Field planning and development of Oil and Gas Reservoirs using GIS Technology
Field development process
Responding to the myriad of questions arising on how it is best to extract the
discovered fluids from the reservoirs and deliver the products to the market is a
daunting task. Also, to minimize CAPEX, OPEX and the risk of failure, while at
the same time maximizing the profits and meeting the environmental goals, is a
complex problem. At the early stages of a field development there is very little
reliable information available. However, based on what little information is
available, a number of field development scenarios can be investigated assuming
a series of potential outcomes of fluids contained within the reservoir(s).
Hence, the field development process is executed in a cyclic fashion. That is,
based on initial preliminary information field development scenarios that are
developed, then with the next revision of new data, the scenarios are modified
and normally reduced in total number. This process is repeated several times
before an optimum solution is reached. At the start of each cycle the phasing of
the development is also reconsidered. This consist of, the number of wells
needed to be drilled to reach a target production, the number of manifolds and
flowlines required to be installed and the corresponding offshore facilities for the
first phase of the development are identified. The CAPEX, OPEX and economic
factors are evaluated based on the total income from the field over the first
phase. The second phase components of the field are then added on and the
commercial implication studied. The trade offs between installation of
components in the first rather than the second phase of the development are
identified. Subsurface issues, location and environmental consideration, as well
as technical, commercial and geo-political constraints can further complicate the
field development team’s task. The field development process in the past has
been a time consuming and laborious task.
The field optimization and cost updating solution
As previously discussed to meet the field development challenges a GIS based
system for the integration of management, commercial and multi-discipline
engineering issues have been developed for “planned” and “mature” fields both
offshore and onshore.
The system provides an interactive graphical representation of the scenario
models in the GIS front-end and exports this information via the GIS Interface to
the Cost Model showing immediate cost implications brought about by changes
within a given scenario. It also provides a platform for the field development
team to record subsurface geohazards and environmental, technical, and
commercial concerns while examining the interaction between large numbers of
parameters affecting the optimum solution. The integration of a multitude of
issues within one system in a consistent manner, with measurable relationships
between the parameters, allows for fast engineering decision mading in a
workshop environment. Thus providing a means for the comparison, evaluation
and optimization of alternative layouts using common and consistent data. It also
maintains the ability to track changes made to the scenario models while
providing a complete history of the evolution of the field development.
Some of the disciplines involved in a field development are shown in Figure 1;
with a sketch of a simple generic field development scenario incorporating a
Floating Production, Storage and Offloading vessel (FPSO) shown in Figure 2.
Figure 1 Various Disciplines Involved in a Deepwater Development
Figure 2 Generic Schematic of a Simple Field Development
The FOCU$ system has two main components:
- The GIS System which is made up of the GIS front-end and the GIS Interface
- The Cost Model CAPEX, OPEX and economic indicates that are derived
GIS System Overview
- Integration of data within the system is achieved through the application of
Geographical Information System (GIS) technology.
- Layers of information for the field development are grouped as presented in
Figure 3. The grouping of data in such a manner provides the necessary
flexibility to investigate various scenarios.
- In the GIS, elements for each component in the field development are defined
through customized attributes for the elements.
- The dynamic ‘Hot-Linking’ of the field development components and the Cost
Model is achieved through the development of a GIS System Interface.
- The Logic for each element and its associated components is maintained
through the application of “Stick Diagrams”. A typical Stick Diagram is shown
in Figure 4.
- The logic presented in the Stick Diagrams identifies the connectivity between
elements.
- Approval of the logic in the Stick Diagrams from the various disciplines
achieves “Buy-In” from these groups and gives the system a common basis to
evaluate field development scenarios.
- The GIS and Cost Model adhere to the logic and assumptions made in the
Stick Diagrams and thus are highly project specific.
- On applying the logic, the data given by each discipline is imported into the
system and ownership of the data is recorded.
Figure 3 Representative layers of Information and Database Elements
Figure 4 Stick Diagram of a Typical Daisy Chained Water or Gas Injection Flowline System
