Offshore Petroleum Production Research Articles

Tactical planning of offshore petroleum production

This paper describes a model for tactical planning of Norwegian petroleum production. The problem involves regulation of production levels from wells, splitting of production flows into oil and gas products, further processing of gas and transportation in a pipeline network. Blending and processing of gas is necessary to satisfy quality requirements in the markets. The problem is formulated with multi-component flows, regulation alternatives in production, non-linear splitting for chemical processing and linear quality constraints on composite products. Production and splitting are modelled with integer requirements. The model is implemented in Xpress MP with a Visual Basic supported user interface in Excel. It is constructed in cooperation with the major Norwegian oil company, Statoil and can identify optimal production patterns and assist in planning of possible shut-downs, demonstrate system robustness to customers and aid in contract negotiations.

Marine Pollution from the Offshore Oil and Gas Industry: Review of Major Conventions and Russian Law (Part I)

This article discusses provisions of major international and regional conventions that regulate marine pollution arising from offshore petroleum exploration and production, and examines the Russian environmental regime for offshore oil and gas operations. The article analyses existing federal environmental legislation in Russia, its application to the offshore petroleum industry, and the Russian administrative structure overseeing the ecological regime. The article also briefly discusses sources of marine pollution from offshore activities, and provides an overview of the Russian offshore industry and offshore hydrocarbon resources on the Russian continental shelf. The purpose of this article is to introduce readers to the legal framework for environmental and offshore petroleum regulation in Russia, determine whether Russian law adequately deals with pollution from offshore operations, and provide an update on the present position of international law on this issue. The international regime is discussed in Part I of the article and the Russian regulatory system will be examined in Part II.

Definition of an Offshore Petroleum Production System by Using Fuzzy Sets and Utility Functions

Field development is a very important task in the petroleum industry. Decisions in this area may lead either to profitable success or to expensive failures, and usually involve several distinct areas in the scope of Petroleum Engineering and Science, such as Geology, Petreoleum Engineering, Offshore Engineering and Economics. Therefore, these subjects must be well understood by teams supporting the decision-making process. This work proposes a methodology to support managers in one stage of field development: the definition of the field production system. In order to determinate the production system to be installed in an oil field, attributes such as investment, profitability, safety, environmental preservation and technological experience must be considered. A decision-making team or agent must weight these attributes in order to achieve solutions accordingly to the company strategies and objectives. Combining a few mathematical tools to represent the process, the methodology proposed herein is an approach that considers not only the financial variables involved in a field decision process, but might include other aspects, or attributes, also important to guide a decision. To this end, the application of Multi-Attribute Analysis concepts is suggested. Also, to support the decision-making agent, the approach follows Utility Functions concepts in order to numerically represent the agent trend or inclination to each option. Considering that subjectivity and imprecision are naturally involved in the decision-making process, the approach incorporates Fuzzy Sets Theory concepts as a means of formalizing the computation of this uncertainty.

Study of the paraffin deposit formation using the cold finger methodology for Brazilian crude oils

Transportation of paraffinic crude in a cold environment can result in wax depositions, which are solid deposits, on the pipe wall. The formation of paraffin in the bulk of the petroleum is a crystallization process in solution. Such phenomenon occurs along the pipe connected to offshore wells and even onshore. Its main implication is a paraffin blockage with serious economical consequences. This work aims to learn about paraffin deposit formation using a cold finger methodology, in two types of Brazilian crude oils (32 API and 20 API). The polythermal method is used in various experiments using different temperatures in both cold finger and bulk of the fluid. The experiments measure: the thickness of the deposits, as well as the deposition rates, degree of subcooling and, finally, the induction for the onset of wax. The methodology allows the evaluation of the critical time of deposition and the critical temperature difference between the hot petroleum source and the cold seawater temperature. It is shown that the deposit rate depends on this temperature difference, as well as the cooling surface, the nucleation kinetics and the growth of the crystals on the cold finger surface. The work discusses carefully the experiments design under the light of dimensional analysis. The values of critical temperature differences are relatively small and show that the encrustation is easily attained in the offshore petroleum flow. The methodology implemented is simple and allows the prediction of very important information about the mechanism of paraffin encrustation that could pave the way to avoid paraffin deposition in offshore petroleum production due to high temperature differences between the heat petroleum sink source and the cold seawater.

Galvanic Anode Cathodic Polarization of Steel in Seawater: Part III — Retrofit Cathodic Protection of Offshore Structures

Abstract Numerous offshore petroleum production structures have aged to the point that the galvanic anodes on these will expire before the end of their useful lives. Retrofit of the cathodic protec...

IMPROVING THE OPERABILITY OF REMOTELY OPERATED VEHICLES

Underwater Remotely Operated Vehicles (ROV's) have a significant support role to play in offshore petroleum production facilities. The extent to which ROVs can replace diver-based operations depends significantly on ROV capacity and the relative costs of mobilising and implementing the two modes of underwater operation. This paper presents work directed at two aspects of ROV operability: the quality of visual information presented to the ROV pilots and the degree of station keeping control exhibited by the vehicle.Significant improvement in pilot performance of selected maintenance-type tasks has been achieved by the use of a purpose built underwater stereoscopic video camera and associated ship-based stereoscopic display unit. Two generations of cameras have now been built and used on a Perry Triton vehicle in use at the North Rankin A platform on the North West Shelf.In a related program, stereoscopic images of the platform structure are processed to determine the relative position of the ROV. Changes in position are used as inputs to thruster control algorithms, with a view to enabling the vehicle to hold position in fluctuating current fields. The position data from the processed 3D images are linked to output from an on-board inertial system to enable position to be maintained despite periodic loss of visual information.First trials of the combined vision-inertial system indicated some success, notably using the vision system, but indicated difficulties with the inertial package and its integration into the control process. An extension of this project is now being supported by the Australian Maritime Engineering Cooperative Research Centre (AMECRC).

Colloid chemistry and modern instrumentation in offshore petroleum production and transport

A summary of the central problems of a colloidal chemical nature in offshore crude oil production and transport is presented. It is concluded that emulsified systems, mainly water/oil, are of high importance. Under North Sea conditions these emulsions will become increasingly important with the ageing of fields in production and with the exploitation of new marginal fields. Spectroscopic techniques applied to characterize emulsified systems are also presented.

Biodegradation of Alkylnaphthalenes in Sediments Adjacent to an Off-Shore Petroleum Production Platform

Abstract Sediments adjacent to an off-shore petroleum production platform in North Western Australia contain kerosene-like hydrocarbons from oil-based drilling mud. The hydrocarbons in these sediments were examined by gas chromatography-mass spectrometry (GC-MS) and direct deposition gas chromatography-Fourier transform infrared spectroscopy (GC-FTIR). As distance from the platform increased, the hydrocarbons exhibited an increasingly biodegraded signature. The relative susceptibility to biodegradation for the individual dimethylnaphthalene (DMN), trimethylnaphthalene (TMN) and tetramethylnaphthalene (TeMN) isomers present in the samples were determined using GC-MS and GC-FTIR as complementary analytical techniques.

Economic impacts of energy development

This article examines the economic impacts of offshore petroleum extraction and production on communities in Louisiana. The study extends previous work concerning the economic impacts of energy development by including all phases of petroleum development, by accounting for the degree and type of involvement of the community in petroleum production, by using analysis of variance to determine the effect of the rate and direction of change in as well as level of petroleum activity, and by using time series regression to examine the effect of year‐to‐year changes in activity on year‐to‐year changes in economic impacts. The findings show an initial improvement in economic conditions followed by serious economic decline. The results also point out the need for a diversified involvement in petroleum production and the necessity of mitigation programs during the boom and decline in petroleum activity.

Thermogenic hydrocarbons in seawater of the Gippsland Shelf, southeast Australia

An offshore survey measured the concentration of thermogenic hydrocarbons (THCs) in samples extracted from seawater at 718 locations along 22 traverse lines across the Gippsland Shelf, southeast Australia, and recorded compounds typical of subsurface crude oil and natural gas (petroleum) accumulations. Background concentrations of 8 ppm, with isolated peak levels of 20 to 52 ppm, were detected in samples extracted from seawater at depths of 30 to 50 m over distances of 10 km. Two sources have been suggested - seepage of THCs from subsurface accumulations of petroleum, or THCs in waste-water discharged by several offshore petroleum production facilities which are present on the shelf. A waste-water source is favoured because of the transitory nature of the concentrations, and changes in composition consistent with plume drift away from the point(s) of discharge. Overall, however, the concentration of THCs in waters of the Gippsland Shelf compare favourably with levels in waters affected by urban runoff. The concentration of THCs in other coastal waters from urban and onshore sources is low, equivalent to the background concentration in the major oceans of the world.

Marine environments of Southeast Australia (Gippsland Shelf and Bass Strait) and the impact of offshore petroleum exploration and production activity

Marine environments of the Gippsland Shelf (Gippsland Basin) and Bass Strait (Bass Basin) are described and an exploratory (preliminary) assessment of the potential effects of petroleum exploration and production activity are outlined. Exploration activity has been undertaken in both areas and inferred environmental impacts are typically short term. Production activities are restricted to the Gippsland Basin, have potential for long‐term impact, and are likely to result in trace levels of hydrocarbons being present within 1 km of the point(s) of discharge of drilling waste or wastewater. The inferred impact of produced wastewater, which may contain up to a maximum of 30 ppm of produced hydrocarbons, on waters of the Gippsland Shelf is presently being modeled and quantified. Results indicate that the background level of produced petroleum in waters of the Gippsland Shelf is less than in areas around Sydney and Melbourne affected by urban runoff. Potential strategies for monitoring environmental quality on the Gippsland Shelf include a biologically based “mussel watch” program.

Air medical transport of patients from offshore oil and gas facilities: Historical Accident Data and Initial Experience

The offshore petroleum exploration and production industry (OSI) is isolated from traditional means of access to emergent health care and may benefit from the unique attributes of helicopter air medical transport. This study was undertaken to review the incidence of OSI-related incidents, injuries and deaths, and report the initial experience of a civilian hospital-based helicopter air transport program in the evacuation of offshore patients. It was learned that the mean annual incidence of major OSI accidents from 1980 to 1986 was 19.1 (+/- 7.0). Mean annual mortality and reported injury were 14.7 (+/- 7.6) and 36.7 (+/- 25.4) patients respectively. Fires and explosions were the most frequently reported events at 62 per year (+/- 11.5/year). Nine OSI patients were evacuated by helicopter during the study's eight-month pilot period (seven for trauma and two for medical illness). One of the nine patients had been exposed to a potentially hazardous substance, requiring changes in the air medical team's operations, aircraft and equipment. The study shows that the offshore petroleum environment is ideally suited for air medical transport, as injuries are common and medical illnesses are to be expected. However, air medical programs operating offshore must deal with additional regulatory requirements and develop operational procedures to ensure safety during these flights.

Supervision System Design for a Petroleum Production Application

Abstract The contents of this paper arc the result of a joint project involving the Centre d’Automalique de Lille (Advanced Control Research Centre, Lille) and ELF Aquitaine. The study presented concerns the design of a supervision system (Fault Detection and Diagnosis) within the framework of the P LA TINE project (PLATeforme INhabiteE or unmanned platform): an offshore petroleum production platform without an operator permanently present on the site. Remote operation of these unmanned platforms uses only data from the sensors for the control, maintenance and safety functions. Consequently the detection, diagnosis and isolation of failures of these sensors must be prepared and planned for before building up the base of validated data which will supply the various users with more reliable information on the system. After presenting a practical application representative of the problems to be dealt with (a gas dehydration unit), the method, which uses analytical redundancy and structural analysis applied to this real case, is described. The results obtained on this project show the usefulness of analytical redundancy in the validation of data from the sensors. The method used to achieve this allows the diagnostic capacities of the instrumentation to be characterised during the design phase. Tests have shown the feasibility of this approach.

Petroleum Drilling and Production Operations in the Gulf of Mexico

Decades of offshore and inland petroleum drilling and production in the Gulf of Mexico and on the Gulf coast have provided the much needed energy and chemical feedstocks to the nation, and also have made an impact on the environment in the area. Our study showed deposits of contaminated sediment on the ocean floor around offshore platforms, old reserve pits, and dump sites next to many surface facilities and compressor stations. The substances found on the ocean floor and in dump sites are simple or emulsified mixtures of silt, hydrocarbons, and water. The cleaning of the ocean floor and pits is an economic and technical challenge. Hydrocarbons are from crude oil and chemical additions for various operational necessities, including additions of biocides, corrosion inhibitors, antifreezes, and coagulants. When the new government regulations lower the allowable maximum total organic carbon level to the 50 ppm range, these hydrocarbons can no longer be ignored by drilling and production operators.

The effects of man-made noise on the behavior of marine animals

Reports of the effects of man-made noise on the behavior and related processes of marine animals are widely scattered among a variety of literature sources. This report brings much of this literature together and attempts a synthesis by a comparative analysis of the results obtained from taxonomically diverse species. Mammals and fishes are emphasized since little is known about the subject in other groups. Field studies have shown aversion by various baleen and toothed whales to the noise accompanying offshore petroleum exploration and production. Variation in response involves: level of source-noise to that of the ambient, degree of naivete of the animals to the source-noise, on-going activity at the time of exposure and, to an uncertain degree, the species involved. Although seals and their relatives have not been adequately examined regarding their response to underwater noise, individuals have been shown to be clearly susceptible (anatomically based) to high levels of such noise. Studies have also shown the deleterious effects of even moderate noise levels on hearing in fishes. Aversion to various types of man-made noise has been noted several times, with associated levels being similar to those noted when similar responses were recorded by whales. Finally, several studies have documented abnormal growth and reproductive processes in several species of fin- and shellfish due to high levels of man-made noise. Such findings should be of concern to the field of aquaculture, since it is dependent on such fundamental processes.

Ram-Verification Study and Testing of an Integrated Process Control and Safety System

This paper presents results from several studies performed to verify the functionality and integrity of a safety system applied in offshore petroleum production. The results reported are a short summary of several studies performed by SINTEF (The Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology). Configurations are presented, together with the strategy implemented to test support equipment and the primary functions of the system.The major weak points identified during the studies are described, together with recommended corrective actions. The experience gained during these studies is of general value, and applicable also to other hardware configurations.Also the estimated failure rates for the safety system are presented. Overall fail to function as well as trip rates are presented, including the contribution from the various units to the total figures.Findings from a separate study concentrating on testing of the special reliable unit are presented. This study was performed together with the vendor, to reduce errors and eliminate weak points, also including software errors, prior to commissioning.

Long March II

Introduction In October, 1934, Mao Tse-Tung led his armies on a 6,000-mile march across China. This gruelling one-year trek known as "The Long March" crossed 18mountain ranges and 24 rivers and was one of the heroic events in China'smodern history that culminated in her liberation on October 1, 1949. Another trek is now taking place in China - Long March II - the arduousjourney to industrial growth and economic prosperity. And, leadinginternational corporations and businessmen are joining in on Long March II. China is surviving the current world recession well. Where other countriesare foundering under enormous debt loads, China remains virtually debt free.Intensely competitive foreign suppliers of goods and services are beating apath to her doors thus ensuring a huge storehouse of products at bargainprices. "China is a tough market" say both experienced and novice China watchers andtraders. And yet, the hotels of Beijing (Peking) are crammed with businessmen, year round, all hoping to close deals with this stirring giant. Think of onebillion people in an area slightly smaller than Canada, all eager for theimplementation of policies to improve their standard of living. The growingawareness and demands of one-quarter of the world's population for food, shelter and consumer goods is staggering. Directly related to the desire for an improved standard of living is thedemand for energy and China's ability to develop her energy resources in stepwith this growing demand. Over the next 20 years, a World Bank study estimates China will spend $420 to $480 billion to develop its energy infrastructureincluding offshore petroleum exploration and production, onshore enhancedrecovery, oil and gas pipelines, coal mining facilities and hydro-electric andnuclear power stations.

Height-Period Joint Probabilities in Hurricane Camille

An ocean data gathering program in the Gulf of Mexico obtained continuous wave records from six offshore petroleum production platforms during the passage of several hurricanes and tropical storms. This note describes the joint probability of wave heights and periods as hurricane Camille (August 1969, one of the most severe hurricanes on record) approached and passed near one of the six platforms. This analysis was motivated by a need to estimate probabilities of wave height and period combinations which produce bottom pressures capable of triggering submarine mudslides off the Mississippi River delta. The observed joint probabilities are compared to a frequently used joint distribution. The results presented are useful for calculating other probabilities which are functions of hurricane wave height and period. Applications include determination of differential bottom pressures between wave crests and troughs capable of triggering submarine slumping on continental shelves, calculation of drag and inertial forces exerted on structures, and estimation of vessel motion in high seas.

Update-Outer Continental Shelf Lease Management Program

To avoid stealing this author's thunder, let us paraphrase, though inadequately, his closing quotation. There is nothing that stands alone; there is nothing that only stands; and the piper will be paid. Introduction The evolution of the petroleum industry and the concurrent emergence of conservation laws and regulations over the past 50 years have been of great significance. From the highly individualistic oil producers of a few decades ago have emerged a major industry and a major technology. Now it is comprehensively and constructively regulated so as to permit efficient exploration and the development and recovery of the nation's oil and gas reserves, while protecting the environment and the rights of others. In retrospect, the early oil man by today's standards seems wasteful, but it must be remembered that knowledge of the causes of waste and the remedies for it was meager. Despite its relatively short life span, the petroleum industry has a remarkable record of rapid development of technology and its widespread use. Government has the responsibility to establish reasonable regulations and standards that assure, safe, clean operations, while also giving proper consideration to technical feasibility and lead times. The burden of proving that petroleum operations can be carried on safely rests mainly with the petroleum industry. Government and industry have a joint responsibility to avoid improperly conducted Outer Continental Shelf (OCS) operations; they must also avoid the misunderstanding of those operations that causes the public consent to be withheld. The public needs to know that a satisfactory technologic capability exists for safely carrying out difficult and potentially dangerous operations, and it needs to be assured that adequate regulatory and supervisory capabilities exist to see that operations will indeed be conducted safely. Each operator must have that earnest desire to conduct his activities properly that often is more effective than regulations or enforcement procedures. Nevertheless, considering the important values at stake, the protection of the public interest should not depend on good intentions alone. The U. S. Geological Survey (USGS) is the organization that bears the responsibility for seeing that offshore petroleum exploration and production are conducted properly. Oil spills occur because of either human error or faulty technology. When human error is involved, the number of accidents is somewhat related to the number of people involved and to the complexity of the system. Accidents, and in particular oil spills, also result from improper design of equipment or because of its deterioration. Two general questions are to be dealt with. The first is, How are accidents to be kept to a minimum? This requires foreseeing hazards and taking preventive measures. The second is, How do we take care of accidents that happen despite the best preventive efforts? Precautionary measures, improved training of workers, improved organizational procedures, and advances in technology will reduce the number of accidents. The USGS is an important public source of unbiased information and judgments about the earth's physical resources and problems related to their use physical resources and problems related to their use and conservation. JPT P. 388

Sources, sinks, and concentrations of light hydrocarbons in the Gulf of Mexico

A survey of the concentrations of light hydrocarbons in the Gulf of Mexico has been made aboard the R.V. Alaminos of Texas A&M University. The hydrocarbon analyzer consists of a modified Beckman process gas chromatograph with a flame ionization detector. For surface profiling, gases are ‘stripped’ from seawater taken 3 meters below the sea surface by vacuum extraction with a 12-stage booster pump. These gases are injected periodically into the gas stream of the chromatograph for analysis. The system also has the capability of analyzing discrete seawater samples either by the method of McAullife or by the method of Swinnerton and his co-workers. Coastal waters of the Gulf of Mexico are not in equilibrium with the atmosphere insofar as low molecular weight hydrocarbons are concerned, even though methane in most of the open Gulf of Mexico is in fairly close equilibrium with the atmosphere. The coastal waters of the gulf act both as a source and as a sink for atmospheric methane. The important man-derived sources of methane in the gulf are ports with their associated shipping and industrial activity, offshore petroleum drilling and production operations, and open ocean shipping activity. High light hydrocarbon concentrations have been found in the vicinity of a tanker discharging ‘clean ballast water.’ The important natural sources include seepage from oil and gas reservoirs and anaerobic production of methane. The main sink for atmospheric methane in the Gulf of Mexico is in the Yucatan area, where there is major upwelling of deep water with low hydrocarbon concentrations.