Environmental Impact Assessment Follow-Up of Seismic Survey Offshore Activities in Brazil

Follow-up of environmental impacts is an integral part of the Environmental Impact Assessment (EIA) process, closely related to the effectiveness of the instrument. EIA follow-up has been receiving a lot of interest from scientists and practitioners, though it is recognized as one of the weakest points of EIA systems globally. Also, EIA follow-up is influenced by the context, mainly in terms of the types of projects or activities and their related impacts on the environment. Therefore, the present paper is focused on the investigation of the follow-up stage applied to the activity of seismic survey coupled with offshore oil & gas exploitation in Brazil. Research was based on a qualitative approach that included document analysis and semi-structured interviews with analysts involved in EIA processes, and sought to generate evidence of effectiveness of the EIA follow-up as conducted by the Federal Environment Agency (Ibama) in order to situate the practice of follow-up in the broader context of international best practice principles. Based on the findings, it was concluded that, due to the peculiarities of offshore seismic survey, it is necessary to promote adaptations in the procedures for monitoring impacts in order to ensure proper alignment with the principles and conceptual foundations that guide EIA practice. Specifically, the timing of the execution of the activity imposes challenges for its integration into the “conventional” cycle that has guided the monitoring of the impacts in the EIA of projects.

Multistring analysis of wellhead movement and uncemented casing strength in offshore oil and gas wells

This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include operating load during drilling and completion and the temperature field,pressure field and the end effect of pressure during gas production.The finite element method for multistring analysis is developed to simulate random contact between casings.The relevant finite element analysis scheme is also presented according to the actual procedures of drilling,completion and gas production.Finally,field cases are presented and analyzed using the proposed methods.These are four offshore wells in the South China Sea.The calculated wellhead growths during gas production are compared with measured values.The results show that the wellhead subsides during drilling and completion and grows up during gas production.The theoretical and finite element solutions for wellhead growth are in good agreement with measured values and the deviations of calculation are within 10％.The maximum von Mises stress on the uncemented intermediate casing occurs during the running of the oil tube.The maximum von Mises stress on the uncemented production casing,calculated with the theoretical method occurs at removing the blow-out-preventer （BOP） while that calculated with the finite element method occurs at gas production.Finite element solutions for von Mises stress are recommended and the uncemented casings of four wells satisfy strength requirements.

MECHANICAL PROPERTIES OF LONGITUDINAL SUBMERGED ARC WELDED STEEL PIPES USED FOR GAS PIPELINE OF OFFSHORE OIL

Since the development of offshore oil and gas, increased submarine oil and gas pipelines were installed. All the early steel pipes of submarine pipelines depended on importing because of the strict requirements of comprehensive properties, such as, anti-corrosion, resistance to pressure and so on. To research and develop domes- tic steel pipes used for the submarine pipeline, the Longitudinal-seam Submerged Arc Welded （LSAW） pipes were made of steel plates cut from leveled hot rolled coils by both the JCOE and UOE （the forming process in which the plate like the letter “J”, “C”, “0” or “U” shape, then expansion） forming processes. Furthermore, the mechanical properties of the pipe base metal and weld metal were tested, and the results were in accordance with the corresponding pipe specification API SPEC 5L or DNV- OS-FI01, which showed that domestic LSAW pipes could be used for submarine oil and gas pipelines.

Exploration prospects of oil and gas in the Northwestern part of the Offshore Indus Basin, Pakistan

Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.

Opportunities and Challenges of Robotics and Automation in Offshore Oil &Gas Industry

The oil and gas industry will continue to boom in the coming few decades. Obtaining oil and gas from conventional and non-conventional resources will become more and more challenging. This intensifying need will impose very considerable demands on work force, financial and technology capabilities. Since the future supplies of oil and gas are to expand, advanced technology will become increasingly necessary to obtain access to more challenging conventional and non-conventional resources. Therefore oil and gas technologies will be very costly to operate in the coming future due to hostile, hard-to-reach environments. The offshore oil industry will become a complicated myriad of advanced equipment, structures, and work force. Our objectives are to identify potential applications and research directions of robotics and automation in the oil & gas field and explore the obstacles and challenges of robotic and automation applications to this area. This study performs the necessary survey and investigation about the work conditions of robotics and automation equipment in the oil and gas industry, especially offshore oil rigs. The oil & gas industry processes are first investigated. The personals and tasks are then explored. Furthermore, this paper reviews the current robotic automation technology. The challenges and requirements are identified for robotics and automation equipment in the oil and gas industry. The requirements of robotics and automation in the oil & gas industry are presented. Future research opportunities are discussed from a technical perspective.

International Law on Liability and Compensation in the Offshore Oil ＆ Gas Industry

Offshore oil and gas exploration and production comes with risk of release of hydrocarbons in to sea. Today, the probability of such an event is relatively low, but the consequences are nevertheless significant and can cover a vast geographical area. As such, it raises the question as to whether liability and compensation in oil ＆ gas related incidents should be covered under international law. Current international legislation addresses the issue mainly in terms of shipping. This paper attempts to shed light on the topic in relation to oil and gas exploration whilst investigating notable events in the UK and the USA. The findings show that domestic laws of these countries cover the matter sufficiently. However, the question of whether the regulation should fall under international regulation can unfortunately not be answered with confidence as it would require a test-case of a situation where an oil spill affects multiple littoral states.

China Offshore Oil Industry and Foreign Investment

The history of China's offshore oil industry can be traced back to late 1950's when geophysical surveys started in limited offshore areas.Then,in 1960's and 1970's,a few exploratory wells scattered from north down to south were drilled resulting in a number of discoveries with the total proven oil in place being merely 40 million tons.In fact,the China's offshore oil industry in a real sence did not emerge on the horizon until early 1980's when China opened its door to outside world and the China National Offshore Oil Corporation(CNOOC)was born.

Condition Assessment Techniques for Aged Fixed-Type Offshore Platforms Considering Decommissioning:a Historical Review

In this study,the technical papers on structural condition assessment of aged fixed-type offshore platforms reported over the past few decades are presented.Other ancillary related works are also discussed.Large numbers of researches are available in the area of requalification for life extension of offshore jacket platforms.Many of these studies involve reassessment of existing platforms by means of conducting pushover analysis,a static nonlinear collapse analysis method to evaluate the structure nonlinear behaviour and capacity beyond the elastic limit.From here,the failure mechanism and inherent reserve strength/capacity of the overall truss structure are determined.This method of doing reassessment is described clearly in the industry-adopted codes and standards such the API,ISO,PTS and NORSOK codes.This may help understand the structural behaviour of aged fixed offshore jacket structures for maintenance or decommissioning.

Assessment of Safety Culture in Global Offshore Environments

This project aims at presenting detailed assessment of health and safety culture in global offshore environments. Such assessment will be then utilized for developing and recommending a model capable of integrating safety behaviour and culture in global offshore environments. The global offshore environment is a quite wider term and therefore underlying study has specified and narrowed it down to the oil and gas industry. In other words, the discussion of health and safety culture is done in light of oil and gas industry and its environment. The proposed model “incident-free and low-risk contracting model” aims at fostering health and safety culture in oil and gas environments. It is worth mentioning that implementation of model requires effective support and collaboration between trade unions, industry associations, employers, and government agencies. The objectives of the proposed model will be identified in terms of Fostering sound leadership, Gaining management commitment, Gaining support and involvement of workforce, Reducing risk instances, Accident reduction objective.

Strategic Thinking on Shallow-water Oil and Gas Exploration in Offshore China

The oil and gas exploration in offshore China has made great achievements,and as the important areas of offshore exploration,the shallow waters contribute most of the oil and gas reserves and production.However,the available area for exploration is diminishing and the cost of exploration is rising.The field changes and ever increasing difficulties of exploration bring new challenges technically and economically.Therefore,for effective exploration of shallow-water oil and gas in offshore China,it is necessary to center on the general requirements of becoming a powerful marine country and the ideas of value exploration,initiate key research projects in the fields of China's offshore stratigraphic-lithologic reserves,Paleogene reserves,buried-hill reserves,high temperature and pressure reserves and hydrocarbon-rich sags,and form geological theories and explorative technologies of large and medium size oil and gas field in offshore China.The measures regarding the challenges include:(1) Innovating theoretical understanding and optimizing new exploration fields,(2) developing technical capabilities and improving the success rate of exploration,and(3) enhancing management level and deepening value exploration.

All-Electric Subsea Control Systems and the Effects on Subsea Manifold Valves

Subsea development is moving constantly toward simplification,digitalization,and cost-out strategies because the exploration and production of hydrocarbons are moving toward deeper and remote sea water areas.Usage of all-electric subsea technology instead of hydraulic technology is growing and will be the future of subsea systems due to the former’s environmental and functional advantages and reduced costs.The benefits of all-electric subsea systems are health,safety,and environment(HSE)and improved reliability,flexibility,and functionality compared with traditional hydraulic-electrical systems.Existing electrohydraulic technology for a typical subsea system,hydraulic and electric actuators,and subsea manifold valves including valve types and selection philosophy have been reviewed in this paper.Some major worldwide oil companies such as Equinor and Schlumberger have successful experiences with subsea electric actuators.Considering the benefits of all-electric technology especially in terms of cost and HSE,as well as successful experiences of two major oil companies,further research in this area is warranted.One of the gaps in existing reviewed literature is the effect of using all-electric actuators for manifold valves.Thus,three main questions related to electric actuator selection,requirement of safety integrity level(SIL),and effect of using electric actuators on manifold valve selection have been addressed and answered.Forty hydraulic actuated manifold valves from nine past subsea projects in different parts of the world,mainly Africa and Australia,have been selected for the analysis of all-electric actuators.Results show that 93%of the valves require spring-return electric actuators,whereas 7%can be operated with conventional electric actuators without any spring.The manifold valves do not require SIL certification because they are not connected to an emergency shut down system.Introducing the electric actuators to the manifold valve will not change the valve selection philosophy.

Challenges Associated with the Bypass Valves of Control Valves in a Seawater Service

Modern processing plants use a variety of control loop networks to deliver a finished product to the market.Such control loops,like control valves,are designed to keep process variables such as pressure,temperature,speed,flow,etc.within the appropriate operating range and to ensure a quality product is produced.All control valves have a bypass so that production can proceed if maintenance is needed for the control valve as part of the control loop.The important point is that in both operation and maintenance situations,the bypass valve and the control valve should have approximately the same flow capacity to provide nearly the same amount of pressure.This paper presents a case study in seawater service on the selection of manual bypass valves for a 16″control valve in class 150 and titanium material.A 16″butterfly valve of class 150 was chosen for the control valve bypass,which provided a much higher flow capacity than the control valve.In this paper,four solutions are recommended to achieve the same coefficient value(Cv)for the control and bypass valve.Using the reduced size butterfly valve could be the cheapest and best solution.On the other hand,selecting the same control valve for bypass line is the most expensive but maybe the most reliable solution.Using a flow orifice for throttling could be ranked as the second expensive option and the second reliable one.Selection of butterfly valve for throttling is the second cheapest option,but it has the least reliability.Different parameters such as space and weight saving,cost as well as reliability have been considered in evaluation of different solutions.

An In-depth Analysis for Optimal Cable Tray Support Span

Nowadays,it is crucial to reduce the cost of the overall project so that the competitiveness of offshore oil and gas without compromising on quality or safety can be achieved.This study investigates how to define the longest cable tray support span considering constructability in order to reduce the number of supports which is a chief cost of a cable tray system.This study presents not only material and geometry frequently used for cable tray but also the formula to estimate the maximum cable load which can be installed within cable tray.To verify the longest span without increasing the crosssection of cable tray,finite element modelling approach was employed based on ANSYS and comparisons were made between numerical analysis and simplified hand calculation.The constructability for the longer span obtained from finite element analysis has been validated in view of manual handling of the cable tray.It is shown that the optimal span suggested in this paper can lead to a better economic benefit without degrading the constructability.For instance,as the span is longer,the cost of material as well as construction manpower can be saved.It is also expected that this approach will contribute to enhance the competitiveness of offshore oil and gas.

Experimental Study of Stable Surfaces for Anti-Slug Control in Multi-phase Flow

Severe slugging flow is always challenging in oil ＆ gas production, especially for the current offshore based production. The slugging flow can cause a lot of problems, such as those relevant to production safety~ fatigue as well as capability. As one typical phenomenon in multi-phase flow dynamics, the slug can be avoided or eliminated by proper facility d^sign or control of operational conditions. Based on a testing facility which can emulate a pipeline-riser or a gas-lifted production well in a scaled-down manner, this paper experimentally studies the correlations of key operational parameters with severe Slugging flows. These correlations are reflected through an obtained stable surface in the parameter space, which is a natural extension of the bifurcation plot. The maximal production opportunity without compromising the stability is also studied. Relevant studies have already showed that the capability, performance and efficiency of anti-slug control can be dramatically improved if these stable surfaces can be experimentally determined beforehand. The paper concludes that obtaining the stable surface on the new developed map can significantly improve the production rate in a control scheme. Even though the production rate can be further improved by moving the stable surface using advanced control strategies, the constant inputs can in some cases be preferable due to the easier implementation.