bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying Modern 3D Modeling Technology for a Large Gas-Condensate Field in the Pricaspian Basin
Authors: Dmitrievsky S. A. , Bolotnik D. N. , Posvansky D. V. , Sarkisov G. G. , Schepkina N. E. , Yufin P. A. , Zaitcev I. U.
Published: December 2007

This paper will discuss modeling and compositional simulation of a large gas-condensate field in the Russian part of the Precaspian basin.

The naturally fractured limestone reservoir is highly heterogeneous with complex geology and having high initial pressure. The field was modeled using different reservoir modeling software packages : STORM, TIGRESS and ECLIPSE

The behavior or reservoir was modeled with 3D simulation grid, having corner point geometry. TIGRESS and ECLIPSE compositional models with dual porosity options where used

A lack of geological and laboratory data was complicating the modeling task. Reservoir geometry was obtained only from well observations, using mapping algorithms, implemented in TIGRESS software Dual porosity sigma values was obtained from well test data, using ECLIPSE WELLTEST and TIGRESS pressure analysis software and were history matched. Only total porosity values from petrophysics observations were available in this project At first the total porosity distribution was obtained at fine 3D grid, using STORM stochastic modeling technique and upscaling procedures.

Fractured matrix porosity was calculated from total porosity, using simple constant multipliers, which were then treated as history matching parameters. Permeability distribution was obtained from a little amount of core data and porosity – permeability correlation, using STORM petrophysic properties modeling facilities. Then permeability data was corrected, to be consistent with well tests interpretation results.

Three phase study was initialized, using equilibration algorithms, implemented by TIGRESS and ECLIPSE software

The flow dependent skin factor options for calculation well inflow performance was used to take in account non – Darcy flow to the wells, having high pressure dropdown.

3D visualization tools implemented in RESVIEW, TIGRESS, ECLIPSE software allowed us to view and better analyze our input data and results.

Modem 3D modeling technologies allowed us to achieve a better description of the large and complicated reservoir, giving more reliable predictions of the field production performance
Applied Uncertainty Analysis Using Stochastic Modelling
Authors: Sandsdalen C. , Barbieri M. , Tyler K. , Aasen J.O.
Published: December 2007

At the appraisal phase of an offshore field development, there are limited amount of hard data for reservoir description. For that reason significant uncertainty exists not only in the variability of the observed petrophysics and facies data (heterogeneity uncertainty) but also in the representativeness of the observed data (model parameter uncertainty).

The aim of this study is to quantify the effect of these uncertainties on the dynamic behaviour of the reservoir and provide input for the overall uncertainty analysis. These uncertainties are important at this field development stage, contributing to decisions being made with respect to gas contracts, facility design and commercial evaluation.

It is difficult to incorporate the model parameter uncertainty by simply generating a certain number of realisations out of one global set of model parameters - i.e. a standard stochastic modelling approach. Thus, different parameter distributions were utilised as input to different heterogeneity models provided by the disciplines involved (sedimentology, petrology, petrophysics and geology). In order to ensure equi-probability of the realisations generated, a higher hierarchical model with two individual levels of uncertainty was used.

The problem arising with a hierarchical model is the large number of possible model parameter combinations. Hence, the Latin Hypercube technique was used for experimental design when planning for realisations. 99 realisations of the reservoir plumbing have been generated including facies and petrophysics modelling. However, because of the complexity of the fluid system and the need for compositional reservoir simulation very few of the realisations could be evaluated with the full field simulation model. The realisations were therefore ranked on element models using front-tracking and simplified black oil models.

The results of this analysis were applied in the overall uncertainty analysis. In addition, the results contributed significantly to the understanding of the reservoir and its potential dynamic behaviour.

Introduction

Reservoir simulation is an indispensable tool in modern reservoir management. However, large uncertainties are known to exist in the production profiles thus calculated. One reason is that heterogeneities are generally poorly represented, due to lack of knowledge of the spatial distribution of the architectural elements in the reservoir. Specially in offshore reservoirs, the large distances between wells result in geological models which rarely represent the heterogeneities influencing the fluid flow. In recent years, a large effort has been dedicated to representing more correctly the geological features of the reservoir and the associated uncertainty. However, to date, little has been done in the modelling to correctly handle uncertainty of the input parameters which is critical to the outcomes of the geological architecture.
A Production Logging Measurement of Distributed Local Phase Holdup
Authors: Halford F. R. , MacKay S. , Barnett S. , Petler J. S.
Published: December 2007

This paper describes early UKCS experience of a new production logging sensor, the Digital Entry and Fluid Imager, or DEFT* tool.

Deviated and horizontal wells can cause complex flow regimes to arise that render interpretation of conventional production logging sensors difficult or sometimes impossible.

The DEFT tool is a new type of production logging tool which facilitates the understanding of the nature of wellbore flow and improves confidence in interpretation. The tool makes four independant measurements of the phase holdup, distributed in differring quadrants of the pipe cross section.

Results to date show that the DEFT tool gives a direct count of the dispersed phase bubbles. Each probe can give an indication of the flow type, the absolute velocity of the dispersed phase, and the bubble flow direction. As the four measurements are distributed at different locations within the pipe cross section, an image of pipe flow may be interpreted.

Early results also show how the DEFT tool can be used to define the location of oil entries and to pin-point circulatory flow.

The paper briefly describes the tool principles. Interpretation is illustrated with example logs made during its field introduction.
Underground Disposal of Acid Gas in Alberta, Canada: Regulatory Concerns and Case Histories
Authors: Longworth H. L. , Dunn G. C. , Semchuck M.
Published: December 2007

Over the past couple of years oil and gas operators in Alberta have been faced with an increasing challenge to reduce atmospheric emissions. One of these emission sources comes from oil and gas pools that contain uneconomic quantities of hydrogen sulphide and carbon dioxide (acid gas). Disposal of this acid gas to underground formations is sometimes a cost effective alternative to sulphur recovery and it also can reduce the public concern resulting from sour gas production and flaring

In Alberta, the Oil and Gas Conservation Act requires that operators apply for and obtain approval from the Alberta Energy and Utilities Board (EUB) to dispose of the acid gas. Before approving any scheme, the EUB reviews the application in order to satisfy several primary issues: maximizing conservation of hydrocarbon resources, minimizing environmental impact, promoting public safety, and ensuring that the equity interests of mineral rights owners are protected. To adequately address these matters, the EUB requires that applicants submit information regarding surface facilities, disposal well configurations, and reservoir factors. This paper discusses the information required and describes the process that should be followed by operators who wish to obtain EUB approval for underground disposal of acid gas In addition, this paper discusses the performance of some of the acid gas disposal schemes currently operating in Alberta.
MB Solution for High Pressure Gas Reservoirs
Authors: Elsharkawy Adel M.
Published: December 2007

Accurate estimation of the initial gas in-place for high-pressure gas reservoirs is quite often difficult because of the effect of formation compressibility and the uncertain presence of water influx from small, associated aquifer or adjacent shales.

This paper presents a material balance solution for estimating the initial gas in-place and predicting the prevailing production mechanism for high-pressure gas reservoirs. The material balance solution incorporates water influx from aquifer, water influx from shale, formation expansion, connate water expansion, and formation of condensate. Application of the proposed solution to four case histories of high-pressure gas reservoirs shows that this solution would successfully estimate the IGIP after production of 15% of the initial gas in-place and predict the prevailing reservoir production mechanism. In comparison with the available methods, the proposed solution requires no prior assumptions about the formation compressibility, aquifer size, or volume of adjacent shales.
Multi Model Simulation Study for Strongly Faulted Gas Condensate Reservoir Using Fault Block Modelling
Authors: Ursin Jann-Rune , Mæland Leidulf
Published: December 2007

Optimization of reservoir performance is strongly related to feasible evaluation of reservoir uncertainty. In modern reservoir engineering, a substantial amount of effort is allocated to maintenance and upgrading of what is believed to be the current best realization model of the reservoir, where reservoir uncertainty is demonstrated through parameter variation. This technique is frequently applied even though the nature and extent of uncertainty associated to reservoir characterization, strongly suggests a multiple model approach, i.e. visualization of reservoir uncertainty through realization of alternative models. Awareness of this problem is particular important in the case of strongly faulted gas- and condensate reservoirs.

The model described in this paper is designed for production from gas or gas condensate fields, where modelling of highly faulted and compartmentalized reservoirs is severely impeded by the nature and extent of known and undetected faults and, in particular, their effectiveness as flow barriers. The model redefines individual fault block traps in terms of block volume and cross-flow probability to adjacent blocks, where geological uncertainties are carried through in the model by error propagation techniques. Three different realizations of reservoir models are created; one representing the most likely (average) reservoir while two others represent the extreme alternatives, reflecting the reservoir uncertainties. The fault block evaluation is treated as input to material balance calculation, where reservoir production is assumed to take place from individual block volumes.

The reservoir model is easy to modify by varying block volumes and/or cross-flow probabilities, according to improved knowledge about the reservoir or simply as a sensitivity test of the degree of communication across fault barriers. The model also estimates the total well drainage coverage and the sequence of blocks from where wells should start production. The model may also certify the research area of interest, where improved information about the reservoir has the greatest impact on improved reservoir performance.
Sorption Irreversibilities and Mixture Compositional Behavior During Enhanced Coal Bed Methane Recovery Processes
Authors: Chaback Joseph J. , Morgan Don , Yee Dan
Published: December 2007

Enhanced coalbed methane (ECBM) recovery processes rely on the sorption of a stripping or displacing gas to recover the sorbed methane. Both the adsorption and desorption of methane and the injected gases are important to the success of the process. Oxygen, which can chemisorb to coal, is expected to show different adsorption than desorption behavior. However, adsorption and desorption isotherms for mixtures of physisorbed gases such as nitrogen and methane appear similar in form to those for oxygen. Moreover, results from a field ECBM recovery project also suggest that in the mixed state physisorbed gases may show different behavior during desorption than during adsorption. Because reservoir simulators typically use a reversible equilibrium sorption model such as the Langmuir isotherm, the presence of hysteresis due to sorption irreversibilities could affect the reliability of the simulations.

Constant composition expansion and constant volume depletion sorption results were analyzed. This analysis demonstrates that although mixtures of physisorbed ECBM recovery gases (no oxygen) become enriched in the more strongly held component during desorption, the process is one of reversible equilibrium sorption and isotherm models such as the extended Langmuir isotherm effectively capture this adsorption/desorption equilibrium. No additional changes to the simulator are needed because of this compositional effect. However, for oxygen-bearing gases modification of the Langmuir isotherm will be needed to quantitatively represent adsorption/desorption behavior during an ECBM recovery process.
Case History of a Unique Gas Injection Scheme and its Simulation Using Material Balance Based Simulator
Authors: Behbahani H. S. -Z. , Kharrat R. , Vossoughi S.
Published: December 2007

A gas injection for the purpose of pressure maintenance was initiated in a field located in south of Iran in 1984. It is the largest gas injection project in Iran and possibly in the world without the use of compressors. The field was discovered in 1968. It consists of two non-communicating formations one on top of the other namely Asmari and Bangastan group. The Asmari reservoir contains oil and the Bangastan reservoir contains dry gas with little amount of condensate at much higher pressure. Gas is produced from one well completed in Bangastan reservoir and injected into an injection well completed in Asmari reservoir by a direct pipeline.

History matching was performed over 18 years of production of the Asmari field. Long term prediction of the reservoir performance was obtained for 42 years above the initial 18 years of history matching. Prediction was evaluated under different scenarios namely: 1) natural depletion, 2) pressure maintenance, and 3) repressurizing the reservoir close to its initial pressure.

This paper will present the actual reservoir data for both formations over eighteen years of their operation. In addition, history matching and future performance of the reservoir predicted by a simple simulator based on material balance concept will be presented. It is encouraging to observe a satisfactory match of the reservoir performance and to gam insight into its future performance without resorting to a much more sophisticated and much more expensive simulators.
Application of PermLog - A New Log-Based Permeability Estimation Method
Authors: Semmelbeck M. E. , Diyashev I. R.
Published: December 2007

This paper presents error analysis and applications of a new method for estimating permeability from logs. This method is called PermLog and its development is documented by Semmelbeck et at1. We present an example application of PermLog and show how it can be used with pressure transient testing to characterize complex, low to moderate permeability gas reservoirs. We also present the results of a detailed error analysis in which we determine the expected accuracy of the PermLog permeability estimates. We show confidence intervals expected from PermLog based on assumed accuracy of parameters used in the PermLog analysis.

Well tests in complex multilayered reservoirs can be analyzed with more realistic reservoir models when layer permeability estimates are provided by the PermLog analysis. Monte-Carlo error analysis indicates that at least 80% of permeability estimates from PermLog will be within a factor of 3 of the true in-situ gas permeability when the permeability is in the range of 0.01 to 10 md.

The permeability estimates fine-tuned by matching pressure transient behavior will lead to better performance forecasts and optimization of stimulation treatments and well spacing.
Discriminant Analysis as a Technique for Exploitation of Petroleum Reservoirs
Authors: Schrider Leo A. , Byrd Jack
Published: December 2007

Discriminant analysis, a statistical technique, was used to classify oil wells into productivity groups based upon data obtained productivity groups based upon data obtained from geophysical well logs. A calibration run conducted in the northern area of the East Canton oilfield verified that valid forecasts can be obtained by the procedure. Of 20 wells studied, four appeared to have a greater potential than that indicated by actual potential than that indicated by actual production figures. A similar study of the production figures. A similar study of the southern area of the East Canton reservoir also proved discriminant analysis to be effective for predicting productivity, although different variables were significant than those for the north reservoir. Discriminant analysis was indicated to be adequate and potentially helpful in arriving at decisions potentially helpful in arriving at decisions concerning well completion.

Introduction

Located in northeastern Ohio, the East Canton oilfield is one of the largest ever discovered in the Appalachian basin. The field now comprises over 60,000 acres with more than 1,000 oil wells. Fig. 1 shows the field and illustrates a proposed additional drilling area—one of more than 500 similar locations for new wells in the area. Upwards of 12,000,000 barrels of premium Pennsylvania Grade crude oil have been obtained from the field; current production is about 11,000 barrels per day.

Exploiting the East Canton reservoir presents many problems to the petroleum presents many problems to the petroleum engineer, not the least of which is deciding to complete a well. Log data and field experience in offsetting wells can be helpful but evaluating oil wells for porosity and hydrocarbon saturation on the basis of log analysis is especially difficult. Few of the wells have been plugged as "noncommercial" immediately following drilling, but about 20 percent of them could have been plugged percent of them could have been plugged because they will not return drilling and completion costs.

Discriminant analysis, which has been shown to be useful in oil and gas exploration and other areas of endeavor, was investigated by the Bureau of Mines as a method of predicting oil well production from the East predicting oil well production from the East Canton field. Current oil well production data and log data serve as input to the discriminant function, and the model is then used to classify new wells into high, medium, and low production as a function of log-determined reservoir properties. Rate of return from a new well can then be estimated, and a decision can be made concerning completion of the well. A unique feature of the concept is that the statistical prediction technique adapts itself to the reservoir.
First Assessment of Effects of Air-Gun Seismic Shooting on Marine Resources in the Central Adriatic Sea
Authors: La Bella G. , Cannata S. , Froglia C. , Modica A. , Ratti S. , Rivas G.
Published: December 2007

A series of investigations were carried out to test the effects of air-gun seismic shooting on main fishery resources of the Adriatic Sea during summer 1995.

The energy source used for the trial was formed by one air-gun array made up by two sub-arrays consisting in 8 air-guns each developing a total volume of c.a. 2500 i3 at 2000 psi with an amplitude of 60 bar/m. The interval between two was of 25 s The intensity was of 210 dB re 1 mPa-m/Hz.

Acoustical and spectral analysis were performed simultaneously in the surveyed areas to correlate fishery and behavior observ ations with sound pattern of the energization.

Main results were: Analysis of trawl catch data evidenced no significant changes before and after the air-gun seismic profiling.Echosurvey relative estimate of pelagic biomass, performed simultaneously to trawling operations, failed to evidence any significant change in the pelagic biomas.Small differences were observed in the trammel net catch composition, but one single set of pre-post fishing operations could be done in the study period.Similar density estimate were obtained from dredge surveys performed by an hydraulic dredger before and after air-gun seismic profiling over a clam bed in 14 md.Video recording of captive fish, kept into cages moored on the sea bottom at 12 m depth, evidenced a behavioral response to the approach of the sound source; but no lethal event was recorded on captive sea-bass immediately after the seismic shooting.Biochemical and histological analysis were performed to verify if it is to be related to the captive condition or is somewhat consequent to the air-gun energization.

These results confirm that no relevant effects are induced on fishery resources by seismic air-gun shooting.
Duri Indonesia Air Emission Inventory and Dispersion Modeling Study
Authors: Soetjiptono T. E. , Nugraha S. , VanDerZanden D. F. , Petersen L. P. , Verstuyft A. W. , Schievelbein V. H. , Rabideau C. G. , Gilmer L. K. , Comey K. R.
Published: December 2007

The Caltex Pacific Indonesia production field located in Duri, Indonesia, is the world's largest steam flood. Because of the large scale of these operations, there is an interest in understanding the emissions into the atmosphere from the various sources in the field as well as the possible impact on the air quality resulting from these emissions. To be proactive and to fulfill this need, a study was done to inventory emissions from the facilities in the field and to use air dispersion models to estimate impacts on the air quality using the inventory results. This paper will discuss methods and procedures used in the study to quantify the emissions from the following sources in the Duri field: process vents, production impoundments and wastewater canals, Toads, fugitive emissions, storage tanks, and combustion sources. Emissions of the following compounds were addressed in the study: nonmethane hydrocarbons (NMHC) and aromatic hydrocarbons (BTEX), hydrogen sulfide, nitrogen oxides, sulfur oxides, paniculate matter (PM), and carbon monoxide. Because of the diverse nature of the sources in the field, a wide range of emission estimating procedures were used including direct measurement methods, empirical methods based on mass transfer principles, and standard emission factors or procedures available from the United States Environmental Protection Agency (U.S. EPA). To quantify and track the emissions data generated, a computerized emissions inventory was developed. This paper will also discuss the dispersion modeling methods that were used to estimate the ground level concentrations in the surrounding areas using the data developed in the emission inventory. These discussions are based upon the results of a preliminary study which is limited to a portion of the Duri production field.
Environmental Health and Safety Management - A World Class Perspective
Authors: Seabrook Kathy A.
Published: December 2007

A global environmental health and safety (EH&S) management system is designed to identify risk, provide risk control resources and create a work environment where team work and continuous improvement are rewarded. Through this process, corporate health and safety goals as well as corporate values and results are achieved. This paper outlines a proactive approach to global environmental safety and health management, where corporate leadership empowers local non-US business units and the EH&S management system is integral to the business process and aligned with the corporate strategic plan.
A Reassessment of the Gas Supply and Demand Situation
Authors: Linden Henry R.
Published: December 2007

Primary energy requirements forecasts are reconciled with an independent forecast of natural gas demand to arrive at a firm basis for assessing supply deficiencies. Gross additions to proved reserves in the lower 48 states are projected by means of the updated IGT model of natural gas discovery and production, and by a simpler technique. These projections give an average range of gross additions of 15 to 20 Tcf through 1980 and show a decrease to an average level of about 15 Tcf in 1990 and 10 Tcf in 2000. This compares to a current need of about 35 Tcf of lower 48 reserve additions. It is clearly shown that it is a lower 48 states resource base of, at best, 1,000 Tcf, compounded by insufficient economic incentives to fully develop even this limited resource base, which is responsible for this gas supply problem. Thus, after allowing for reasonably optimistic projections of imports of pipeline gas from projections of imports of pipeline gas from Canada and Mexico, and liquefied natural gas from Africa and South America, and for pipeline transport of Alaskan gas, natural gas supply defficiencies in the lower 48 states still increase by about 1 to 1.5 Tcf each year beginning in 1972 to 1973. This assumes a minimum average reserves to production ratio of 10 years. Since no competitive or technological factors are apparent which would reduce gas demand, these supply deficiencies, which would reach about 10 Tcf in 1980, 20 Tcf in 1990 and 35 Tcf in 2000, will either be filled by less attractive energy sources or, partially, by synthetic pipeline gas from coal. Assuming development of pipeline gas from coal. Assuming development of commercial processes from existing technology at the fastest practical rate, synthetic pipeline gas from coal production, beginning in 1980 and reaching 5 Tcf/year in 1990, appears feasible at costs competitive with any other known sources of supplemental pipe-line-quality gas.

Introduction

In 1970, on the basis of preliminary statistics, net production of natural gas in the lower 48 states was about 22 Tcf, an increase of roughly 6 percent over 1969, and total demand for natural gas from all sources also increased to nearly 22 Tcf, or more than 7 percent. Thus, in 1970, as an absolute minimum, gross additions to proved reserves in the lower 48 states should have been 34 Tcf: 22 Tcf to replace net 1970 production plus 12 Tcf to support the 1.2 Tcf increase over 1969 with a 10-year reserve life. Instead, drilling activity continued to decline and actual lower 48 additions in 1970 were only 11.1 Tcf, following equally disappointing lower 48 additions of 12.0 and 8.3 Tcf in 1968 and 1969, respectively. Thus the decline from the 1953 to 1967 average of 19 Tcf/year appears to be, by far, more persistent than earlier temporary setbacks and has resulted in a drop in the lower 48 proved reserves to production ratio of less than 12 years. production ratio of less than 12 years.
Total Quality Environmental Management: Integrating Environmental and Quality Management Systems
Authors: Carley Judith A. , Kubala Gregory , Hudson Tommy , Gibbons Mike , Lawson V. Mark
Published: December 2007

As the oilfield industry strives to globally sustain continuous improvement of environmental and quality performance, companies have come to realize Total Quality Environmental Management (TQEM) is essential in product research, development, manufacturing and services. As our industry endeavors to continuously improve, more emphasis is being placed upon the management systems we apply such as ISO 14000 and ISO 9000. These standards are tools for improving environmental and quality performance, meeting customer requirements, and increasing profitability.

This paper presents actual examples of the successful integration of environmental and quality management systems into an operational TQEM system. Also presented are pilot- study evaluations of the draft ISO 14000 standards by two certified ISO 9000 facilities. Examples of continuous improvement and cross-functional teams as means to merge environment and quality management into the functions of process control, corrective and preventive action, document control, and waste management are presented.

Results and improvements from facilities involved with TQEM are discussed along with their strategies and progress in consolidating the environmental and quality programs into a single, viable management system. The case histories from various facilities demonstrate the implementation of TQEM and how TQEM promotes a cleaner environment, reduces costs, conserves energy and raw materials, minimizes pollutants and wastes, and reduces redundant paperwork.
Oil Spill Fingerprinting - The Practical Benefits For The Operator
Authors: Sinclair J. W. , Grigson S. J. W.
Published: December 2007

The oil company operates North Sea Oil Production Platforms which have several subsea developments connected by subsea pipelines.

A specialist research institute was contracted by the company to obtain reference crude oil fingerprints for each subsea oil pipeline and store this information in a specially constructed computer database and fingerprint matching system.

Both crews from the platform's stand-by vessels were then trained in the correct procedures for sampling small slicks at sea, with laboratory validation of samples collected during the training exercise. Subsequently, during two incidents of leaking subsea pipelines, oil spill samples were taken by stand-by vessel crews. Analysis of the samples onshore, followed by computer comparison of their fingerprints to those of the reference oils in the database, allowed early identification of the leaking pipeline prior to confirmation by ROV inspection.

Oil spill fingerprinting proved a highly cost effective tool, ensuring optimum use of expensive DSV/ROV mobilisation and use. It also permitted pipelines not implicated in the leak to be rapidly put back into operation.
Laboratory and Field Measurements of Vapors Generated by Organic Materials in Drilling Fluids
Authors: Candler John , Churan Marc , Conn Lee
Published: December 2007

In an era of increasing awareness of worker health issues one of the key concerns in exploration activities is the exposure of wellsite personnel to vapors generated by organic materials in drilling fluids. Areas on the drilling location with the highest exposure potentials are the shale shakers and mud pits. These areas are often enclosed in rooms and ventilated to prevent unhealthy levels of vapors from accumulating. In continuing efforts to minimize health risks, new products are evaluated to minimize the volatility of organic materials used in drilling fluids.

This study presents a laboratory technique for measuring vapors generated from organic materials in drilling fluids. Using this technique, data will be presented comparing the volume of vapors generated from diesel oils, mineral oils, synthetic fluids and a water-miscible glycol. Field data collected from the shaker and mud pit areas of drilling operations will be used to validate the laboratory study to field conditions. The potential health effects of the collected vapors will be reviewed.
An Overview of Oil and Grease Determination in Produced Water
Authors: Johnson S. J. , Steen A. E. , Reitsema L. A. , Bansal K. M. , Curtice S. , Khatib Z. , Ray J. P.
Published: December 2007

Produced water discharges are monitored under the National Pollutant Discharge Elimination System (NPDES) program, and one of its provisions limits oil and grease concentration in the water. This paper summarizes the results of studies conducted by EPA and API to compare results obtained using different solvents (Freon or n-hexane) in the gravimetric technique for EPA reporting as specified in Method 413.1 (current compliance method, Freon extraction) and Method 1664 (proposed new method, n-hexane extraction) and discusses the impact of the new method. The outline of an ongoing API project on techniques for measuring oil and grease content of produced water for overboard disposal will also be discussed.
Hydrocarbons and Surfactants: Ecotoxicology in a Marine Pelagic Food Chain
Authors: Skadsheim A. , Hoivangli V. , Labes-Carrier C.
Published: December 2007

Accidental spills and production lead to discharges of petroleum hydrocarbons and surface active agents to the sea. The Norwegian government has set guidelines adopted from the OSPAR commission for assessment and studies of the environmental load from these discharges. The free water masses are poorly studied compared to the benthic processes in this context and we question how oil and surfactants might bioaccumulate in a simplified marine pelagic food chain comprised of algae, crustaceans and fish.

When test methods and species recommended for initial water based acute toxicity studies are to be implemented in more comprehensive studies like assessment of bioaccumulation various problems arose. An improvement of the OSPAR method for the production of Water Accommodated Fractions (WAFs) of oil is presented. Emphasis is on control of oil concentration and distribution in water, and on applicability for studies where larger volumes of WAF are required than for the demand in acute toxicity tests. Acute toxicity assessments of one oil, Blended Arabian Light topped at 150°C, and two non-ionic dispersants, hexa-etoxyparanonylphenol and a sophorolipid, were conducted on OSPAR recommended species. The toxicity responses were in line with observations made by others. At a given concentration the oil particle size during WAF preparation might influence subsequent expression of toxic effects. The same applied for the presence of emulsified oil particles in the WAFs where the organisms were exposed. Reasons for selecting other test organisms than those officially recommended for continued studies on bioaccumulation are presented and discussed.
The Value of ADA-Compliant Pre-Placement Functional Evaluations (PFE) of New Hires for Oil Industries
Authors: Bunch Richard W. , Stansbury P. T. , Stansbury Gilbert J.
Published: December 2007

The saying, "Hard work has never killed anyone", was never used by an OSHA inspector.
The Offshore Supervisor's Role in Safety Management: Law Enforcer or Risk Manager
Authors: Fleming Mark T. , Flin Rhona H. , Mearns Kathryn , Gordon Rachael P. E.
Published: December 2007

This paper describes a project (sponsored by the UK oil industry and Offshore Safety Division of the HSE) which is designed to examine the role of the supervisor in safety and to identify best supervisory practice in offshore work site risk management. To date there has been no in-depth investigation of the offshore supervisor's safety and risk management skills. Research in a number of other industries (e.g. construction, transport and mining) has demonstrated the importance of the supervisor in the management of safety. The safety responsibilities of the offshore supervisor in the UKCS have changed due to the recent extension of onshore legislation to offshore installations. This legislative change has caused a shift away from prescriptive safety legislation to a regime based on risk assessment, placing a legal requirement on supervisors to assess and control the risks to which their work group are exposed. The supervisors role in safety management has been examined by carrying out semistructured interviews with offshore supervisors. The Critical Incident Technique (C1T) has been used as the basis for the interviews that have been carried out to date. The CIT involved getting individual supervisors to describe two recent hazardous operations that their work group had performed, one that had gone as planned and one where there were some difficulties. The initial phase of interviews has identified the formal and informal risk assessment techniques currently being used by supervisors. The differences between supervisors who manage safety effectively and those who are less effective will be identified. How the results of the above and future interviews might be used to establish best supervisory risk management practices will be described.
Assessing the Human Factors Causes of Accidents in the Offshore Oil Industry
Authors: Gordon Rachael P.E. , Flin Rhona H. , Mearns Kathryn , Fleming Mark T.
Published: December 2007

In the past, industrial accidents were reported mainly in terms of technological malfunctions and the human element in accident causation tended to be ignored. Since the frequency of technological failures has diminished, the role of human error has become much more obvious. Preliminary investigations into the accident reporting forms used by some UKCS oil companies indicated that the human factor accident coding systems vary from company to company. The question which remains is: Do these systems adequately cover the human factor problems specific to the oil and gas industry? Data from both the oil industry and other industries regarding human factors causes of accidents should enable the development of a more comprehensive human factor coding category for accident reporting systems.

The present paper briefly reviews the international accident research in various industrial settings such as the nuclear, mining, marine and oil industries. A compilation of the human factors causes of accidents from these source - forms the basis for the assessment of accident reporting systems used on oil and gas installations on the UKCS. A review of the current accident coding systems used by 30 offshore oil operating and contracting companies in the UK will be presented. From this review, further examples are given for a comprehensive human factors coding system for use in the oil industry. It is intended that human factors coding categories are used for accident reporting, safety training and for raising awareness of the human factors causes of accidents.
Heavy Metals in Water Base Drilling Muds used in Several Locations of Oil Fields in Indonesia
Authors: Mulyono M. , Desrina R. , Priatna R. , Sudewo B. , Sawolo M.
Published: December 2007

Heavy metals are parameters to be considered among oilier parameters such as pH, salts, hydrocarbons, culling and fluids when water base muds are to be disposed. In most cases reducing or eliminating heavy metals, either as additives or contaminants, wilt reduce the problems associated witli disposal. Even if all heavy metals are elcminaled from the additives placed in a mud system, however, these contaminants can still become incorporated into the mud from the formation that is bccing drilled.

In Indonesia, drilling muds arc classified as hazardous material according to the Governmental Regulation PP 19/1994. This paper try lo investigate the concentration of some of heavy metals in drilling muds used in several locations of oil fields in Indonesia using Toxicity Characteristic Leaching Procedure (TCLP) extracted with several acids and other extracting agents. "Total heavy metals" content as released through refluxing in strong acids are also determined to correlate between Total Heavy Metals and Extractable Heavy Metals, in order to examine the type of compounds which could be considered as potential pollutants.
Modeling and Implementation of a Database for Multiphase Flow Experiments
Authors: Borthne Gunnar , Johannessen Oddmund , Hedne Paal
Published: December 2007

This paper describes the modeling, development, and implementation of a database for multiphase flow data from a large-scale research laboratory.

The outdoor laboratory facilities include a total of 1000 m pipe connected to fluid processing utilities, liquid pumps, and a 700 kW gas compressor operating at system pressures up to 90 bar. Normally, approximately 100 physical and virtual instruments are used, and at the moment more than 400000 measurements have been logged, processed, and stored in the database. The database communicates with systems for data acquisition and analysis, and researchers can access data from their workstations.

The database is implemented in a relational database management system (RDBMS) with SQL interface. Before the implementation of a database can start, it is important to develop a data model which represents the selected part of the real world in a way that satisfies the system requirements. The different aspects of the data model are treated thoroughly and include (1) experiment, (2) geometry, (3) instruments, (4) measurements, (5) fluids and fluid composition, and (6) project related data.

Entity-Relationship diagrams of the model are presented and explained. Timeseries are stored in the database using a specially developed C function. Other functionality is handled by database triggers and procedures stored in the database itself (written in a procedural extension to SQL), and UNIX shell scripts. Problems and advantages of data redundancy and reuse are discussed, as well as the need to avoid destroying the "history" in the database. The communication with the systems for data acquisition, analysis, and presentation is described.
A Horizontal Well Model Considering Multiphase Flow and The Presence Of Perforations
Authors: Gonzalez-Guevara J. A. , Camacho-Velazquez R.
Published: December 2007

Recently, Landman and Goldthorpe1 presented a single-phase flow model for a horizontal well, coupling the steady-state flow through each perforation with the momentum equations for pipe flow.

In this paper we present a model based on that of Landman and Goldthorpe1, but including the following three improvements. Multiphase steady-state flow is allowed in the reservoir, including the option of considering non-laminar flow toward the perforations. The modifications of the friction factor due to the presence of perforations, suggested by Su and Gudmundsson2 and Asheim et. al3. are incorporated to have a more realistic wellbore model. And finally, it is used the mechanistic model of Xiao etal.4, to compute the pressure drop and void fraction along the horizontal well.

With the proposed model, specifying the pressure at the heel of the wellbore we investigate the influence of using different methods for the friction factor evaluation, density and position of perforations, presence of inertial effects in the reservoir, gas-oil ratio, well diameter, oil viscosities, and pressure level at the wellbore heel. The infinite-conductivity and uniform flux assumptions are analyzed under multiphase flow conditions.
Studying Vugular Rocks By-Constant-Rate Mercury Injection
Authors: Gaulier C.
Published: December 2007

Constant-pressure stages are used for determining capillary pressures by mercury injection (Purcell's method). However, this does not always reveal the existing vugs. In practice, knowing the degree of vugular porosity practice, knowing the degree of vugular porosity is extremely useful when an immiscible drive recovery method is used.

This paper describes an automatic device for measuring neck radius size and distribution as well as for determining vugular volumes. The method consists of injecting mercury at a constant rate into a rock sample. The pressure and injected volumes are recorded simultaneously and the data are numerically processed.

The injection rate must be sufficiently slow for the pressure loss caused by flow inside the rock to be negligible in the face of capillary pressure variations occuring at the interfaces pressure variations occuring at the interfaces moving inside the rock.

Before reaching a vug the pressure increases to a high enough value for the free surface of the mercury to cross through the vug neck. Then when the mercury arrives in a vug, the diameter of the meniscus gets larger and the pressure decreases according to Laplace's law. When the vug is filled up, pressure returns to its initial value. The difference between the volumes injected just before the pressure drop and the volumes after pressure has returned to its initial value, determines the volume injected into a vug or group of vugs controlled by a given neck radius. In this way a distinction can be made between vugular saturation and matrix saturation, and thus vugular saturation distribution can be determined versus both the total saturation and the neck radii.

The device used for this is described. The relative importance of pressure levels (capillary pressure and pressure loss) used is discussed pressure and pressure loss) used is discussed The method of interpreting the curves is explained, and results obtained with different samples are presented.

Introduction

In all oil recovery methods, the texture of the rock matrix is certainly of great importance even though its knowledge is still limited. In particular, it is known that the displacement of one fluid by another is different in a homogeneous and in a heterogeneous rock. Nevertheless, the present lack of sufficiently sophisticated forecasting methods to account for heterogeneities should not prevent measurement techniques from being developed, for providing a better definition of porous-medium providing a better definition of porous-medium geometry.
Deep-Well Disposal of Steel Pickling Acid
Authors: Bayazeed A.F. , Donaldson E.C.
Published: December 2007

Several aspects of subsurface disposal of waste pickle liquor (WPL) are presented from a survey conducted by Bureau of Mines engineers. Both hydrochloric and sulfuric acid waste pickle liquors are being injected into deep wells. These wastes require that acid-resistant material be used in storage, filtering, and pumping operations. In Illinois and Indiana, WPL is injected into the Cambrian age Mt. Simon sandstone formation. The Mt. Simon sandstone in these States ranges up to 1,800 ft thick and has an effective porosity of 12 percent and an absolute permeability ranging from 75 to 400 md. The average depth of WPL disposal wells is 4,000 ft, and injection is usually by gravity flow at rates as high as 2,000 BPD.

Completion of the disposal wells deviates from standard petroleum engineering practice in several ways. Extra strings of practice in several ways. Extra strings of casing are cemented to the surface to offer greater protection of fresh water zones, water is pumped through the annulus of the injection tubing and casing for protection against corrosion, and electrodes are used at the bottom of the casing to monitor the acidity of the fluid in the annulus.

Introduction

The steel industry has adapted the petroleum technology of subsurface disposal petroleum technology of subsurface disposal of brines to the disposal of waste steel pickling acid. The underground injection pickling acid. The underground injection of waste pickle liquor (WPL) by the steel manufacturing companies commenced in 1965 as the cost of surface treatment and emphasis on surface pollution from waste chemicals increased. Prior to 1965, the WPL was treated by neutralization, sedimentation, and sludge disposal. Many acres of valuable company land had to be used for sludge disposal. The steel companies that have turned to subsurface waste disposal to solve their waste acid disposal problem are located in the North central and Eastern states as shown in Fig. 1.

Hartman states that subsurface disposal of WPL has proved to be economically feasible for the steel industry. The capital investments maintenance, and operating costs of subsurface injection systems are each one-third to one-fifth the cost of surface treatment and disposal. When properly designed, maintenance is negligible and the system can be operated under automatic control for an indefinite period. In addition, very little plant area is required for subsurface waste disposal systems.