Topside payloads range from 5 to 50,000 tons, producing oil, gas, or both. A vast array of production systems is available today (see Figure 1). The concepts range from fixed platforms to subsea compliant and floating systems. In 1859, Col. Edwin Drake drilled and completed the first known oil well near a small town in Pennsylvania, U.S.A. This well, which was drilled with cable tools, started the modern petroleum industry.
This field produces from a structure that lies above a deep-seated salt dome (salt has been penetrated at 9,000 ft) and has moderate fault density. A large north/south trending fault divides the field into east and west areas. There is hydraulic communication across the fault. Sands were deposited in aeolian, fluvial, and deltaic environments made up primarily of a meandering, distributary flood plain. Reservoirs are moderate to well sorted; grains are fine to very fine with some interbedded shales. There are 21 mapped producing zones separated by shales within the field but in pressure communication outside the productive limits of the field. The original oil column was 400 ft thick and had an associated gas cap one-third the size of the original oil column. Porosity averages 30%, and permeability varies from 10 to 1500 md.
Case studies can be instructive in the evaluation of other coalbed methane (CBM) development opportunities. The San Juan basin, located in New Mexico and Colorado in the southwestern U.S. (Figure 1), is the most prolific CBM basin in the world. It produces more than 2.5 Bscf/D from coals of the Cretaceous Fruitland formation, which is estimated to contain 43 to 49 Tscf of CBM in place. In the 1970s, after years of encountering gas kicks in these coals, operators recognized that the coal seams themselves were capable of commercial gas rates. CBM development benefited greatly from drilling and log data compiled from previous wells targeting the deeper sandstones and an extensive pipeline infrastructure that was built to transport conventional gas. These components, along with a U.S. federal tax credit and the development of new technologies such as openhole-cavity completions, fueled a drilling boom that resulted in more than 3,000 producing CBM wells by the end of 1992. The thickest Fruitland coals occur in a northwest/southeast trending belt located in the northeastern third of the basin. Total coal thickness in this belt locally exceeds 100 ft and individual coal seams can be more than 30 ft thick. The coals originated in peat swamps located landward (southwest) of northwest/southeast trending shoreline sandstones of the underlying Pictured Cliffs formation. The location of the thickest coals (Figure 1) coincides with the occurrence of overpressuring, high gas content, high coal rank, and high permeabilities in the San Juan fairway ("fairway"). The overpressuring is artesian in origin and is caused by water recharge of the coals through outcrops along the northern margin of the basin. This generates high vertical pressure gradients, ranging from 0.44 to 0.63 psi/ft, which allow a large amount of gas to be sorbed to the coal. Coal gas in the San Juan basin can contain up to 9.4% CO2 and 13.5% C2 . Chemical analyses suggest that thermogenic gases have been augmented by migrated thermogenic and secondary biogenic gas sources, resulting in gas contents ranging up to 700 ft 3 /ton. Coal rank in the fairway ranges from medium- to low-volatile bituminous and roughly coincides with those portions of the basin that were most deeply buried. Southwest of the fairway, Fruitland coals are typically 20 to 40 ft thick and are considerably underpressured with vertical pressure gradients in some areas of less than 0.20 psi/ft. The low gradients are attributable to low permeabilities, low recharge rates along the southern rim of the basin, and hydraulic isolation from the fairway area.
This page provides a reservoir management case study for an offshore sandstone field under solution-gas drive in which water and gas injection techniques have been implemented. The highly faulted structure produces from six different productive horizons. The depositional settings range from deepwater marine turbidite fans through near shore and delta san facies to fluvial deposits. The reservoir has been developed from two separate platforms and has an extensive subsea development of satellite fields. Six subsea fields have been developed with 28 subsea producing wells.
Carbonate reservoirs are extremely challenging for reservoir modeling and flow simulation due to their high heterogeneity and the complexity of controls on the porosity and permeability. The porosity and permeability may be connected or weakly connected, which can cause difficulties in coarse grid design and upscaling of flow. We report on the application of a recently developed "Diffuse Source" upscaling approach here applied to the upscaling of a high resolution 3D carbonate reservoir model. A high-resolution 3D geological model of the Amellago carbonate outcrop was utilized for analysis. This model, which has similar stratigraphy, structure and diagenetic controls as Middle East reservoirs, has proven to be a challenge for existing layer upgridding and flow-based upscaling approaches. We utilize flow-based "Diffuse Source" upscaling to obtain the intercell transmissibility and well indices, as this approach has improved localization and resolution compared to steady state calculations, and also allows us to distinguish between well connected and weakly connected sub-volumes. We report on the performance of the statistical layer upgridding approaches used to design the flow simulation grid from the underlying 3D geologic model, and the impact of the choice of the heterogeneity measure (velocity error, time of flight error, or a combination of the two).
The outlook in the UK is a case study of the squeeze facing E&P in other basins where operators are trying to pay to sustain production with discoveries, while plugging and abandoning old wells, all paid for by the lean cash flow due to low oil prices. Subsea inspection/repair/maintenance services have traditionally relied on vessel-based, ROV, or diver operations. In the longer term, identifying significant incremental savings in these operations is not sustainable and an innovative approach deploying digital technologies is being investigated. The deal gives Equinor an additional 7.5% ownership stake in the Njord redevelopment project and associated tiebacks in the Norwegian Sea, and potentially raises Faroe’s value in the midst of a hostile takeover attempt by DNO. Startup comes 8 months after the initial discovery in March, marking the second successful tieback since 2017 to the Beryl Alpha platform in the UK North Sea.
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.
Startup comes 8 months after the initial discovery in March, marking the second successful tieback since 2017 to the Beryl Alpha platform in the UK North Sea. The rising oil production and produced water volumes in the Permian are expanding the scope and scale of recycling. Apache is targeting 50% of its frac water to be made up from recycled produced water this year. Industry CIOs examine the challenges operators and service companies face in understanding cybersecurity threats.
The startup of a second FPSO will add 115,000 BOPD to the deepwater project offshore Angola, bringing overall production capacity to 230,000 BOPD. Commissioning is complete and Bechtel has turned over care, custody, and control of Train 1 to Cheniere, It's the first liquefaction train placed into operation in a greenfield facility in the lower 48 states. Current production from the phase is 400 MMcf/D and expected to peak at 700 MMcf/D. A third phase also is slated to come on stream this year. McDermott will provide EPC, hookup, and commissioning of the Cassia C topsides, a jacket, and a bridge to link Cassia C with the existing Cassia B platform.
Ashtead Technology has acquired Louisiana-based subsea equipment rental and cutting services specialist, Aqua-Tech Solutions, as part of the company’s international growth plans in the US. High-fidelity 3D engineering simulations are valuable in making decisions, but they can be cost-prohibitive and require significant amounts of time to execute. The integration of deep-learning neural networks with computational fluid dynamics may help accelerate the simulation process. The chemical reactions creating buildups of scale that can clog a well can be replicated in a chemical lab, but researchers are finding many more variables on the surfaces of pipes that need to be considered. ExxonMobil signed a sales and purchase agreement with Zhejiang Provincial Energy Group for LNG supply.