The need to re-develop one of the Brown fields located in the Niger
Delta area of Nigeria was necessitated by the fact that there are still
three undeveloped reservoirs in the field.
A total of six stacked reservoirs, A100 to A600 (all oil bearing with
associated gas) were penetrated between 8552 ftss and 10652 ftss by
APV-1 well. Reservoir blocks A200 and A600 are the largest in the field
accounting for 77% of the total field STOIIP. The well was completed
with a Two String Multiple (TSM) on the two levels, with the short
string producing from the A200 reservoir and the long string producing
from the deeper A600 reservoir, A300 behind the sleeve.
The purpose of this research is to identify the best developmental
plan to produce the reservoirs, either with a TSM completion or with a
Smart well completion based on the economics. There are many single well
fields in the Niger Delta area of Nigeria that have not been optimally
produced, hence this study seeks to maximize the life of this field.
The reservoirs were simulated and production forecast carried out amounted to 14.55 MMstb for a period of 16 years.
After economic analysis was performed, the Net Present Value for the
TSM and the Smart well completion were US $MM 241.9 and 248.88
respectively and an Internal Rate of Return of 155% and 202%
respectively, hence the Smart well development plan is recommended.
Petroleum reserves are declining, and fewer noteworthy discoveries
have been made in recent years (Abdus, 1990). The need to increase
recovery from the vast amount of remaining oil and to compete globally
require healthier reservoir management practices (Abdus et al, 1994).
However, technological developments in all areas of petroleum
exploration and exploitation, along with fast increasing computing
power, are providing the tools to better develop and manage reservoirs
to maximize economic recovery of hydrocarbons (Abdus, 1990).
A reservoir's life begins with exploration, which leads to discovery;
reservoir delineation; field development; production by primary,
secondary and tertiary means; and abandonment (Figure. 1.1).
Sound reservoir management is the key to successful operation of the
reservoir throughout its entire life. It is a continuous course, unlike
how the baton is passed in traditional E&P organizations (Abdus et
Reservoir Management is all about excellence in the Operate phase of
an E&P project life cycle. This is the only phase (Operate) that
earns income, to provide the return on investment and it is the longest
of the four (4) E & P business phases (Exploration, Appraisal,
Development and Operate) spanning decades. (Shell WRM Operational
Complete reservoir management requires the use of both human and
technological resources for maximizing profits (Abdus et al,
1994). It requires good coordination of geologists,
geophysicists, production, and petroleum engineers to advance
petroleum exploration, development, and production. Also, technological
advances and computer tools can facilitate better reservoir management
as well as enhance economic recovery of hydrocarbons. Even a 11 small
percent increase in recovery efficiency could amount to significant
additional recovery and profit. These incentives and challenges provide
the motivation to sound reservoir management. Reservoir simulation is
the way by which one uses a numerical model of the geological and
petrophysical characteristics of a hydrocarbon reservoir to analyze and
predict fluid behavior in the reservoir over time. In its simple form, a
reservoir simulation model is made up of three parts: (i) a geological
model in the form of a volumetric grid with face properties that
describes the given porous rock formation; (ii) a flow model that
defines how fluids flow in a porous medium, typically given as a set of
partial differential equations expressing conservation of mass or
volumes together with suitable closure relations; and (iii) a well model
that describes the flow in and out of the reservoir, including a model
for flow within the well bore and any coupling to flow control devices
or surface facilities (Lie, 1994).