ABSTRACT
Reservoir development planning and well placement significantly
affect hydrocarbon recovery. Therefore, strategic well placement and
development techniques are essential to minimize the risk of
unproductive drilling and also to maximize production within the
reservoir.
This study presents an approach to well placement and production in a
green field. A 3D static model of the green field was built using
geostatistical techniques to distribute the various model petrophysical
properties such as porosity, thickness, and permeability in order to
provide reliable reservoir description for dynamic modeling. A dynamic
model was constructed to evaluate various reservoir development
problems, including well placement, number and types of wells to be
drilled in the green field. The drilling of both vertical and horizontal
wells was considered in the analysis. Finding the optimal length of the
horizontal well to be drilled in order to maximize oil recovery and to
properly develop the reservoir was considered a significant problem to
address. A sensitivity analysis was carried out to evaluate the impact
of horizontal well length on oil recovery. The vertical to horizontal
permeability anisotropy (kvkh) was also studied in this work.
The results of the analysis indicate that horizontal well length
influences cumulative oil production. Drilling a 3000ft. long horizontal
well was found to produce a higher cumulative volume of oil than the
oil recovery obtained from similarly placed horizontal wells but with
shorter lengths of 2000 ft. and 1500 ft.
It is concluded that the methodology proposed in this study will find application in the development of a green field.
Keywords: Reservoir development, well placement,
simulation, petrophysical propertydistribution, geostatistics,
permeability, porosity, thickness
CHAPTER 1
INTRODUCTION
1.1 Statement of Problem
Reservoir development and well placement have been one of the
existing challenges in the petroleum industry over the years. This is
because different engineering, geological and economic variables
affecting reservoir performance are practically involved.
More importantly, the decision on how to increase oil recovery and
maximize the economic profitability of field development projects is the
pivot point. Therefore, an extensive evaluation of certain decision
variables such as reservoir properties, production scheduling
parameters, type of well, location to drill new wells and an effective
technique to obtain the best economic strategies are required. Also,
consideration should be given to the spatial distribution of geological
and rock properties such as porosity and permeability in order to locate
potential hydrocarbon zones for drilling activities. This involves
critical evaluation of development strategies to produce the greatest
amount of hydrocarbons within the physical and expected economic limits.
Several techniques have been adopted to achieve efficient reservoir
development process which significantly affects the productivity and
economic benefits of an oil reservoir. However, the aim of this work is
to evaluate the impact of well placement on cumulative oil recovery
during the development of a green field.
In this study, reservoir simulation and spatial based modeling
approaches will be used as key evaluating elements for the development
of the greenfield oil reservoir to improve its productivity.
1.2 Objectives
The objectives of this study are to:
· Use geostatistical methods to distribute the petrophysical properties in building a 3D static model of the reservoir;
· Find the optimum number, type, and placement of wells required to develop the greenfield.
1.3 Methodology
The methods to be used include;
· Build a 3D static model of the green field by
o Digitization of structural and isopach maps of the A-1 reservoir
o Estimation and distribution of Porosity, Permeability, and Thickness at all
locations in the reservoir
o Estimation of Original Oil in Place (STOOIP)
· Construction of a 3D dynamic reservoir model
· Use of the 3D dynamic model to find the optimum number, type, and placement of wells to develop the reservoir.
1.4 Facilities and Resources
The facilities and resources used for this project include;
· AUST library and internet facilities
· Technical and academic expertise of supervisor
· Structure and Isopach maps of A-1 reservoir
· Isopermeability map of A-1 reservoir
· Isoporosity map of A-1 reservoir
· Computer software programs such as: GIS, SGeMS, Sensor Simulator
1.5 Organization of Report
This report is organized into five chapters. Chapter one is the
introductory chapter giving general information about the entire
project. Chapter two gives in-depth information of the study area and
reviews relevant literature related to this work. Chapter three places
emphasis on data.