bluuebunny/crossref_metadata_2025 huggingface dataset:
NORM Scale Formation: A Case Study of the Chemistry Prediction, Remediation, and Treatment in Wells of the Antrim Gas Field
Authors: Oddo J. E. , Sitz C. D. , Ortiz Isais , Linz D. G. , Lawrence A. W. , Kan A. T. , Tomson M. B.
Published: December 2007

BaSO4 scale containing Naturally Occurring Radioactive Material (NORM) as well as calcium carbonate scale has been reported in gas production facilities in conjunction with the Antrim play in northern Michigan. The scale study was undertaken by the Water Research Institute, Inc. (WRI) under contract from the Gas Research Institute. It was proposed in the scale study to conduct a two phase systematic characterization of BaS04 scale from the Michigan Basin area both as to occurrence and environmental hazard, and to evaluate scale control methods using brines typical of the area. The initial study involved sample collection and analytical work-up to arrive at a correct theoretical analysis of the problems involved. The variability of the sulfate concentrations in the wells is addressed and scale prediction techniques applied to the reservoirs and the surface equipment to determine where scale was forming and where it is likely to form. The scale is proposed to be forming due to the commingling of produced waters from wells with high sulfate concentrations with waters from other wells relatively high barium concentrations. Inhibitor evaluations were done using a high temperature-pressure laboratory apparatus developed at Rice University and WRI (patent application pending with GRI) and effective chemicals and probable dose rates for inhibition were determined. Concurrently, studies were begun by Bioindustrial Technology, Inc. and United Exploration and Development Consultants to learn the sources of the high sulfate concentrations reported in some wells in the area and to determine the causes of souring in some others.

In addition to the scale forming in the surface facilities, NORM scale was predicted and found in production tubing from individual wells. The driving forces for scale precipitation in these wells is the temperature and pressure changes resulting from production Chemical squeeze of inhibitor into the reservoirs and surface injection are recommended to treat and eliminate the scale problem
NORM In Produced Water Discharges in the Coastal Waters of Texas
Authors: Taylor Windle
Published: December 2007

The Louisiana Department of Environmental Quality has reported elevated levels of naturally occurring radioactive material (NORM) in some discharges of waters produced in association with oil and gas production in Louisiana.1 Also, a NORM survey conducted by the American Petroleum Institute (API) found elevated NORM levels in production equipment in certain geographical areas of Texas.2 The Railroad Commission of Texas (RRC) became concerned about the possibility of elevated levels of NORM in produced waters being discharged to surface waters in Texas. However, the Railroad Commission realized it did not have the staff resources to undertake a massive NORM study. Therefore, RRC staff sought a means to utilize existing data to predict NORM levels in produced waters discharged in Texas. Barium is required to be reported as part of the RRC's discharge permit application. Barium is chemically very similar to radium. Therefore, RRC staff felt there might be a relationship between barium and radium levels in produced waters.

A NORM survey was conducted on produced waters being discharged along the coast of Texas. Thirty-five discharges were selected for this survey based on their geographical location and varying concentrations of barium in their produced water discharges. The operators responsible for these discharges were asked to sample and test the discharges for certain chemical parameters, and to determine radioactive exposure levels in these discharges. In addition, the responsible operators were asked to submit geographical and geological information relevant to their discharges.

The information supplied by operators was studied to determine whether correlations existed between radium 226 and other chemical constituents of produced waters. Geological information was also studied to try to determine if geologically "hot" formations could be identified. The studies showed that the Frio formation produces water with higher NORM levels than the Miocene formation. No direct relationship between barium and radium 226 could be found, but test analyses did show that a relationship exists between total dissolved solids and radium 226. This relationship was used to project levels of radium 226 in other active produced water discharges along the Texas coast.
Continuous Flow Measurement of Glycol Reboiler Still Column Vents
Authors: Parker K. E. , Brennan T. M.
Published: December 2007

Emissions from the still columns on glycol reboilers are comprised of water vapor and various sulfur and hydrocarbon compounds. These compounds include substances such as benzene, toluene, ethylbenzene, xylene isomers, formaldehyde and hydrogen sulfide that are subject to state and federal toxic air emissions regulations.

Under the implementation of California's Air Toxics "Hot Spots" Information and Assessment Act of 1987, the local air district required quantification of glycol reboiler still column emissions based on in situ vent testing. Glycol reboilers are particularly difficult to source test due to velocity fluctuations, temperature cycles and low flow, which are inherent in the glycol dehydration process. Reboilers cycle between high and low fire in order to maintain the temperature of the glycol within a specified range. The alternating firing cycle results in variable exhaust temperatures and volumetric flow rates.

Pollutant mass emissions are calculated as a product of the gas concentation and the volumetric flow rate. The variable temperatures and volumetric flow rates common to the reboiler process may adversely affect volumetric flow measurements and, consequently, the resultant emission measurements.

Volumetric flow rates obtained with various instruments were compared to determine the most suitable measurement technique for low-flow reboilers. These instruments included a hot wire anemometer, a vane anemometer, a pitot tube and an orifice meter. The use of a continuously-monitored orifice flowmeter yielded accurate, integratable volumetric flow data and defined a repeatable and quantifiable temperature and flow profile. This procedure also enabled the stack tester to obtain a representative, integrated sample over one or more complete cycles and established a maximum sampling rate.
Air Emissions Trading
Authors: Frederick J. D.
Published: December 2007

With the enactment of the New Clean Air Amendments, the regulations being promulgated nationwide on both state and local levels for inclusion in state implementation plans are relying to a large extent on the use of air emissions trade programs similar to those developed in the state of California. Exploration and production companies will have to operate and develop enhanced recovery techniques and maintain competitiveness in the world market while complying with the emissions trading regulations. In addition, production companies represent a substantial offset pool which will project them into the broad-based business development cycle.

The emissions trading or offset programs being proposed are taking various forms; some are informal, some are contract-based, and some are certificate-based. Each of these trading program methodologies or philosophies are examined. The broad experience in the state of California is utilized to identify beneficial aspects of the programs.

The emerging offsets trading regulations are analyzed. The optimum logic analysis results in a call for a standardized offsets trading scenario which will allow for maximum progress towards attainment of the Clean Air Standards within a functional business environment.
Pilot-Unit Testing of the R-BTEX Process
Authors: Gamez J. , Rueter C. , Thompson P. , Lowell P.
Published: December 2007

As a result of increasing regulatory pressure, emissions of benzene, toluene, ethyl benzene, and the xylene isomers (BTEX) and other volatile organic compounds (VOC) from the regenerator still vent of glycol dehydration units have become a major concern of the natural gas industry. The Clean Air Act Amendments (CAAA) of 1990 have provided an impetus for air toxics regulations, and several states are regulating or considering regulating these units. To address this issue, the Gas Research Institute (GRI) and Radian Corporation have initiated research in three areas related to these emissions: the development of sampling and analytical methods, emissions modeling, and emissions control.

This paper contains background information on glycol dehydration units, their emissions, and legislation pertinent to these emissions. It also discusses the R-BTEX process for controlling emissions and the results of initial field experiments.
Initiating an Audit Program: A Case History
Authors: Guckian W. M. , Hurst K. G. , Kerns B. K. , Moore D. W. , Siblo J. T. , Thompson R. D.
Published: December 2007

In the early spring of 1990, the management of Atlantic Richfield Company (ARCO) issued a directive to the six operating units of the corporation to begin a program of audits to assure compliance with all applicable environmental, health, and safety (EH&S) regulatory requirements. The time frame given to complete the first cycle of compliance audits was three years.

ARCO Oil and Gas Company (AOGC), the domestic exploration and production (E&P) unit of ARCO, responded to the management directive by assembling an EH&S audit staff, developing audit procedures, and creating a database of about 3000 audit protocols. More than two-thirds of the required audits were completed at the time this paper was published, including audits of gas plants, oil and gas production operations, drilling operations, high rise office buildings, offshore platforms, and warehouses. Selective use of contract employees allowed the program to stay on a tight schedule.

The purpose of this paper is to describe the steps taken by AOGC in developing its audit program, outline the obstacles overcome in implementing the process, and review costs and other important aspects of the program.

Specific areas of the audit program addressed in the paper include: pre-audit planning, statistical sampling guidelines, on-site activities, written reports, follow-up requirements, and database management.
Guidelines for Designing Safe, Environmentally Acceptable Downhole Injection Operations
Authors: Andersen E. E. , Louviere R. J. , Witt D. E.
Published: December 2007

Downhole cuttings injection technology is used by many operators to dispose of drilled cuttings generated when using oil base mud (OBM). These operators have worked with service companies to develop systems designed to slurry drilled cuttings and to inject the prepared slurry down a wellbore and into the formation.

Developing sound slurrification methods has played an important role in expanding the utility of cuttings injection. However, a clear understanding of what happens downhole during cuttings injection operations is critical to successfully implementing this technology. A set of guidelines are presented to assist operators and regulators when evaluating the merits of potential downhole cuttings injection applications. The guidelines are useful not only from an engineering perspective, but also from a regulatory viewpoint since the guidelines address the majority of regulatory concerns.
Analysis of the Rate of and Reasons for Injection Well Mechanical Integrity Test Failure
Authors: Browning L. A. , Smith J. D.
Published: December 2007

An operator of a Class II injection well (i.e., used in conjunction with oil and gas production) is required to perform a mechanical integrity test (MIT) at least once every five years. We studied the rates of and reasons for failure of over 10,000 scheduled MITs, for a variety of completion types, in the States of Louisiana, Michigan, Nebraska, and Pennsylvania, over two 5-year MIT cycles. The failure rate for State/cycle combinations ranged from 3 percent to about 12 percent for scheduled MITs. However, we found that the actual rate of well failure was at least 50 percent greater, considering the rate of reported well failures in service and evidence of operators pretesting and repairing wells prior to the scheduled MIT. We found that the primary reason for MIT failure was casing failure (45 percent to 85 percent of State failures), compared to tubing, packer, or wellhead failures. Over 26 percent of wells with casing failures were plugged within 60 days of the test, which suggests problems of a more serious nature. For about 22 percent of the wells with casing failures, the failure involved the only layer of protection, and it allowed waste to be injected outside the wellbore.
Making the Most of Endangered Species Compliance: Development of the Coles Levee Ecosystem Preserve
Authors: Wolfe M. H. , Gelbs T. R.
Published: December 2007

Endangered species compliance has become increasingly difficult in Southern California, particularly in the Southern San Joaquin Valley which supports more rare species than any other area in the lower 48 states. As development has proceeded for many years without establishment of significant habitat preserves, increasing numbers of species are being proposed and listed as endangered. Development of the Coles Levee Ecosystem Preserve (Preserve) by ARCO Oil & Gas Company (ARCO) benefits endangered species, habitat conservation, and industry.

The Preserve was established with a conservation easement over approximately 6,059 acres. The easement was deeded to the California Department of Fish and Game. ARCO will continue its oil and gas activities on the Preserve and will manage the surface for the benefit of the rare and endangered plant and animal species that inhabit the property. Upon abandonment of the oil and gas operations, the developed areas will be reclaimed for wildlife habitat.

The Preserve provides specific economic benefits to the company and benefits habitat, conservation, and the environment in general. These benefits to the landowner include assurance of the ability to conduct exploration and development activities due to a streamlined permitting process, a fifty percent cost savings in providing endangered species compensation acreage, certainty that compensation acreage will be available, and sales of excess endangered species compensation to third parties.

Management of the Preserve by the private landowner is an unprecedented occurrence in California Department of Fish and Game policy. Private/public partnerships of this type will be the key to solving future environmental issues. The development of the Preserve is a win-win situation for industry and conservation.
Reclamation Procedures for Produced Water Spills from Coalbed Methane Wells, San Juan Basin, Colorado and New Mexico
Authors: Kaszuba J. P. , Buys M. W.
Published: December 2007

Most natural gas wells completed in the Fruitland Formation in the San Juan Basin produce large volumes of water that contain elevated levels of total dissolved solids (TDS), sodium, and chloride. The chloride and sodium content of this water can elevate soluble salt and exchangeable sodium levels in soil. Soil most severely impacted by discharge of this produced water is saline-sodic. It will not sustain plant life until action is taken to reduce the levels of soluble salt and exchangeable sodium in the soil.

Reclamation of impacted soil should take place promptly and consist of applying gypsum amendments and native grass mulch or aged manure followed immediately by leaching. The leach water should be impounded on the spill site if the topography is suitable. In New Mexico, seeding of salt-tolerant grasses and shrubs should take place between July 1 and September 15. Revegetation strategies for Colorado are more complex because topography and rainfall range dramatically.

Reclamation will proceed slowly and beneficial results will not be observed for at least 6 months to 1 year. Complete soil reclamation and restoration of vegetation may not be accomplished for 3 to 5 years after initial application of amendments.
Shelter in Place: The Technical Basis for Its Use in Emergency Planning
Authors: South B. C. , Herries P. E. , Byrd W. R.
Published: December 2007

This paper describes the technical basis for the Shelter In Place concept and its applicability to emergency planning in a populated sour gas production area, including:

A general description of the operating area and emergency planning considerations, including road maps overlain with adjacent population and field' facility information; Worst case scenario selection, including gas release rates, exit gas velocity and wind velocity; Gas dispersion modeling, including transient and steady-state results and timing; Air infiltration testing of buildings, including a description of the ASTM test method utilized and test results of local businesses and residences. Resulting safe time calculations, including internal H2S concentration versus time plots.

The paper also presents some case studies where shelter in place was effective in saving lives and other examples where lives were lost from failure to shelter in place.
Mercury Contamination at Gas Industry Sites
Authors: Charlton D. S. , Beaver F. W. , Butler R. D. , Harju J. A. , Hassett D. J. , Henke K. R. , Monson L. L. , Kuhnel Vit , Schmit C. R. , Stepan D. J. , Evans J. M.
Published: December 2007

The past and present use of mercury-filled flowmeters (manometers) at gas industry metering stations has resulted in contamination of soils with elemental mercury. These manometers are used throughout the gas industry at production wells, along pipelines, at gas processing plants, at underground storage facilities, and within gas distribution systems.

Soils contaminated with mercury at metering sites may be subject to Resource Conservation and Recovery Act (RCRA) regulations if a sample of the excavated soil exceeds 0.2 mg/L of mercury by the U.S. Environmental Protection Agency (USEPA) toxicity characteristic leaching procedure (TCLP) analysis. Under the Land Disposal Restrictions (Land Ban), mercury-contaminated soils that are determined to be hazardous by TCLP analysis (D009) cannot be landfilled without meeting certain treatment standards. For high-mercury soils (greater than 260 mg/kg total mercury), the Best Demonstrated Available Technology (BDAT) is specified as roasting or retorting.

The mercury research program at the Energy and Environmental Research Center (EERC) is part of a broader, multidisciplinary effort to investigate potential contamination of soil and groundwater at gas industry sites. The primary tasks of this mercury research program include 1) the conduct of a mercury workshop for the gas industry; 2) a literature review and development of a bibliographic database; 3) an assessment of computer models applicable to mercury migration; 4) the development of a risk assessment model for mercury-contaminated sites; 5) the evaluation of sampling, preservation, and analytical protocols for mercury; 6) the characterization and monitoring of field sites; 7) the conduct of laboratory experiments evaluating leaching techniques; and 8) an evaluation of the application of existing or developing remediation technologies with mercury-contaminated soils.

Several of these tasks have been completed, resulting in the distribution of proceedings of the mercury workshop and the bibliographic database. Four field sites have been characterized, and monitoring wells are continuing to be sampled. A mobile prototype of a remediation technology based on physical separation has been tested. Three additional technologies (thermal, chemical, and physicai/chemical) will be tested at the bench scale or as prototype units in early 1993. Most other tasks have resulted in reports that are currently in draft form and will be published in 1993.
Interpreting Soil and Groundwater Data with Respect to the Natural Distribution of Contaminants: A Case Study
Authors: Baker T. P. , Moore T. J.
Published: December 2007

Identifying the sources of contamination at a site often requires interpreting significant quantities and types of environmental data. When groundwater studies are performed near secondary recovery operations, and it is determined that the groundwater has elevated chlorides, our investigations may hastily evolve from the preconceived assumption that chlorides from the injection of produced water caused the elevated groundwater chlorides.

This paper uses a case study to illustrate how "multiple working hypotheses" were used at the Northeast (N.E.) Fitts, Oklahoma, waterflood operation to avoid a narrowly focused groundwater investigation. The study demonstrates that interpretation of data with respect to the natural distribution of potential contaminants can result in more accurate identification of contaminant sources in groundwater.

Using the multiple working hypothesis approach, data which previously suggested oilfield contamination now clearly illustrate that groundwater chlorides were naturally occurring. Supporting evidence included increasing salts with depth, differences in salt composition, and the observation that time dependency of groundwater salt concentrations resulted from monitor well construction and development.
Even if You're on the Right Track, You'll Get Run Over if You Just Sit There: Source Reduction and Recycling in the Oil Field
Authors: Savage L. L.
Published: December 2007

In the oil field of the past, companies generally concentrated the bulk of their environmental resources on efforts to dispose of wastes after they were generated. Managing the large quantities of produced waters, drilling fluids, and other wastes associated with oil and gas exploration and production activities was perceived as an unavoidable problem. However, regulations regarding oil and gas waste management are becoming increasingly stringent. Costs for disposal of these wastes are also increasing, not only in terms of disposal fees, but also in terms of potential liability. And concern over the public health and the environment is increasing. Today, in order to economically comply with regulations, protect the environment, and limit potential future liability, companies must shift the focus of their waste management programs. These companies must begin to focus on the numerous source reduction and recycling opportunities that exist for all types of oil and gas operations. This paper explores several source reduction and recycling options for oil and gas operators, many of which are relatively simple and inexpensive.
Waste Minimization Program at Sour Gas Facilities
Authors: Benoit J. R. , Schuh M. G.
Published: December 2007

Although the Oil and Gas industry in North America has enjoyed various exemptions from hazardous waste regulations over the years, these regulations are changing and more emphasis will have to be placed on minimizing wastes from the production of oil and gas. As a result a Waste Minimization Program has been developed for application at Mobil's sour gas plants in Western Canada. The Program consists of a multi-phased approach where the primary focus is on the Waste Audit which is the first step in reducing waste.

The paper will provide an overview of the various phases of the program including the development of the waste flow diagram and the material balance study. Procedures for identifying waste reduction alternatives and ranking criteria will also be discussed as well as suggestions for a cost/benefit analysis and implementation plan. Emphasis on the approach, audit team selection and expectancies from the program will be reviewed.

To date the program has been implemented at five(5) sour gas plants in Western Canada. The paper will present some of the results from the program and outline minimization options that have been implemented with success. The program has already yielded a 30% reduction in solid and liquid wastes at many of these facilities.
Waste Oil Source Reduction for Diesel Engines
Authors: Reller C. E.
Published: December 2007

Waste oil source reduction was accomplished on remote site diesel engines by extending oil change intervals using portable field monitors. Incidents of normal and abnormal oil degradation were recorded and correlated between field and laboratory tests. A quality assurance, program evaluated data precision and accuracy.
Microbiologically Influenced Souring in Gas Industry Facilities
Authors: Pope D. H. , Dziewulski D. M. , Morris E. A. , Paakkonen S. T.
Published: December 2007

Microbiologically influenced souring (MIS) has been defined as the presence of sulfide in produced gas or fluids due to current microbiological activities. Several important problems related to souring include the removal of H2S before transport or end-use, H2S corrosion, safety, environmental concerns, and the costs associated with these problems. Over the past several years, the Gas Research Institute (GRI) has sponsored research on souring in production and storage facilities. Research at storage facilities has led to the development of initial profiles, detection kits (MISKITS), and field guides, as well as chemical and microbiological databases. Souring investigations at production facilities have addressed the extent of souring in the United States and potential cost savings. Also, localized souring in the Antrim formation in the Michigan basin has been investigated, the results of which suggest souring due to current MIS.
Precipitation of Asphaltic Sludge During Acid Stimulation Treatment: Cause, Effect, and Prevention
Authors: Suzuki Fumiko
Published: December 2007

This paper discusses the detrimental effects of sludge formation during acid stimulation treatments, and our experience in preventing the problem. Acid sludging in some oils in the US, particularly in California and the Rocky Mountain Region, has been reported in the literature in the mid 60’s1. In the early 1980’s, when incidents were reported independently in the company’s three different fields in central Alberta, we began to investigate the extent of the problem.

Our tests show that crude oil from all the company’s fields, scattered across western Canada, has strong tendencies to form sludges when the crude is in contact with a strong acid such as 15% HCl, and the conventional anti-sludge additives are ineffective in controlling it. Sludging is especially severe when Fe is present in the acid. The major source of Fe is corrosion and mill scales in the tubing.

Both field and laboratory observations indicate that sludging can cause serious plugging in the formation, leading to ineffective acidizing. Effective sludge control was difficult in the early days, as the technology was new to the industry. However, with close co-operation with the service industry, notable progress has been made, and currently, sludging can be controlled economically in the presence of up to 40,000 ppm Fe in HCl up to 28%.
Predicting the Production Performance of Hydraulically Fractured Oil Wells
Authors: Hrachovy M. J.
Published: December 2007

This paper investigates the equations governing well performance for hydraulically fractured wells producing from solution gas drive oil reservoirs. A method is presented which permits prediction of the folds of increase and the corresponding oil production rate obtained by fracturing until the economic limit is reached.
Produced Water Chemistry Points to Damage Mechanisms Associated With Seawater Injection
Authors: Braden J. C. , McLelland W. G.
Published: December 2007

Producing well water samples from the Prudhoe Bay Eastern Operating Area were evaluated with respect to the fraction of seawater in the sample. The evaluation demonstrated that the previous method of using magnesium or sulfate to determine percent seawater was in error. Because the water contains acetic acid, which was titrated as bicarbonate, scaling calculations overpredicted calcium carbonate scale formation.

The data show that there are at least two different waters in Prudhoe Bay. Additionally, potential reservoir mechanisms driving chemical reactions were identified as cation exchange (fines migration), scale precipitation (calcium carbonate, barium sulfate), formation dissolution and metabolic conversion of sulfate (leading to iron sulfide precipitation).
Pressure Buildup Techniques Applied to Identify Decreasing Fracture Stimulation Performance
Authors: Frailey S. M. , Crawford G. E. , Pierce A. E.
Published: December 2007

Fracture stimulation characteristics were measured and studied for changing behavior over a 6 month period using pressure buildup tests conducted on a Prudhoe Bay well. The suite of pressure tests included a pre-frac buildup, and two post-frac buildups at six month intervals following the fracture stimulation treatment. Pre-frac analysis exhibited radial composite characteristics consistent with other Prudhoe Bay well test analysis. Post-frac analysis showed the fracture length and conductivity to decrease over a six month period. Corroborating the well test results, production from this well decreased more rapidly than expected. Numerical simulation confirmed the results. Data acquisition pertinent to a successful well test analysis is discussed.
Permeability Evaluation in Heterogeneous Formations Using Geophysical Well Logs and Geological Interpretations
Authors: Ameri S. , Molnar D. , Mohaghegh S.
Published: December 2007

Permeability is the key parameter for reservoir characterization. The permeability of the formation is usually evaluated from the cores and/or well tests. It should be noted that cores and well test data are often only available from few wells in a reservoir while the well logs are available from the majority of the wells. Therefore, the evaluation of permeability from well log data represents a significant technical as well as economic advantage.

The evaluation of permeability in heterogenous formation from well log data however represents a difficult and complex problem. Generally, a simple correlation between permeability and porosity cannot be developed in heterogenous formation. The goal of this study has been to develop a generalized methodology to determine the permeability of a heterogeneous formation utilizing geophysical well logs as well as other geological information.

Granny Creek Field in West Virginia has been selected as the study area in this paper. This field has produced oil from Big Injun Formation since early 1900's. The waterflooding operation was initiated in 1970's and currently is in progress. Well log data are available on substantial number of wells. Core samples are also available from a few wells. Core samples and the well logs were analyzed to determine permeability, porosity and water saturation. The results of core and log analysis were complemented by geological interpretations to develop a correlation between permeability and well log responses. The results presented in this paper could serve as a guideline for correlating permeability with well logs responses in heterogeneous formations. A systematic and synergetic approach which integrating data from various well logs as well as depositional, lithological and sedimentological interpretations has been developed to evaluate the permeability.
Improved Oxygen Activation Logging for Waterflood Surveillance Measurements
Authors: Schnorr D. R. , Targac G. W. , Guillory R. J. , Pearson C. M. , Eck M. E.
Published: December 2007

This paper reports the results of using an improved impulse oxygen activation logging tool for water flood surveillance in the Kuparuk River Field, Alaska. The modified logging tool now enables the monitoring of water injection profiles in the "selective single" well completions over a wider range of injection rates with better vertical resolution when compared with an earlier impulse oxygen activation tool configuration.

The resolution and dynamic range of this service have been improved with a modification to the pulsed neutron tool. The modification increased the vertical resolution at high injection rates from 15-ft to 6-ft. Using a series of station measurements, it is possible to measure water velocities from less than 2 ft/min (0.01 m/s) to 300 ft/min (1.5 m/s). Knowing the cross sectional area of the casing/tubing annulus, water flow rates from 10 to 9500 BWPD are directly calculated.

These measurements have provided injection profiles to determine vertical conformance and the need for profile modification. Three case histories are discussed. 1.) The results of the pre- and post-logging programs are presented as well as the results of the successful profile modification. 2.) Detection of thin high permeability thief zones. 3.) Multiple water velocities measured in the same direction at same time to determine the injection profiles inside and outside of the tubing. This has all been possible with the successful modification of the WFL* tool to increase its vertical resolution. Impulse oxygen activation logging has become crucial to the continued surveillance of the secondary recovery project of the prolific C Sand in the Kuparuk River Field. Additionally, the information could be used to make an assessment of ultimate recovery, the need for infill drilling and enhanced recovery processes.
New Electronic Measurement System Enhances Slickline Service Capabilities
Authors: Larimore D. R. , Kerr W. L. , Hulme P. L.
Published: December 2007

This paper will describe a new electronic measurement system that maximizes the efficiency of slickline operations by providing greater depth-measurement accuracy than previously possible. Conventional systems employ mechanical measurement devices that cannot make measurement adjustments for environmental or physical stress factors; for this reason, depth measurements do not provide absolute accuracy. Through use of a recently-developed electronic counter, this new measurement system has the capability to make the needed adjustments to address this problem.

The continuous need for cost efficiency in today's oil and gas industry has made depth measurement accuracy more critical for service operations. Through continuous high-speed depth adjustment and data transmission capabilities, this system fulfills today's accuracy needs and extends use of slickline beyond the limitations of simple mechanical measurement systems.

Through the results obtained from testing and case histories, the paper will address the practical benefits and features for improved depth measurements. These include: Depth-measurement accuracy for all commonly used slicklines and braided lines.Measurement corrections for stretch resulting from line tension and temperature effects on counter wheel.High-speed microprocessing compatible with slickline speeds.Retrieval of depth and time information for use with downhole memory production surveys.Use of the system for downhole memory tool surveys as a cost-effective alternative to electric-line logging.

High speed resolution and data retrieval make this system more sophisticated than any other offered for slickline well servicing. Additional testing indicates that planned electronic development will further increase the scope of slickline for well servicing by providing even greater efficiency and versatility.
The Petrophysical and Geological Impact of Borehole Images
Authors: Bigelow E. L.
Published: December 2007

Formation images from wireline measurements have reached maturity. Corroborated by numerous comparisons to core, the images are considered to be an acceptable substitute for core in the absence of core data. Since 1985, the geological impact of these services is self-evident, but attributes of imaging logs can also lead to more efficient petrophysical analysis.
Modeling the Effect of Imbibition Capillary Pressure in Heterogeneous Porous Media: Waterflood Recoveries of the Romeo Interval, Prudhoe Bay Field
Authors: Angert P. P. , Begg S. H. , Sallak N. H.
Published: December 2007

Advances in the development of geostatistics and object modeling, have allowed the construction of numeric representations of the Zone 1 interval, Ivishak Formation, Prudhoe Bay Field, that retain the character of the porosity / permeability seen in conventional core data. Modeling of the distribution of imbibition capillary pressure forces associated with these heterogeneous distributions was accomplished via the conventional Leverett J-Function.1 Subsequent water / oil fluid flow simulation, has revealed the effect of capillary forces on recoveries to waterflood.
The Application of Gas-Lift Injection Pressure-Operated Spring Valves in the Western Operated Area of the Prudhoe Bay Field: A Case Study
Authors: Vigil G. R. , Nordlander G. S. , Valencia R. L. , Watkins J. O.
Published: December 2007

Recent advances in injection pressure operated gas lift spring valve technology have proven to be beneficial in the Western Operated Area (WOA) of the Prudhoe Bay Oil Field. The temperature independent nature of the spring valves combined with their ability to operate at injection pressures as high as 2400 psig at valve depth make them the proven choice over conventional bellows charged gas lift valves. This cost effective technology has simplified both gas lift design and operation in the WOA. Two case wells which exemplify the benefits derived from the utilization of spring valve technology are described in this paper.
Quality Assurance: Bellows-Operated Gas-Lift Valves
Authors: Lagerief D. L.
Published: December 2007

A gas lift valve quality assurance program has been in place for the Eastern Operating Area (EOA) of Prudhoe Bay, Alaska since 1981. The program has involved data gathering, analysis and direct involvement by the field operator in the set-up of live gas lift valves.

The quality assurance program results have prompted a change in gas lift design methodology. Future gas lift designs will incorporate higher pressure drops between unloading valve surface closing pressures to avoid valve interference. Gas lift valve vendors have been given important feedback on minor problems that appear to be supplier specific. The design modifications, vendor equipment modifications, and valve set-up changes resulting from the quality assurance program have improved the reliability of Prudhoe EOA gas lift designs.
Experimental Study of an Environmental Remediation of Gulf Coast Crude-Oil-Contaminated Soil Using Low-Temperature Thermal Treatment
Authors: Alcocer C. F. , Chowdhury H. R.
Published: December 2007

Laboratory research was conducted to study the remediation of crude-oil-contaminated soil under the "Low-Temperature" burner system. Low temperature burner systems are those which operate below or up to 650°F whereas, those above 650°F are called "High-Temperature" systems. In this study, the effectiveness of remediation processes at three different levels of operating temperatures of 300°F, 650°F, and 2,000°F and three different levels of retention times of 2, 15, and 30 minutes in the burner were investigated. Twenty-nine experimental tests were performed using four different types of oils. The result of the initial soil test showed less than 100 ppm Total Petroleum Hydrocarbon levels. Before Weatherization of four different crude-oil-contaminated soils, the results of Total Petroleum Hydrocarbon (TPH) levels for sample numbers 5318, 5331, 5332, and 5351 were measured 45,000 mg/kg, 26,000 mg/kg, 27,000 mg/kg, and 29,000 mg/kg respectively. After Weathering the samples for two weeks, (average high and low temperatures were recorded at 77.6°F and 67.1°F respectively); the results of TPH levels for sample numbers 5318, 5331, 5332, and 5351 were measured 32,000 mg/kg, 19,000 mg/kg, 15,000 mg/kg, and 28,000 mg/kg respectively. Then After Ashing by combustion, the experimental results of TPH levels for sample numbers 5318, 5331, 5332, and 5351 at 650°F and 30-minutes retention time were measured 980 mg/kg, 3,400 mg/kg, 2,700 mg/kg, and 2,900 mg/kg respectively. Tests conducted in this study include sonication to agitate sample for disrupting cells, bacteria, or tissues; infrared detection to measure TPH levels; and combustion to burn all hydrocarbons. Based on the results of this tests, the study suggested that the cleanup or remediation of hydrocarbon/or non-hydrocarbon compounds by "Low-Temperature" burner system are possible but only at high retention time. The retention time required to achieve this remediation process range from 49, 52, 53, and 52 minutes respectively (figures 1.1-1.4). For the "High-Temperature" burner system, the result of this study showed that at two-minutes retention time, the total remediation of oil-contaminated soil required the burner temperatures of 3,100°F, 2,900°F, 2,600°F, and 3,100°F for sample numbers 5318, 5331, 5332, and 5351 respectively (figures 1.5-1.8). The remediation of petroleum-contaminated soil under low temperature system is technically feasible but may not be economically practical because of the long retention time required to achieve the goal.
Windowing Systems Enhance Computer Simulation
Authors: Fife L. D. , Henry S. R.
Published: December 2007

Historically, simulation has been performed on mainframe computers, obtaining input through a text file. Creation of the input data file was error prone, and use of the simulator was often difficult. Debugging an input file containing erroneous information was difficult and time consuming. When error checking occurred, it was often within the simulator and fatal errors would result in wasted execution. These computer systems were often remote and expensive to use.

The increased speed and capacity of computers allows simulations to be performed on increasingly complicated problems. Application research allows processes to be represented more precisely. As simulators and computers become more complex, creation and debugging of input data files becomes more difficult. The difficulty of required simulations, coupled with the enhanced speed and capacity of available machines, increases the difficulties associated with interfacing the engineer with the simulation and data file creation processes.

In particular, the availability and capacity of desktop computers eliminates the need of mainframe computers for many simulators. This solves many of the cost problems associated with remote mainframe computers. However, the human-machine interface provided under desktop computer operating systems is not a significant improvement on the mainframe environment.

Using a graphical user interface (GUI) can improve the environment encountered by the engineer, provide sophisticated data checking, and provide other enhancements to the simulation process. The GUI can offer solutions for many of the input file and data error difficulties.
PC-Based Cement Job Simulator Improves Primary Job Design
Authors: Kulakofsky David , Henry S. R. , Porter David
Published: December 2007

Until recently, cement simulation programs have been difficult to use, required large computer systems, and occasionally yielded results that were difficult to understand. Often the data input task was cumbersome enough to limit usage of these simulators. With the advent of Graphical User Interfaces (GUIs), even the most sophisticated simulator can be easy to use. With the wide variety of today's PC Graphics packages, complicated results can be made comprehensible through visual displays. This paper describes a technically advanced PC-based primary cement job simulator illustrating how a simulator can be sophisticated and easy to use at the same time. The simulator description includes recent enhancements, such as the capability to utilize temperature-dependent rheology and Critical Reynolds Number when calculating frictional losses.
Benefits of 3D Visualization to Reservoir Simulation
Authors: Austin A. Z.
Published: December 2007

This poster session will present the benefits of 3D visualization as applied directly to reservoir simulation pre-processing and post-processing. Scientific or 3D visualization has been traditionally used for architectural engineering, finite-element analysis and computational fluid dynamics running on CRAY super computers. With the recent improvements in computer performance, 3D visualization systems can now be operate practically on graphic workstations such as the HP/Apollo, IBM RS/6000s and Silicon Graphics.

It can be difficult to visualize three-dimensional flow through porous media based upon a two-dimensional representation of the actual three-dimensional flow. Add a highly faulted structure upon the porous media and the three-dimensional flow becomes even more difficult to assimilate. Furthermore, reservoir engineers are constantly asked to review more production scenarios or alternatives in shorter periods of time thereby necessitating their need for more effective ways to interpret their simulation results. The need to transform the vast amounts of simulation results into easily understood images is crucial to improving our effectiveness.

Highlights of achieved benefits as well as current problems with 3D visualization approaches to understanding reservoir simulation results will be shown.
Overview of Key Remaining Issues in Reservoir Fluid Properties and Phase Behavior for Successful Reservoir Development Applications
Authors: Pande P. K. , Meyer B. J. , Banthia B. S. , Lawal A. S.
Published: December 2007

The properties of reservoir fluids axe critical for the successful exploitation of petroleum oil and gas reservoirs. Integrated PVT sampling and testing programs are key to successful reservoir development applications. Recently developed laboratory measurements and advanced computational tools have enhanced knowledge of phase behavior and physical properties of reservoir fluids. However, many aspects of phase behavior remain unresolved.

This poster session highlights the integrative aspects of PVT programs and provides insights and solutions for unresolved problems. Issues covered include the following:

RESERVOIR FLUIDS SAMPLING COMPLEXITIES Sampling Under Dynamic Reservoir Conditions: Petroleum reservoirs are continually in a dynamic state. Thus, obtaining representative samples during any stage of depletion or development presents its own unique challenges. Case histories are provided of the pros and cons of bottomhole vs. surface sampling.Sour Crude Oil System Sampling: Sampling and laboratory testing of systems which contain hydrogen sulfide (H2S) deserve special consideration as absorption of H2S on the surface of sampling vessels can occur. This is of particular importance in studies of minimum miscibility pressure (MMP) since H2S is beneficial in lowering MMP for miscible hydrocarbon gas displacements.Condensate Fluids Sampling: Well conditioning for sampling of condensate fluids are critical in ensuring that representative fluids are obtained. The difficulty in obtaining representative samples results from liquid dropout of the condensate in the near wellbore region.Compositional Variation Within a Reservoir, Oil Fingerprinting: Utilization of oil fingerprinting, a chromatographic technique, represents a significant stride for reservoir surveillance and reservoir management of fields which contain multiple crude oils. The technique can be used as a production allocation tool for reservoir surveillance and is much more accurate and cost effective over conventional production logging techniques.
Prudhoe Bay Miscible Gas Distribution
Authors: Cockin A. P.
Published: December 2007

This poster covers the new methodology for miscible gas distribution described in SPE 241591 which was adopted by the Prudhoe Bay Unit in 1991 and has led to a 50% increase in the volume of oil being mobilized by miscible gas at Prudhoe Bay, The poster additionally covers the post expansion philosophy and the current status of the Prudhoe Bay Miscible Gas Project (PBMGP).

The PBMGP started in 1987 following a pilot in 1982. In its fully expanded form it has reserves in the range 410-480 million stb. The project is shown on Figure 1.

Miscible Injectant (Ml) rates of up to 450 mmscf/d have been achieved to date, after 1995 this should increase to a peak of 650 mmscf/d.