The majority of offshore fields have been developed with conventional fixed steel platforms. One common feature of fixed steel structures is that it is essentially "fixed" (i.e., it acts as a cantilever fixed at the seabed). This forces the natural period to be less than that of the damaging significant wave energy, which lies in the 8- to 20-second band. As the water depth increases, these structures begin to become more flexible, and the natural period increases and approaches that of the waves. The consequence of this is the structure becomes dynamically responsive, and fatigue becomes a paramount consideration.
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.
This paper summarizes a technology using SMP to provide downhole sand control in openhole environments. With multistage operations becoming the industry norm, operators need easily deployable diversion technologies that will protect previously stimulated perforations and enable addition of new ones. This paper reviews several aspects of the use of in-stage diversion. Development of a new polymer composite that degrades via hydrolysis in hot water or brine holds potential for use in structural applications for intervention-less downhole tools. The polymer-injection project in the Dalia field, one of the main fields of Block 17 in deepwater Angola, represents a world first for both surface and subsurface aspects.
Polymer flooding in sensitive areas can require the transport of polymer fluids over long distances. Conventional wisdom limits transport distance or degradation occurs. This paper argues that critical velocity, not distance, is the controlling factor. Polymer flooding has been used to enhance the production of oil from mature fields in Oman. This article discusses the trial of several approaches to improve the treatment of water produced from these fields.
Researchers from Chevron are looking into a new approach to understand the drivers of polymer hydration. How might this affect the design of mixing systems in the field, and could it affect offshore EOR applications? Fluid Efficiency and Rhapsody Venture will partner to refine and launch a new molecular technology to improve the flow in pipelines. In this second article of a series covering water management in hydraulic fracturing (HF) in unconventional resources, the properties and characteristics of the flowback fluids are discussed, together with the general categories of technologies that are best suited to treat them. This is the first of several articles on the subject of water management for unconventional hydraulic fracturing.
We don’t include a structure like the Eiffel Tower with separators, pumps, and compressors on the top observation platform in an onshore development plan. And yet, how many jacket platforms are there around the world? Production from an offshore Angola field has been decreasing because of subsea pressure declines amid water-cut increases and limited gas compressor capacity. The development process leading to the selection of high-boosting multiphase pumps is described. In maturing oil wells, oil production is often restricted as reservoir pressure depletes.
This paper covers the staged field-development methodology, including analysis and evaluation of various development concepts, that enabled the company to optimize both completion design and artificial-lift selection, reducing downtime and lowering operating costs by nearly 50%. The First Eocene is a multibillion-barrel heavy-oil carbonate reservoir in the Wafra field, located in the Partitioned Zone between Saudi Arabia and Kuwait. After more than 60 years of primary production, expected recovery is low and provides a good target for enhanced-oil-recovery processes. This paper studies the technical and economic viability of this EOR technique in Eagle Ford shale reservoirs using natural gas injection, generally after some period of primary depletion, typically through long, hydraulically fractured horizontal-reach wells. This paper provides a robust methodology for miscible CO2 WAG experimental-data acquisition and history matching.
BP and partners have sanctioned the Azeri Central East project, the next stage of development of the giant Azeri-Chirag-Deepwater Gunashli oilfield complex in the Azerbaijan sector of the Caspian Sea. 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. If sanctioned and developed, the deepwater Pecan field would be Ghana’s fourth producing offshore field. First oil is expected 35 months after sanction, which could come as early as this year. Are Deepwater Projects Due for a Revival?
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. Sanctioned in 2014, the project is the largest deepwater offshore development in Angola. It will produce an estimated 230,000 BOPD from six different fields at peak. Production from an offshore Angola field has been decreasing because of subsea pressure declines amid water-cut increases and limited gas compressor capacity. The development process leading to the selection of high-boosting multiphase pumps is described.