Summary Oily cuttings and waste fluid are byproducts of oil-based drilling muds. In such difficult drilling environments as the Gulf of Mexico, where oil-based fluids often are preferred, personnel safety, environmental, and economic concerns are exacerbated by the necessity to transport these cuttings and fluids to shore for disposal. This paper describes a process for on-site preparation and subsequent disposal of a slurry of cuttings by annular pumping. The disposal includes all cuttings and waste oil mud generated during drilling with oil-based fluids. Wastes are displaced down a casing annulus and into permeable zones below the surface casing setting depth. Descriptions of environmental and safety problems arising from onshore disposal, benefits of annular pumping, and equipment used for slurry preparation and pumping are described. This technique eliminates the need for platform cuttings storage, cuttings transportation to shore, and the environmental effects of onshore disposal. Introduction U.S. governmental regulations currently prohibit the discharge of free oil into the Gulf of Mexico during drilling operations. This ban on oil discharges has resulted in the necessity for operators to transport the waste mud and cuttings generated during drilling with an oil-based mud to an appropriate onshore waste treatment or disposal facility or to switch to exotic and sometimes unproved water-based systems. Although these water-based mud systems have not always failed, they have not proved to be fully acceptable alternatives to the oil-based systems they have displaced. Both economic and environmental considerations have dictated that more wells be drilled from fewer surface installations. As a result, more highly deviated and often horizontal wellbores have been drilled through the young, troublesome, water-sensitive shales that have plagued gulf drilling operations in the past.1 Successful drilling under these conditions in many areas of the gulf2 and other offshore environments3 requires the use of an oil-based fluid. Consequently, the implementation of an environmentally acceptable disposal method for oily cuttings and mud at the drillsite would reduce drilling costs and minimize the potential environmental exposure that would result from transport of this material to shore for disposal. Thus, a technique for converting the cuttings and mud into a slurry for slurry disposal by pumping it down the annulus of a well was developed. As this paper describes, annular pumping is the one-time displacement of drilling fluids and solids into a nonproductive, permeable zone (primarily sandstone) for disposal. Environmental Background The U.S. Environmental Protection Agency (EPA) regulates discharges from offshore oil and gas production facilities under the General National Pollutant Discharge Elimination System (NPDES) Permit No. GMG280000.4 These discharges are defined in the Oil and Gas Point Source Category of Title 40 of the U.S. Code of Federal Regulations (40 CFR 435). The permit allows the discharge of water-based drilling fluids and cuttings to the gulf, as long as the discharge does not result in a sheen on the ocean's surface (the so-called "no-free-oil restriction"). Additionally, the suspended particulate phase of the drilling fluid must pass a 96-hour toxicity test (LC50>30,000 ppm). Permit No. GMG280000 expired at midnight, Eastern Standard Time, July 1, 1991; however, the EPA published proposed Permit No. GMG2900005 for the western Gulf of Mexico. This permit places comparable restrictions on oil-based mud use and will, when finalized, replace the expired permit. As a result of these regulations, oil-based drilling fluids and the cuttings generated by drilling with these fluids cannot be discharged into the Gulf of Mexico. Consequently, the use of an oil-based mud system called for waste disposal in a commercial, onshore, nonhazardous oilfield waste (NOW)disposal location, where the waste is either buried or land-farmed. Historically, movement of drilling wastes to a NOW facility was not adequately tracked, nor was waste disposal well documented. Common industry practice included trucking mud and cuttings from offshore and onshore locations to the commercial facility. Often, the only records of these transactions were transportation and disposal invoices. Although these operations were conducted in accordance with applicable regulations, because non-NOW material was deposited at these sites, certain sites have been classified by the U.S. EPA as Comprehensive Environmental Response, Compensation, and Liability Act Superfund Sites. Remediation costs are shared by all who used the site for disposal regardless of the type of wastes taken to the site. The prohibition on the discharge of oil-based waste has caused a re-evaluation of the economic, safety, and environmental consequences of a "no discharge"offshore drilling operation. The associated expense, employee exposure to transfer operations, potential oil-spill cleanup exposure, and possible future liability of commercial NOW sites all have combined to create a need for an onsite disposal option. Because oil-based drilling-fluid systems have been the operational fluid of choice for drilling in the Gulf of Mexico, new procedures and techniques that would continue to allow the use of these fluids in the offshore environment have been sought. Oil-based-mud cuttings cleaning systems* have been developed, patented, and field tested. These systems, although operationally and environmentally sound, proved too slow to provide real-time treatment of generated waste and proved to be comparatively expensive for the offshore environment. Several efforts have been reported6–11to develop technologies that would render oil-based-mud waste suitable for offshore discharge. Cuttings washers, incinerators, and solvent-extraction systems all failed to produce environmentally acceptable effluents, were too expensive to use, or were considered unsafe for offshore application. Consequently, when the need for oil-based muds was identified, many operators relied on the on-site collection of the oily cuttings and mud in boxes. These boxes then were transported to shore by dedicated work boats, and the contents were buried in commercial NOW disposal facilities. Annular pumping for waste-water disposal has been used in several situations. In one application, drilled cuttings are recycled for use as road-building material and the water used to clean the cuttings is pumped into a permeable zone below the surface casing.12,13 In many areas, produced water routinely is pumped into production zones for EOR purposes.
Hydrogen damages equipment in several ways. Hydrogen attack, embrittlement, crack initiation and propagation, and other mechanisms are constant threats to equipment integrity. Ways to avoid these problems are discussed.
Summary Section 328 of the Clean Air Act Amendments of 1990 required the EPA to promulgate a rule establishing air pollution control requirements for Outer Continental Shelf (OCS) sources. Congress exempted Gulf of Mexico OCS sources west of 87.5 degrees longitude (near the border of Alabama and Florida) pending the results of a "three year" study conducted by the Department of Interior (DOI) - Minerals Management Service (MMS). The study required an examination of the impacts of emissions from OCS activities in such areas that fail to meet the National Ambient Air Quality Standard (NAAQS) for either ozone or nitrogen dioxide. This paper reviews the MMS Gulf of Mexico Air Quality Study's (GMAQS) emission inventory development, historical ozone episode modeling, field sampling, and preliminary photochemical modeling results. Industry has developed a standardized spreadsheet to calculate emissions and a software package to allow operators to figure out the cost to control OCS sources for NOx and VOCs under the EPA's OCS Air Regulations (40 CFR Part 55). Cost estimates are provided for various regulatory scenarios currently being reviewed by the EPA and MMS. Congressional Mandate Oil and gas exploration and production operations conducted on the OCS are regulated by the MMS, U.S. Coast Guard (USCG), Environmental Protection Agency (EPA), and the Department of Transportation (DOT). Air emission from OCS sources have historically been regulated by MMS until passage of the Clean Air Act Amendments of 1990 (CAAA). Title III, Section 328 of the CAAA - Air Pollution from OCS Activities (42 U.S.C. 7627), mandated that EPA develop regulations to control air pollution from OCS sources located offshore the States along the Pacific, Arctic and Atlantic Coasts, and along the United States Gulf Coast off the State of Florida eastward of longitude 87 degrees and 30 minutes. These regulations have been codified at 40 CFR Part 55 - Outer Continental Shelf Air Regulations. For portions of the United States Gulf Coast OCS that are adjacent to the States of Texas, Louisiana, Mississippi, and Alabama, 40 CFR Part 55 does not apply and air pollution regulatory authority remains with MMS. This congressional exemption, for the central and western Gulf of Mexico, from EPA OCS air regulations was passed pending a MMS research study which will examine the impacts of emissions from OCS activities in such areas that fail to meet the NAAQS for either ozone (O3) or nitrogen dioxide (NOx). Since Los Angeles, California is the only NOx non-attainment area in the United States the GMAQS will focus on O3 non-attainment areas along the Gulf Coast. The primary and secondary standard for O3 is 0.120 parts per million (ppm) (or 120 parts per billion (ppb)). An area is designated as non-attainment when one maximum hourly average O3 concentration is above 120 ppb. For the GMAQS these areas include Houston, Texas and their surrounding counties; Beaumont - Port Arthur, Texas; Baton Rouge and Lake Charles, Louisiana, with their surrounding parishes. GMAQS Objectives Section 328 language does not elaborate on how the GMAQS should be completed, only that it must be completed within three years of the CAAA becoming law. The CAAA became law on November 15, 1990. Given this congressional mandate, MMS issued a Request for Proposal (RFP) in May, 1991. Project objectives were to "…collect meteorological, air quality, and emissions data, and apply meteorological and photochemical models to determine impacts from existing and future outer continental shelf (OCS) oil and gas development in the Gulf of Mexico on adjacent non-attainment areas for ozone." DOI, MMS's parent organization, budgeted $5.5 million for the study. To aid the MMS in designing the GMAQS, the American Petroleum Institute's (API) Air Modeling Task Force commissioned a study entitled Preliminary Scope for a Gulf Coast Ozone Study. Similar modeling studies performed in southern and central California and the Lake Michigan region led to the conclusion that it would cost $24 million for a full-scale study that would take at least five years. This lack of adequate federal funding and time allotted limited the scope of the GMAQS. GMAQS Techinal Approach A contract for the GMAQS was awarded in the second quarter of 1992, almost two years after the CAAA became law, leaving one year to meet the congressional deadline. To meet the objectives of the GMAQS the following supporting objectives were determined:–development of emissions inventories;–identification of historical O3 episodes;–collection of meteorological and air quality data in the 1993 summer field sampling portion of the GMAQS;–application of a photochemical model and analysis of measured and model output to assess the effects of OCS activity on onshore O3 non-attainment areas;–characterization of uncertainty in model outputs; and–evaluation of the needs for future research. GMAQS Emission Inventory Development A critical component of the GMAQS is the development of a comprehensive emission inventory for photochemical grid modeling. This inventory includes offshore and onshore emissions from anthropogenic and biogenic sources. Of particular importance to the offshore industry are anthropogenic sources on oil and gas exploration and production facilities, crew and supply boats, helicopters, and pipelaying vessels.
Steam reformer tubes must withstand high temperature and pressures during operation and are made from centrifugally cast materials, typically HK‐40, HP modified, and microalloy materials. As operating conditions can result in various forms of damage, the identification and quantification of damage is of vital importance if tube life is to be predicted accurately. This article describes the recent developments in an inspection system, which uses multiple nondestructive testing techniques to provide the most comprehensive assessment of current tube condition. This is coupled with a sophisticated remaining life assessment software model, which not only predicts the remaining life of each tube in a furnace but can also calculate the effect of changes in future operating conditions on tube ageing. Field experiences and findings are also discussed in the article. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2010
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.