Offshore oil and gas fields are complex and capital intensive projects, involving specialized technologies, techniques and vessels, precise planning and extensive support mechanisms. The management of these operations also has to take into account the critical issues of safety and environmental protection.
The project plan of Offshore Field Development explores the stages involved in offshore oil and gas production, along with the specialist vessels supporting it, from exploration and surveying to drilling, construction and supply.
Production from deep water fields began in earnest just twenty years ago. Currently deep water developments provide about 10% of global oil supply. In the future, an increasing percentage of the world’s oil and gas supply will come from deep water. An assessment of existing projects revealed that a significant percentage under-performed technically and commercially. Inadequate attention to and poorly executed field development planning (FDP) was identified as a leading causal factor.
With large capital outlays and increasingly complex developments, industry has acknowledged the need for a rigorous, structured development planning process to fully realize the commercial value of deep water projects.
The consortium of Noble and Delek, holds the right to explore Cyprus’ Aphrodite offshore block 12, in the Republic’s Exclusive Economic Zone (EEZ) as well as Leviathan and Tamar gas fields of Israel.
Four years after the initial exploration well in block 12 in Cyprus’ EEZ, US Noble Energy will submit its development plan for the Aphrodite well that holds a gross reserve of natural gas amounting to 4.50 – 5.00 trillion cubic feet. Cyprus has already engaged in talks with Egypt to explore ways of exporting natural gas in the neighboring country.
The criticality of good decision making at this stage is further stressed by the fact that the choice of a development strategy is of great consequence for the profitability of the project.
The Cyprus Hydrocarbons Company (CHC) and the Egyptian Natural Gas Holding Company (EGAS) are undertaking a technical study to examine a potential pipeline and onshore facilities option related to a possible future export of natural gas from “Aphrodite” to Egypt. The study will also examine the potential use of existing oil and gas infrastructure in Egypt.
CHC is also looking at developing a pipeline from “Aphrodite” to Cyprus for domestic use and “we are expecting that the volume of gas needed will be around 1 bcm per year for the next 20-25 years and of course this leaves a gas volume which can be exported.
Conceptual study
A concept is here defined by the installed production capacity of the platform and the option to increase this capacity during the production phase.
Engineering and construction
The engineering and construction phase does not contain any decisions, but carries out the decisions made in the conceptual study phase. Any pre-drilling of production wells decided in the conceptual study phase is done during this phase.
Field Deep water Planning (FDP) Overview
The FDP process involves a continuous interaction between three key elements: subsurface, well construction, and surface facilities . Regional considerations and site conditions play key roles in the decision making process. The goal is to select a facilities development plan that is compatible with the reservoir depletion plan while satisfying an Operator’s technical, risk and commercial requirement
Reservoir Characterization and Depletion Plan
The FDP process begins in earnest following a successful exploration and appraisal program. The first step is for the subsurface team (geologists, geophysicists, and reservoir engineers) to generate a robust model of the reservoir from seismic, well log and drill stem test data.
Well Construction and Intervention
The cost of drilling and completing deep water wells can often consume half the development budget because of the high spread rates of new generation, high capacity drilling rigs and drilling duration’s.
Site Characteristics
Field architecture and floating platform selection are strongly influenced by site-specific water depth, met-ocean conditions, seabed bathymetry and geotechnical conditions.
Surface Facility Building Blocks
A deep water facility development scenario can be constructed from the following building blocks: Sub-sea System, Drilling Platforms, Production Platform, Export System and Onshore Facilities. A sub-sea system consists of an assemblage of trees, manifolds, umbilical s and flow lines to a riser pipeline end termination (PLET).
