ABSTRACT
A rise in the shallow unconfined groundwater level at the Booster Station 140 (BS-140) in the Burgan oil field of the Kuwait Oil Company (KOC) is causing water logging of the underground facilities in the station. Currently, the depth to the water is not more than 2 m from the ground surface within the perimeter of the booster station. Realizing this problem, the Research and Technology Group of KOC approached the Hydrology Department of the Water Resources Division at the Kuwait Institute for Scientific Research (KISR) to conduct a study in order to identify the source of the water that is causing the rise and to develop an implementation and operation plan of the dewatering system.
Utilizing geologic input from the field investigations and the available hydrogeologic data, a three-dimensional, finite element groundwater flow model that simulated the ground-water flow system in the area surrounding and within BS-140 was developed and calibrated. The development of the conceptual hydrogeologic model for the area under investigation and construction and calibration of the groundwater flow numerical model were based on the following information and data: (1) site setting of BS-140 and its spatial relationship to important features in the vicinity and the geologic framework of the area around BS-140; (2) records of rainfall and groundwater levels; (3) topographic data on a regular grid covering a total area of 25 km2; (4) water levels and water chemistry data from borehole census within approximately a 2.9-km radius of BS-140; (5) chemistry data for water and soil samples; and (6) drawdown in a series of monitoring wells during the pumping tests that were conducted within the scope of the study to investigate the hydraulic characteristics of the area. The groundwater model developed for this investigation utilized the numerical code MODFLOW, which solved the three-dimensional groundwater flow problems with an unconfined surface using the finite element method. The calibrated and validated model was then used to predict the dewatering requirements for managing the water table rise around BS-140 and the potential drawdown in the water table induced by this dewatering. It was recommended to pump from four production wells at a rate of 1501/min per well, to draw the water table down to an average depth of 4.5 m under BS-140. It was recommended that the pumped water could be utilized by KOC for several purposes depending on the level of treatment.
