Gas injection is a proven EOR method in the oil industry with many well-documented successful field applications spanning a period of more than five decades. The injected gas composition varies between projects, but is typically hydrocarbon gas, sometimes enriched with intermediate components to ensure miscibility, or carbon dioxide in regions such as the Permian Basin, where supply is available at an attractive price.
Miscible nitrogen injection into oil reservoirs, on the other hand, is a relatively uncommon EOR technique because nitrogen often requires a prohibitively high pressure to reach miscibility. Unlike other injection gases, the minimum miscibility pressure for nitrogen decreases with increasing temperature. In fact, in deep, hot reservoirs containing volatile oil, nitrogen may develop miscibility at a pressure similar to the MMP for hydrocarbon gas or carbon dioxide. The phase behavior is more complicated than what can be captured by correlations and hence requires equation-of-state calculations.
Results from a recent EOR screening study in ADNOC indicate that a couple of high-temperature oil reservoirs in Abu Dhabi may be potential targets for miscible nitrogen injection. This paper discusses key aspects of the EOS modeling. Advanced gas injection PVT data are available to enable a fair comparison between nitrogen, carbon dioxide and lean hydrocarbon gas. In this work, we have modelled and analyzed the phase behavior of two volatile oil systems with respect to nitrogen, hydrocarbon gas, and carbon dioxide injection, as part of a reservoir simulation study, which will be covered in a subsequent publication; see
Waterflooding is the main technic to recover hydrocarbons in reservoirs. For a given set of wells (injectors and producers), the choice of injection/production parameters such as pressures, flow rates, and locations of these boundary conditions have a significant impact on the operating life of the wells. As a large number of combinations of these parameters are possible, one of the critical decision to make is to identify an optimal set of these parameters. Using the reservoir simulator directly to evaluate the impact of these sets being unrealistic considering the required number of simulations, a common approach consists of using response surfaces to approximate the reservoir simulator outputs. Several techniques involving proxies model (e.g., kriging, polynomial, and artificial neural network) have been suggested to replace the reservoir simulations. This paper focalizes on the application of artificial neural networks (ANN) as it is commonly admitted that the ANNs are the most efficient one due to their universal approximation capacity, i.e., capacity to reproduce any continuous function. This paper presents a complete workflow to optimize well parameters under waterflooding using an artificial neural network as a proxy model. The proposed methodology allows evaluating different production configurations that maximize the NPV according to a given risk. The optimized solutions can be analyzed with the efficient frontier plot and the Sharpe ratios. An application of the workflow to the Brugge field is presented in order to optimize the waterflooding strategy.
The strategy supports the Maximise Economic Recovery from UK Oil & Gas Strategy and Vision 2035, whose goal is to achieve £140 billion additional gross revenue from UKCS production by that time. The round marked a continuation of a recent trend on the UKCS in which lesser-known firms and newcomers have gained stature, replacing more-familiar, bigger operators that have pared down their North Sea positions. Some 3,000 people and counting intrigued by UK oil and gas data have signed up for access to the country’s new National Data Repository. What motivated the OGA to make the data available to the public, and what can the public do with the data? A recent spike in production has engendered a cautiously optimistic outlook for the UKCS, but will it do anything to stave off the overall decline of the mature basin?
Anchored by the Khaleesi-Mormont and Samurai fields, the King’s Quay FPS will receive and process up to 80,000 B/D of crude oil. UK operator Trident Energy is entering Brazil while Australian firm Karoon Energy is expanding its position in the country. Both will try to boost output from already-producing assets. The world’s largest oil producer has awarded $18 billion in engineering, procurement, and construction contracts as part of its Marjan and Berri expansion projects. The Norwegian operator will increase its ownership of the giant Johan Sverdrup field before the field commences oil production this November.
Australia’s BHP Billiton and the recently acquired Anadarko Petroleum submitted the largest dollar totals of high bids in US Gulf of Mexico Lease Sale 253. Moving their directional drillers into their Houston real-time remote operations centers has improved drilling efficiency for two of the top shale producers. In its first 50 years, LNG has become the world’s fastest-growing gas supply source and is now part of an upheaval in the global energy market. Today, the sector stands at a crossroads, and the industry must adopt new thinking to address current and future needs of buyers, sellers, and consumers. The new well control rule is evidence that memories of the Macondo blowout remain a powerful force for caution.
Bravo is the second of four platforms to be decommissioned and removed from the Brent field, following Brent Delta in 2017. The field has produced approximately 3 billion boe since 1976. A panel of UK government officials and industry executives discuss opportunities to increase efficiency in North Sea decommissioning programs.
The subsea tieback is expected to start up in 2021. This is Shell’s second major development on a tieback in the US Gulf of Mexico, following Kaikias’ startup in May. Bravo is the second of four platforms to be decommissioned and removed from the Brent field, following Brent Delta in 2017. The field has produced approximately 3 billion boe since 1976. First cargo from the world’s largest floating LNG project comes in the midst of low LNG prices sparked by a global supply boost.
The decision comes a year after Neptune stopped production from the North Sea gas field, and 4 months after it submitted decommissioning plans to the UK authorities. Bravo is the second of four platforms to be decommissioned and removed from the Brent field, following Brent Delta in 2017. The field has produced approximately 3 billion boe since 1976. After producing for 43 years, the Statfjord A platform will cease production in 2022. Decommissioning and abandonment comes with its share of unexpected surprises, but many of those surprises could be avoided merely through better planning and care.
With the purchase, the growing, privately-held Chrysaor Holdings will expand its UK North Sea production to 185,000 BOE/D. The state-run offshore company has found a gas and condensate field that holds an estimated 250 million BOE. The latest example of the offshore sector's march toward automated wellbore construction will take shape later this year in the North Sea. Just 2 months after issuing more than a hundred licenses, the Oil and Gas Authority begins the process again for a whole new set of blocks. The company announced it would “initiate the process” of marketing its UK Central North Sea fields as part of a portfolio review.
The Turritella FPSO (Figure 1 above) is the deepest floating production system in the world and presented many challenges to successful execution of the surface host facilities. The long-term decommissioning of the historic Brent field has necessitated redevelopment of the younger Penguins field in the North Sea, where the UK hopes to see more revival projects in the coming years. Despite major advancements in deepwater projects in the Gulf of Mexico, FPSO usage has yet to increase. This paper describes the CLOV deepwater megaproject in Block 17 offshore Angola, which cost USD 8.4 billion to first oil. This paper describes the measures put in place so that the mooring system of the Gryphon Alpha FPSO could be replaced and reconnected on an efficient schedule.