Woodside Energy Ltd Research Articles

The importance of optimal geological zonation and choice of rock parameters in dynamic reservoir simulation: a case study for the Laminaria field

The Laminaria field, located offshore in the Timor Sea, is one of Australia’s premier oil developments operated for many years by Woodside Energy Ltd. First production was achieved in 1999 using a state-of-the-art floating production storage and offloading vessel, the largest deployed in Australian waters. As is typical, dynamic reservoir simulation was used to predict reservoir performance and forecast production and ultimate recovery. Initial models, using special core analysis (SCAL) laboratory data and pseudos, covered a range of approaches, field and conceptual models. Initial coarser models also used straight-line relative permeability curves. These models were later refined during history matching. The success of simulation studies depends critically on optimal gridding, particularly vertical definition. An objective of the study presented is to demonstrate the importance of optimal and detailed vertical zonation using Routine Core Analysis data and a range of Hydraulic Flow Zone Unit models. In this regard, the performance of a fine-scale model is compared with three alternative, more traditional and coarse models. Secondly the choice of SCAL rock parameters may also have a significant impact, particularly relative permeability. This paper discusses the use of the more recently developed Carman-Kozeny based SCAL models, the Modified Carman-Kozeny Purcell (MCKP) model for capillary pressure and the 2-phase Modified Carman-Kozeny (2p-MCK) model for relative permeability. These models compare favourably with industry standard approaches, the use of Leverett J-functions for capillary pressure and the Modified Brooks-Corey model for relative permeability. The benefit of the MCK-based models is that they have better functionality and far better adherence to actual laboratory data.

Cargo scheduling decision support for offshore oil and gas production: a case study

Woodside Energy Ltd (Woodside), Australia’s largest independent oil and gas company, operates multiple oil and gas facilities off the coast of Western Australia. These facilities require regular cargo shipments from supply vessels based in Karratha, Western Australia. In this paper, we describe a decision support model for scheduling the cargo shipments to minimize travel cost and trip duration, subject to various operational restrictions including vessel capacities, cargo demands at the facilities, time windows at the facilities, and base opening times. The model is a type of non-standard vehicle routing problem involving multiple supply vessels—a primary supply vessel that visits every facility during a round trip taking at most 1 week, and other supply vessels that are used on an ad hoc basis when the primary vessel cannot meet all cargo demands. We validate the model via test simulations using real data provided by Woodside.

Woodside Energy Ltd: pioneer in cognitive computing, artificial intelligence and robotics

Cognitive computing is a new disruptive technology with the potential to reshape the oil and gas industry across the entire value chain. For Woodside Energy Ltd (Woodside), embracing this technology is an opportunity to save time, drive efficiency and reduce costs. In 2015, Woodside collaborated with IBM and deployed a cognitive computing system (IBM’s Watson) into its business. The system focuses on capturing the vast proprietary database of knowledge on Woodside’s major capital projects. Today, the Watson proof-of-concept has been successfully deployed by the science function into the business and is now under the care of the projects function. Moreover, it is undergoing continuous advances through further machine learning, additional ingestion of documentation and features linking the cognitive computer system with existing subject matter experts. Given the success of the first pilot program, Woodside is continuing to rapidly leverage cognitive technologies in other areas of the business. In mid-2016, Woodside deployed Watson for drilling events using IBM’s Watson Explorer – Advanced Addition. This program identifies and classifies a wide variety of geological drilling events allowing Woodside’s geoscience team to provide more timely and accurate assessment of potential risks for well design. Woodside continues to develop several other business solutions using these platforms in areas as diverse as continuous improvement, business management, maintenance campaigns, legal advice, general management and robotics. This presentation shares Woodside’s lessons and insights derived from its journey across multiple forms of cognitive technology and provides insights as to the state-of-the-art and adaptation of these systems to achieve specific goals.

A mixed-integer linear programming model for optimal vessel scheduling in offshore oil and gas operations

This paper introduces a non-standard vehicle routing problem (VRP) arising in the oil and gas industry. The problem involves multiple offshore production facilities, each of which requires regular servicing by support vessels to replenish essential commodities such as food, water, fuel, and chemicals. The support vessels are also required to assist with oil off-takes, in which oil stored at a production facility is transported via hose to a waiting tanker. The problem is to schedule a series of round trips for the support vessels so that all servicing and off-take requirements are fulfilled, and total cost is minimized. Other constraints that must be considered include vessel suitability constraints (not every vessel is suitable for every facility), depot opening constraints (base servicing can only occur during specified opening periods), and off-take equipment constraints (the equipment needed for off-take support can only be deployed after certain commodities have been offloaded). Because of these additional constraints, the scheduling problem under consideration is far more difficult than the standard VRP. We formulate a mixed-integer linear programming (MILP) model for determining the optimal vessel schedule. We then verify the model theoretically and show how to compute the vessel utilization ratios for any feasible schedule. Finally, simulation results are reported for a real case study commissioned by Woodside Energy Ltd, Australia's largest dedicated oil and gas company.

An innovative method for project control in LNG project through 5D CAD: A case study

Abstract Current studies on 5D CAD have been limited to either description of concept or automatic generation of quantities. Few have attempted to explore the other capabilities of 5D CAD. Project cost control and schedule control are very important for successful project delivery, while existing studies on computer based project control tools have largely focused only on schedule control. This paper fills the gap by investigating the possibility of using 5D CAD for project cost and schedule control. Initiated by Woodside Energy Ltd, a prototype of a 5D CAD system has been developed specifically for Liquefied Natural Gas (LNG) industry. The system was tested with the project data of an example module from an LNG plant provided by Woodside Energy Ltd. The functions of the system include: visualization of schedule data and verification of cost in real time and facilitation of periodic planning and progress reporting. It is concluded that 5D CAD could be a very powerful project cost and progress control tool.

Field experiences with virtual metering technology

This paper presents field experiences with the implementation of virtual well metering technology on the North West Shelf (NWS) of Western Australia. This technology is used to obtain well-by-well flow rate estimates using conventional pressure and temperature instrumentation in a wellbore and Christmas tree without the need for expensive multiphase flow meters. Best practices in project execution—including specifications, acceptance testing and commissioning procedures—are presented for deploying this advanced technology. The paper focusses on two NWS gas-condensate developments operated by Woodside Energy Ltd (WEL) on behalf of the NWS joint venture partners: the Perseus over Goodwyn (PoG) project, which is a four well subsea development of the Perseus and Searipple fields that tie back to the Goodwyn A platform; and a three well subsea development for the Angel field. The PoG virtual metering system (VMS) was commissioned in October 2007 and the Angel VMS more recently in February 2009. The paper compares field data and shows that this technology has provided very reliable and accurate flow rate predictions; historical data suggests that monthly reconciliation factors as low as 3–5% can be achieved. Virtual metering systems are a cost effective and reliable means to obtain well-by-well flow rates. Besides enabling better reservoir management, these well metering systems are easily integrated with real-time pipeline monitoring systems to enable reliable subsea operations. An integrated virtual metering and pipeline management system that includes look-ahead forecasting capabilities and guidance for real-time flow assurance on operational issues, such as hydrate formation and detection of restriction, is being developed for the Pluto field.

The challenges of seismic acquisition in a remote and sensitive marine environment: Scott Reef, Western Australia

Woodside Energy Ltd, as operator of the Browse LNG Development, recently acquired two seismic surveys at Scott Reef, Western Australia. The surveys were important steps towards acquiring full seismic coverage over the Torosa gas field, part of which underlies Scott Reef The Maxima 3D marine seismic survey, conducted in late 2007, was a conventional towed streamer survey. This was followed in May 2008 by the Gigas 2D transition zone survey in the shallow waters of north Scott Reef, and Woodside’s first experience with ocean bottom cable (OBC) seismic technology. Each survey presented unique challenges during the planning, regulatory approval and acquisition stages. Scott Reef comprises two coral atolls located on the outer continental shelf of northwest Australia, approximately 400 km north of Broome. The only permanently emergent land is a small sand cay (Sandy Islet, Fig. 1), although the reef crests of both atolls are exposed at low tide. Outside the reefs the seafloor drops away rapidly, with water depths of about 350 m to the east, increasing to more than 1,000 m to the west. South Scott Reef lagoon is open to the north, with water depths increasing to about 50 m before deepening abruptly into the channel between the two reefs. North Scott Reef lagoon is shallower—generally less than 25 m—and is connected to the ocean by two narrow channels. Semi-diurnal tides with a range of up to 4.6 m produce strong tidal currents in and near these channels. Small, steep-sided coral heads, or bombies, are common throughout the lagoons, especially in water less than 25 m deep.

The effects of marine seismic acquisition in a coral reef environment: results from a multi-disciplinary monitoring program at Scott Reef, Western Australia

In September 2007 Woodside Energy Ltd, as operator of the Browse LNG Development , conducted the Maxima three-dimensional marine seismic survey (Maxima) at Scott Reef, a shelf-emergent coral atoll located in the Indian Ocean approximately 425 km north of Broome, Western Australia Implementation of the survey followed extensive state and Commonwealth environmental approvals processes that began more than 12 months earlier. The survey drew regulator and stakeholder attention, with focus on the uncertainties associated with predicting impacts on Scott Reef marine environment as a result of exposure to airgun noise emissions. Ministerial conditions for approval of the survey concluded that significant impacts were unlikely (Woodside 2008), but required Woodside to address the inherent uncertainties through implementation of a suite of research and monitoring activities prior to, during and after Maxima. Most were completed in on site Scott Reef as part of a field verification study, conducted in advance of the full data acquisition phase of Maxima. These monitoring studies showed that the actual effects of exposure to an airgun array were lower than predicted and established new sound exposure thresholds.

Use of innovative technology to manage impacts in a sensitive environment

In 2008 Woodside Energy Ltd, as operator of the Browse LNG Development, completed the Torosa–6 appraisal well in the south lagoon of Scott Reef, which is about 425 kilometres north of Broome, Western Australia. The well was drilled with the Wilcraft jack-up rig (Fig. 1) and was part of the appraisal program for the Torosa gas field. About half of this field lies beneath the shallow-water coral atolls of Scott Reef. The well involved a number of innovative technologies to minimise the environmental footprint while achieving the appraisal objectives. The approach adopted a custom-built riserless recovery system to collect the cuttings and mud from the riserless section of the well, combined with a purpose built cuttings containment and slurrification system to recover the cuttings and mud from the well for disposal away from Scott Reef. This well represents a significant demonstration of the industry’s responsible approach to operating in sensitive areas. The drilling of the Torosa–6 well provided a number of challenges due to the environmental sensitivity of the area, requirement to obtain regulatory approval at both the state and Commonwealth levels and the need take stakeholder expectations into account.

CAN SUSTAINABLE DEVELOPMENT THINKING BE APPLIED TO NEW OILFIELDS? A CASE STUDY OF THE EARLY STAGES OF THE ENFIELD AREA DEVELOPMENT IN AN ENVIRONMENTALLY AND SOCIALLY SENSITIVE AREA

Can development of a finite resource, such as oil, be consistent with sustainable development? Sustainable development involves meeting the needs of current and future generations through simultaneous consideration of environmental, social and economic aspects (referred to as the triple bottom line).Since 1998, Woodside Energy Ltd (Woodside) has discovered three oil fields in the WA-271-P Permit area offshore North West Cape, northern Western Australia. The fields are some 20 km from the boundary of the Ningaloo Marine Park.The first part of this paper presents a case study of the Enfield Area Development. It describes the approach taken to simultaneously manage environmental, social and economic considerations while planning for the development of oil fields in exploration permit WA-271-P.A range of measures have been employed that are considered examples of best practice for the petroleum industry in Australia, including:early commitment to a range of responsible environmental management measures in design; a comprehensive community engagement program, with links to the development and environmental assessment processes; and pioneering environmental research.Novel methods of establishing environmental and social issues as key priorities within the Woodside development team have been successfully implemented.The case study provides by giving an overview of the most significant environmental risks associated with the proposed development, and concludes that the development does not represent a significant risk to the environment.The second part of the paper then addresses the question of whether oilfields can be developed sustainably, looking at current views from the literature, and whether the approach outlined in the case study can be considered sustainable.While the project is still in an early stage of development, it provides a strong indication that oil development can be consistent with current thinking on sustainability, provided that current needs, which include a dependence on fossil fuels, and future needs, such as preservation of the productive and social value of the environmental resource base, are balanced simultaneously. The paper concludes that oil development, even in an environmentally and socially sensitive area, can help facilitate the transition to a more sustainable future.

DEEPWATER EXPLORATION: NORTH WESTERN AUSTRALIA COMPARED WITH GULF OF MEXICO AND MAURITANIA

Some of Australia’s deepwater frontiers are opening up for exploration, with existing and new companies taking acreage positions. Despite favourable fiscal terms and political stability, interest levels have not matched those in international hot spots due to key differences in perceived prospectivity.In this paper, Australia’s deepwater plays in the Northern Carnarvon Basin are compared and contrasted with deepwater plays in the Gulf of Mexico and offshore Mauritania. This comparison is largely based on Woodside Energy Ltd’s exploration pursuits in these areas.The Northern Carnarvon Basin deepwater plays are principally an extension of shallower water petroleum fairways, submerged to greater water depths by the absence of the Tertiary progradational, carbonate shelf sequence. Trap types and reservoir-seal pairs in the deepwater prospects are similar to their shallow water counterparts, but extensive deepwater areas carry an increased exploration risk due to the absence of this shelf overburden to load the Jurassic source rocks into the oil expulsion window. Hydrocarbons generated typically comprise dry gas from deeper Triassic source rocks, often trapped in sub-commercial quantities. Although the basin lacks a world class, widespread, oil-generating source rock, recent deepwater commercial oil discoveries in the Exmouth Sub-basin indicate the existence of a localised sweet spot associated with a Late Jurassic depocentre, similar to the proven Barrow-Dampier Subbasins located in shallower waters.In contrast, Woodside’s deepwater Gulf of Mexico and offshore Mauritania plays combine deepwater depositional systems with present day deepwater. They have reservoir-quality turbidite sandstones, well imaged on excellent quality 3D seismic, sealed by deep marine shales and charged by world class, organic-rich, prolific source rocks. Salt tectonics, shale diapirism and sloperelated slumping and thrusting have generated appealing structural styles, resulting in multiple play types and a density of prospects and leads not seen in Australia’s deepwater frontiers to date.Although elements of these plays are present at some locations in Australia’s deepwater, nowhere yet have all the required exploration ingredients for a major oil province been found juxtaposed as in the proven Gulf of Mexico and the highly prospective offshore Mauritania. Political stability and relatively favourable fiscal terms remain essential in attracting the exploration investment dollar to Australia’s deepwater.

THE KYOTO PROTOCOL- THREATS AND OPPORTUNITIES

In 1997, Australia signed the Kyoto Protocol under which it had been assigned what will become a legally binding emissions cap of 108% of its 1990 emissions. This target may be appropriate for our national circumstances but will be challenging to meet. This paper examines the way Woodside Energy Ltd is addressing the threats and opportunities raised by the Kyoto Protocol.The major risk to Woodside's business arises from the division of the Protocol into Annex B and non-Annex B. Australia is in Annex B, which is composed primarily of developed countries that have assigned emission amounts that will be legally binding when the protocol comes into force and is ratified.Meeting the Australian target and the global greenhouse emission reduction objective will require increasing the substitution of gas into national fuel mixes. Natural gas, including LNG, has the lowest lifecycle emissions of any fossil fuel.The Australian LNG industry is the only major Annex B supplier of LNG to Japan and thus would be at a severe competitive disadvantage if the costs of unilaterally imposed abatement policies and measures were applied to the industry in Australia that were not applied to its international competitors. The LNG industry is seeking differential treatment to alleviate this risk. Woodside has proposed a solution, put forward in this paper, that a scheme be negotiated into the Protocol at CoP6, allowing for the repatriation of credits from the LNG fuel cycle to the exporting country. This would permit fair competition across all LNG exporters.Woodside is keen to undertake its fair share of emission reduction and has already implemented some projects that have been successful in this regard. Further implementation of beyond no regrets projects relies on the Commonwealth resolving the recognition for early action question. A trial framework for making decisions on early abatement projects is described.Woodside is also investigating potential opportunities arising from the Protocol. Progress is reported on early investigation into clean development mechanism (CDM) projects and greenhouse abatement research and development (R&D). Sink enhancement studies are nearly complete and a detailed business case is under preparation.

DRILLING FLUIDS AND THEIR ENVIRONMENTAL MANAGEMENT: THE INTRODUCTION OF AN ESTER OXYGEN-BASED FLUID

An oxygen-based fluid (OBF) containing fish oil ester was introduced in October 1998 for the extended reach drilling campaign on the Goodwyn Alpha platform.The introduction involved multiple discussions with the West Australian Department of Minerals and Energy (WADME) and adherence to the risk-based approach from both WADME and the Woodside Energy Ltd (WEL) policies and standards for well engineering operations.The WEL approach to the introduction of the fluid was to address the issues associated with the use and discharge of the ester.The issues included the development of a fluid system which was optimal for extended reach wells, engineering solutions to minimise the amount of fluid discharged, and gaining a better understanding of the environmental impact of the fluid to local conditions.To minimise the volume discharged, the platform was refurbished including an upgrade to state-of-the-art solids removal equipment and modifications to the fluid system to ensure double discharge barriers.Baker Hughes Inteq conducted an extensive development program of the ester fluid system, involving more than 5,000 man hours of laboratory work.In conjuction with Curtin University of Technology, ecotoxicity testing was conducted to determine the acute impact on local species on the North West Shelf. A closed- bottle anaerobic biodegradation test was developed by Geotechnical Services to compare biodegradation rates of different fluids.By minimising the volume discharged and evaluating the impact of the discharge on the marine environment, WEL has demonstrated a comprehensive risk-based approach for the introduction of an OBF to WEL's platform and mobile drilling operations.