| dc.description.abstract | Most of the energy used all over the world come from fossil fuel in which hydrocarbons which
are non-renewable sources of energy contribute in large percent. Recently most of oil fields are
tertiary phase of recovery. As a result, more techniques for improving the recovery of
hydrocarbons (oil) remained in the reservoir after primary and secondary recovery phases have
to be applied.
This work is based on reservoir simulation to improve the oil recovery of the Gullfaks field
(Statfjord I-1 segment) by applying various IOR methods including well placement optimization,
chemical injection based on surfactant, polymer and low salinity water flooding.
The simulation from the base case with three wells, two producers (C-16 and A-36) with one
injector (A-41), resulted into the recovery factor of 37.89% from May 1992 to January 2001.
When the production time was extended up to 2032, the base case attained a maximum recovery
factor of about 46.39%. Low salinity was applied as a secondary method to the base case, the
recovery factor was observed to increase from 37.89% to 40.10%.
New case with five wells (three producers and two injectors) was proposed, and the simulation
was performed up to 2035, oil recovery of about 64.79% was achieved which is significantly
improved compared to the base case.
Polymer and surfactant injection were implemented from the proposed case for a duration of 15
years, unfortunately a minor effect on the oil recovery was observed. The observed improvement
in the oil recovery factors were about 0.2% and 0.1% by surfactant and polymer injection
respectively. This alternative was therefore rejected, and the low salinity method which was
observed from the base case to provide improvement in the oil recovery was adapted.
Low salinity water flooding technique with various salt concentrations from 500ppm to
30000ppm were implemented as secondary and tertiary method. In all these cases significant
improvement in oil recovery was observed compared to waterflooding and other chemicals
applied . Based on simulation results of oil recovery, incremental oil and gas produced and NPV
analysis, low salinity waterflooding has been proposed as the best IOR method for Statfjord I-1
segment .
As part of recommendation further studies including other chemical injection such as alkaline
flooding, assisted surfactant polymer flooding (ASP), surfactant injection in salt water and other
methods with appropriate reservoir and fluid data from the respective field is very important. | |
