Deepwater Environmental Concerns

Of the potential environmental effects resulting from offshore oil and gas activities, impacts on marine mammals are a concern from an ecological viewpoint and because of unique legal status. Many species of whales, dolphins, and seals have been exploited by man for centuries, some to the brink of extinction (a few to extinction). In U.S. waters, all marine mammals are legally protected from exploitation under the Marine Mammal Protection Act (MMPA), and many of the large whales are also protected under the Endangered Species Act (ESA). Marine mammals and habitats are also part of environmental analyses conducted under the National Environmental Policy Act (NEPA). Historically, “effects” of offshore oil and gas operations on the environment were predominantly associated with water quality and chemical pollutants (oil spills, in particular); other concerns were drilling discharges and other potential chemical releases and platform runoff. In addition to contamination and toxic effects on marine mammals, other potential effects from offshore operations were recognized. For marine mammals, loss of hearing or masked communications can ultimately lead to dire consequences. Noise contamination—the effects of loud and/or disturbing sounds—was a particular concern in Alaska and west coast waters because of special circumstances. They included possible disruption of migratory routes of gray whales and bowhead whales and interference in native whale hunts. Minerals Management Service (MMS) funded several pioneering studies on the effects of noise on marine mammals and, with the Office of Naval Research, supported publication of the landmark book Marine Mammals and Noise in 1995. More recently, a 1995 3-D seismic survey in the Santa Barbara Channel brought Exxon, MMS, the National Marine Fisheries Service (NMFS), several state and local agencies, fishermen, and environmental groups to an impasse over survey procedures and mitigation. Issues were resolved only after several last-minute meetings. MMS's Pacific OCS Region met …

Summary This paper reviews the uses of production treating chemicals, gas processingchemicals, and stimulation and workover chemicals in U.S. offshore oil and gasproduction operations. The purpose, solubility properties, primary genericchemical types, purpose, solubility properties, primary generic chemical types, treatment methods, and typical use concentrations of each chemical group arediscussed. Acute aquatic toxicity data and solubility information arepresented. Introduction The objective of this paper is to examine briefly the broad range ofchemicals used in offshore oil and gas production in the U.S., primarily in the Gulf of Mexico. An important part of this primarily in the Gulf of Mexico. Animportant part of this examination is a presentation of data on acute aquatictoxicity of those chemical constituents that are likely to distribute intoproduced water discharged to the ocean. Most of these aquatic produced waterdischarged to the ocean. Most of these aquatic toxicity data have beendeveloped by chemical suppliers and have not been published previously in thetechnical literature. Evaluation of environmental impact involves factors otherthan the nature and concentration of chemicals added in production operationsand is beyond the scope of the paper. Most of the information and practicespresented are from interviews with technical specialists practices presentedare from interviews with technical specialists from four operating companiesand five chemical suppliers. Considerable attention continues to be focused onthe effects of offshore oil and gas producing operations on the marineenvironment, including the discharge of produced water into the ocean. Removalof produced oil from water has long been recognized as an essential step withstrict standards having been established by the U.S. Environmental Protection Agency (EPA). Present EPA permits do not limit treating chemicals in theproduced water permits do not limit treating chemicals in the produced waterdischarges. Governmental agencies in other areas of the world (e.g., North Sea, Baltic Sea, Mediterranean Sea) are considering preapproval of chemicals thatcould be present in produced-water preapproval of chemicals that could bepresent in produced-water discharges. Constituents of produced water have beenevaluated previously. Middleditch addressed the potential environmental impactof many of the constituents in the produced water. Other studies have focusedon biocides. The effects of various production treating chemicals added toproduced fluids were presented in a report prepared in 1985 for the Offshore Operators Committee (OOC) and prepared in 1985 for the Offshore Operators Committee (OOC) and submitted to the EPA. Investigators in other areas of theworld have shown interest in the environmental aspects of produced waterdischarged to the ocean. The American Petroleum Inst. (API) recently sponsoredan update of the 1985 OOC report, which was expanded to include the broad rangeof chemicals used in offshore oil and gas operations in the U.S. This paper isa condensation of selected portions of that report. Table 1 provides a conciseoverview of the U.S. offshore oil and gas industry. All these numbers wereconsidered preliminary by the sources, subject to revision. The waterproduction data probably have the greatest uncertainty. However, these data areprobably have the greatest uncertainty. However, these data are sufficientlyaccurate to give a good perspective of the industry. It is apparent that a veryhigh percentage of U.S. offshore activity is in the Gulf of Mexico, partialjustification for the emphasis on that area in this paper. Chemicals that maybe used in routine offshore producing operations in the U.S. are included inthe scope of this paper. For purposes of discussion, these chemicals have beenarbitrarily placed into three groups. placed into three groups.The production treating chemicals are those routinely added to the produced fluidsor to seawater or other source water that is injected for waterflooding. Thesechemicals are added for various purposes (such as corrosion or scaleinhibition).The gas processing chemicals are those used for freeze-pointdepression of gas hydrates or for dehydration of produced gas. Hydrogen sulfideand carbon dioxide normally are not produced gas. Hydrogen sulfide and carbondioxide normally are not removed from gas offshore and these sweeteningchemicals and processes are not covered in this paper. processes are notcovered in this paper.The group consists of the stimulation and workoverchemicals, particularly the acids and dense brines, along with their associatedadditives. These groups are discussed more fully later. Production Treating Chemicals Production Treating Chemicals The productiontreating chemicals include biocides, scale and corrosion inhibitors, emulsionbreakers (normal and reverse), coagulants, flocculants, antifoam, surfactants, and paraffin control chemicals. The types and quantities of chemicals used areminimized for both technical and economic reasons. None of the operatingcompanies used all these types of chemicals. JPT P. 604

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 18322, "MODU Performance in Hurricane Ivan," by B.P.M. Sharples, SPE, Offshore Risk & Technology Consulting Inc., and S. Buffington, U.S. Minerals Management Service, prepared for the 2006 Offshore Technology Conference, Houston, 1–4 May. Hurricane Ivan tracked through a high-density corridor of mobile offshore drilling units (MODUs) in the U.S. Gulf of Mexico (GOM), resulting in five semisubmersibles losing station and collapse of one jackup. In the aftermath of this hurricane, the industry is reflecting on lessons learned and re-examining industry standards. There was no loss of life and no major pollution from MODUs in Hurricane Ivan. A study commissioned by the U.S. Minerals Management Service (MMS) has chronicled the incidents of Hurricane Ivan to provide information that may lead to more-robust criteria for MODU safety. Introduction A study was commissioned by the MMS to gather information and examine MODU loss of station keeping during Hurricane Ivan. There were approximately 112 jackups and 32 semisubmersibles in the GOM at the time of Hurricane Ivan. Only three jackups were affected, and only one of those was a total loss. Five semisubmersibles were affected. Four left their general location and became adrift, and one moved approximately 3,000 ft. Most of the information came directly from drilling contractors, some came from oil companies, and some came from MMS files. Because the study was not complete at the time the full-length paper was written, the information is preliminary and subject to correction and change. Overview In September 2004, Hurricane Ivan, a Category 4 storm with waves exceeding the 100-year design criteria for offshore facilities, moved through the GOM. Of the more than 4,000 offshore oil and gas facilities and 33,000 miles of pipelines in federal waters, approximately 150 facilities and 10,000 miles of pipelines were in the direct path of Ivan. Damaged facilities included MODUs, offshore platforms, producing wells, topside systems, and pipeline systems that transport oil and gas ashore. MMS received industry reports indicating that seven platforms were destroyed, six platforms and five drilling rigs had major damage, and a substantial amount of oil and gas production remained shut-in because of pipeline damage. Semisubmersible MODUs Ocean Star and Ocean American. Diamond Offshore Drilling reported that drill platform Ocean Star drifted from its moored location. A visual inspection by fixed-wing aircraft confirmed that Ocean Star was afloat with no apparent damage. A visual inspection by aircraft of four other Diamond Offshore rigs operating in the path of Ivan also indicated no apparent dam-age or pollution. The Ocean Star was approximately 1.5 miles east of the storm track. Most of the wires were said to have broken below the rig fairlead near the highest loading point on the system. Hindcast weather data clearly show that conditions exceeded the American Petroleum Inst. (API) 10-year design criteria.

There has been an increase in oil spill research and development, especially after the Deepwater Horizon accident in the Gulf of Mexico. However, the public resources seem to be concentrated in the life sciences, rather than in engineering. The effect of oil on seaweeds and the effect of spilled oil on seabirds, for instance, seem to take precedence in government research funding, rather than engineering issues. If engineering preventive procedures and equipment are in place, then these adverse effects can be viewed as secondary. Offshore oil and gas production is an engineering endeavor, and it makes sense to expand resources in key aspects of engineering to allow for safer practices with regard to this endeavor. Offshore oil production is principally done by public companies, so it is logical that the government requires certain safety and operational standards with regard to permitting related offshore activities. It should follow that high governmental safety rules be set, and that production companies be aided by science and technology research that has been completed. A second thrust is to fund research and development for up-to-date science and engineering to meet the challenges of deep water drilling, especially in the area of machinery and devices that would help in mitigating accidents in deep water.

The use of chemicals in U.S. offshore oil and gas production operations are reviewed. The discussions cover the production treating chemicals, gas processing chemicals, and stimulation and workover chemicals. The purpose, solubility properties, primary generic chemical types, and typical use concentrations of each chemical group will be briefly discussed. Acute aquatic toxicity data and solubity information provided by the chemical suppliers are presented for 'the production treating chemicals, including biocides, scale and corrosion inhibitors, emulsion breakers, etc. Aquatic toxicity data for the gas processing chemicals (methanol glycoIs) were primarily obtained from the literature. A portion of these chemicals will dissolve in the produced water, with the remainder being distributed into the oil. Most of the water produced with oil and gas in offshore operations in the U.S. is treated to remove dispersed oil and grease, then discharged to the sea. The discussion on environmental aspects summarizes information on the aquatic toxicity, solubility, and typical treatment and discharge concentrations for chemicals used for each purpose. Actual environmental impact must include site specific factors, such as water depths, currents, temperature, etc., which are outside the scope of this paper. INTRODUCTION OBJECTIVE The objective of this paper is to examine briefly the broad range of chemicals used in offshore oil and gas production in the U.S. An important part of this examination will be a presentation of data on acute aquatic toxicity of those chemical constituents which are likely to distribute into produced water being discharged to the ocean. Most of this aquatic toxicity data has been developed by the chemical suppliers and has not been previously published in the technical literature. Evaluation of environmental impact involves factors other than the nature and concentration of chemicals added in production operations and is beyond the scope of the study. Most of the information and practices presented are based on the results of interviews with technical specialists with four operating companies and five chemical suppliers. BACKGROUND Considerable attention continues to be focused on the effects of offshore oil and gas producing operations on the marine environment. One aspect being examined is the discharge of produced water into the ocean. Removal of produced oil from water has long been recognized as an essential step with strict standards having been established by the Environmental Protection Agencyl,2,3. Present EPA permits do not limit treating chemicals in the produced water discharges. Governmental and intergovernmental agencies in other areas of the world (e.g. North Sea, Baltic Sea, Mediterranean Sea, etc.) are considering preapproval of chemicals that could be present in produced water discharges. Constituents of produced water have previously been evaluated. Middleditch4 addressed the potential environmental impact of many of the constituents in the produced water. Other studies have focused on bi0cides.5,6 The effect of various production treating chemicals added to produced fluids was presented in a report prepared in 1985 for the Offshore Operators Committee (OOC) and submitted to the EPA7 Investigators in other areas of the world have shown interest in the environmental aspects of produced water discharge to the oceans8. The American Petroleum Institute (API) recently sponsored an update of the 1985 OOC report, which was expanded to include the broad range of chemicals used in offshore oil and gas operations in the U.S.9,10. This paper is a condensation ofse

Careful attention must be given to identification, evaluation, and control of risks associated with development of mid-Atlantic offshore oil and gas if environmental damage and development delays are to be avoided. A number of approaches to safety, or risk management, are possible, but all seek to answer the central management, are possible, but all seek to answer the central management question, "Am I safe enough?" System safety methods are now available which can assist us in making intelligent decisions on safety measures to be incorporated in offshore development plans. Development of offshore oil and gas resources has brought new risks to exploratory and development drilling, production, and transportation operations. Concern over these risks has prompted a number of studies. After a brief review of these studies, the authors describe investigations in two areas: oil discharges in the Gulf of Mexico and worldwide accidents involving mobile offshore drilling units. A number of measures to reduce risks are being considered or have already been taken by government and industry. Greater application of system safety procedures offers new potential for reducing the risks in offshore development.

With the development of the petroleum industry, offshore oil and gas exploration and development are gradually shifting from shallow sea areas to deep sea areas, and the requirements for completion fluid density are also developing from low to high to ultra-high or even extra high. However, as the formation temperature and pressure increase, new challenges and difficulties in controlling completion fluid performance are faced. Therefore, there is an urgent need for a new type of high-performance completion fluid for deep water reservoirs, which is of great significance for ensuring the efficiency, safety and environmental protection of deep water completion operations. This paper starts from the existing problems and performance requirements of deep water high-density completion fluids, and provides a detailed introduction to the types and functions of additives required for completion fluids. It also systematically reviews and summarizes the different types of deep water high-density completion fluid systems that have emerged in recent years. High-density completion fluids face damage to the formation caused by solid phase completion fluids, while nonsolid phase completion fluids have problems such as high cost, strong corrosiveness and marine pollution. No completion fluids have been found that can simultaneously meet the multiple characteristics of high density, harmless reservoir, high-temperature resistance, environmental friendliness, nontoxicity and high economic benefits. To meet the performance requirements of deep water high-density completion fluids, the completion fluids will focus on improving adaptability in extreme environments, enhancing environmental performance and solving complex formation leakage problems. Through breakthroughs in key materials and technologies, innovation in environmentally friendly products, and the use of big data, cloud computing, artificial intelligence and other technologies to promote the development of intelligent completion fluids technologies is provided for the exploration and development of deep water and deep oil and gas resources.

The exploration and production of oil and gas in deep waters is very challenging and comes with high operational risks especially in offshore rigs and Floating Production Storage and Offloading (FPSO) facilities. The incidents associated with the operation of an FPSO could be catastrophic with ripple effects that involves socioeconomic, environmental, health and reputational damages as experienced in the British Petroleum Deepwater Horizon accident in the Gulf of Mexico in 2010, which has been described as one of the most catastrophic accident in the history of the oil and gas industry in the US, considering the huge lost recorded. Therefore, the purpose of this paper is to reveal how effective incident reporting can enhance risk reduction and accident prevention in offshore oil and gas facilities with emphasis on the FPSO facilities in the Nigerian Gulf of Guinea and beyond. Mix method of collection data was use, and qualitative and quantitative data were obtained through literature review; semi-structured interviews and online survey. The method of data analysis was Qualitative Analysis method where a Narrative Analysis was used to analyze data from online survey and semi-structured interviews and analysis carried out on how incident reporting can reduce risk and prevent accident. Emphasis is on the need for behavioral change and development of safety culture of unsafe act and unsafe condition reporting as a strategy to prevent accident occurrence was analyzed. This research succeeded in developing a template and a framework for incident reporting that can be adopted in any deep offshore oil and gas projects and operations, especially in FPSO operations, to enhance risk management, accident prevention, enhance operational sustainability and business profitability

The U.S. Minerals Management Service (MMS) for the first time has undertaken an assessment of undiscovered, conventionally recoverable petroleum resources that are not constrained by economic considerations. The new type of estimate is termed Undiscovered Resource Base (URB). It is calculated to realistically bracket the range of conventionally recoverable hydrocarbon volumes which probably remain to be discovered in the forseeable future on Federal Outer Continental Shelf (OCS) lands. The URB estimate is designed to be a geologic baseline assessment. It can be used to model a variety of unconventional recovery scenarios based on speculations as to future enhanced production technologies. INTRODUCTION Estimates of economically recoverable hydrocarbons, such as those previously published in Environmental Impact Statements, represent our hydrocarbon resource endowment with noncommercial hydrocarbon volumes removed from the totals. These types of estimates are appropriate in assessing areas proposed for leasing. They model economic constraints and incentives that would affect whether resources will be developed and produced as a result of Federal leasing of OCS lands. Rapid changes in petroleum prices and production costs has emphasized the desirability of another category of estimates for long-term planning purposes. As a result, MMS has expanded its assessment of undiscovered, economically recoverable hydrocarbon resources to include accumulations in smaller or deeper geologic traps in high-cost regimes that would not be economic at current prices. The methodology to derive this estimate is termed DIST, referring to distributions of possible field sizes. The estimate of the URB more adequately portrays the conventionally recoverable longer-term potential of high-cost frontier areas and economically inaccessible mature productive areas. DEFINITIONS The term URB is defined as an unconfirmed quantity of naturally occurring oil and gas estimated to exist in accordance with regional geologic analyses that would be conventionally recoverable from oil and gas fields larger than 1 million oil equivalent barrels (MMBOE) regardless of current accessibility or economics. Accumulations less than this level in size may be included in those cases where recovery is economically viable (nearshore, Gulf of Mexico (GOM) Region). Confirmation of the existence and quantity of this volume depends upon the results of future drilling of prospects and plays modeled by the PRESTO computer-based model. The URB definition is modified from one use1 by the National Petroleum Council in their assessment of Arctic resources. An assessment of the URB is responsive to recommendations 0f the National Academy of Sciences. DEVELOPMENT OF METHODOLOGY Currently available seismic and well log information, in conjunction with analog studies, provide sufficient control to adequately catalog large prospects for the PRESTO play inventory. The inventory is primarily a free byproduct from mapping eventually used in bid adequacy determination after a lease sale. Gaps in the inventory appear at the lower end of possible prospect and play sizes where imposed mapping or economic constraints have deleted smaller prospects or geologic outcomes. A methodology was needed to expand the PRESTO inventory to model hydrocarbon resources from fields smaller than the range of minimum accumulation sizes of prospects in the inventory.

Offshore oil and gas exploration contributes to global energy supplies. Still, it also poses significant environmental challenges, particularly concerning its impact on onshore climate patterns. This paper reviews how offshore oil and gas activities contribute to alterations in coastal and onshore climates, examining both direct emissions and broader environmental effects. By analyzing case studies from different regions, such as the North Sea and the Gulf of Mexico, and exploring policy frameworks and mitigation strategies, this review provides an in-depth understanding of the implications of offshore exploration on climate and ecosystems. The paper concludes by highlighting the need for sustainable practices to minimize these impacts

This study examines the complexities of maritime boundary disputes in Southeast Asia, focusing on offshore oil and gas exploration. The analysis centres on the legal framework provided by the United Nations Convention on the Law of the Sea (UNCLOS), exploring how its principles are applied and contested in real-world scenarios. Case studies, such as the Ambalat block conflict between Indonesia and Malaysia and the Malaysia-Thailand Joint Development Area (JDA), highlight the interplay between international law, resource agreement and geopolitical tensions. This research contextualises the challenges faced in Southeast Asia by incorporating comparative insights from similar disputes in regions like the Arctic and the Gulf of Mexico. Beyond legal considerations, the study addresses the economic stakes of hydrocarbon exploration and the environmental impact of offshore activities, emphasising the need for sustainable and cooperative approaches. This interdisciplinary investigation aims to comprehensively understand the factors shaping maritime boundary disputes and propose pathways towards effective conflict resolution and resource governance.

The deepwater part of the Gulf of Mexico has shown a remarkable increase in oil and gas exploration, development, and production. In part, this is because of the development of new technologies reducing operational costs and risks, as well as the finding of reservoirs with high-production wells. With expanding development in deep water come increasing challenges in managing our nation’s Submerged Cultural Heritage on the Outer Continental Shelf and Slope. To fulfill obligations under Section 106 of the Historic Preservation Act of 1966 (36 CFR 800), managers need a clearer understanding of the size of debris fields expected around deepwater shipwrecks, as well as their state of preservation and future research potential—both cultural and biological. With this in mind, the Minerals Management Service, in partnership with the National Oceanographic Partnership Program and the National Oceanographic and Atmospheric Administration’s Office of Ocean Explorations, launched the Deep Gulf Wrecks Project.

An autonomous underwater robot for tracking and monitoring of subsea plumes after oil spills and gas leaks from seafloor

The study explores the feasibility of utilizing Ocean Thermal Energy Conversion (OTEC) systems collocated with deepwater oil and gas facilities to power monitoring activities for plugged and permanently abandoned (PA) offshore oil and gas wells in the Gulf of Mexico (GOM). As offshore oil and gas operations expand, the need for sustainable monitoring solutions for PA wells, which may release hydrocarbons, may become critical. Current regulations do not mandate long-term ongoing monitoring post-PA, presenting an opportunity for innovative approaches. This research evaluates the potential of OTEC, a renewable marine energy technology, to provide continuous, dispatchable power for such monitoring systems. The study models an OTEC system collocated with an oil and gas platform, assessing its capability to power long-range autonomous underwater vehicles (AUVs) shuttled to the relevant locations for periodic surveys of PA wells. The findings suggest that while OTEC can technically support PA well monitoring, logistical challenges such as and economic viability remain. The study underscores the need for further research and investment in OTEC technology to enhance its economic competitiveness and integration with offshore operations. This approach not only aids in addressing potential PA well hydrocarbon release concerns but also offers a model for other offshore monitoring applications, including subsea geologic carbon dioxide (CO2) storage projects.

ABSTRACT: X Oilfield is located in the southern Bohai Sea. The formation fractures of the Neogene Minghuazhen Formation are developed. During drilling, wellbore collapse and block falling are prone to occur, and even cause stuck and stuck drilling. This paper presents a comprehensive geomechanical method which combines theoretical analysis with numerical simulation. By collecting a large number of geological, seismic, drilling and logging data, this method selects the appropriate theoretical model to predict and calculate the ground stress, pore pressure, fracture pressure, collapse pressure and rock mechanical parameters of well A, and draws the formation four pressure profile, and then obtains the safe drilling fluid density window of the well. In this paper, based on the elastic-plastic mechanics theory, the stress state of the wall rock is analyzed, and the numerical simulation of wellbore stability is carried out by using ABAQUS software. The influence of pore pressure, formation strength and drilling fluid density on wellbore stability is analyzed, which provides a powerful tool for understanding the wellbore instability mechanism of the target block of X oilfield, and effectively controls the wellbore instability phenomenon of Well A. 1. INTRODUCTION Since the 21st century, China has gradually focused on offshore oil and gas development in the context of the gradual depletion of conventional oil resources on land. Overall, there are relatively abundant oil and gas deposits in Chinese offshore areas. China’s offshore oil and gas resources are abundant in general. In recent years, Bohai Basin has made significant oil and gas discoveries and has a good development prospect. It is the main offshore oil and gas production area in China . The target well in this paper is well A, which is located in the south of Bohai Sea. The core technology of offshore drilling and completion and the stability of borehole wall are the key issues for the smooth development of offshore oil and gas resources. The theory and research results involved in this paper can not only provide scientific guidance for well A, but also provide theoretical support for the well area of the oilfield and even for the drilling of Bohai Bay in China, which has very important engineering guiding significance.