it transformed the way of doing their daily work, how it changed the way operators work together with engineers, and in addition, an outlook of further improvements to the system based on their experience so far.

Note: All values in the figures at the end of the SPE paper are randomly generated and do not represent reality.
Realizing Single-Diameter Wellbore Technology
Authors: Waddell K.
Published: December 2007

The provenance of the single-diameter well consists of over 350 commercial installations of solid expandable tubular systems and a concise, yet encompassing development plan. The maturation of expandable technology has led to successful design, construction and testing of individual components and the subsequent subsystem that will ultimately help realize the single-diameter well.

This evolutionary step brings the energy industry that much closer to a fundamental change in wellbore construction. The single-diameter well represents a paradigm shift in the way wells are drilled and results in significant benefits that include conserving resources, saving time, and creating a smaller environmental footprint. All of these features result in considerable savings that reflect the practicality of this value-added technology.

This paper will explain the overall scope, approach and implementation essential to realizing the single-diameter well. In addition, this paper will explain how the technical development of necessary tools for the single-diameter well brings significant savings to drilling operations. Using business cases, this paper will detail where the value of application is realized. In conclusion, this paper will outline future possibilities for the technology and how it will impact the industry.