Environmentally Friendly and Economic Waterflood System for October Field at Gulf Of Suez, Egypt

摘要

October field is one of the major fields in GOS Egypt operating at 100,000 BFPD using 185 MMSCF gas lift injection gas though 50 active producing wells and 11 injection wells with 2 water source wells. Most of the resrvoirs are waterflood. October field is located 21 miles from the west shoreline in the Gulf of Suez. With time, the performance of the producing wells showed a significant decline in productivity which was attributed to reservoir pressure decline. So, a study was done and resulted in selecting a waterflooding technique for reservoir pressure maintenance and increase of the oil recovery factor. The economic success of a waterflood project depends on the additional oil recovery it can achieve relative to increased cost over primary development. it must aso be operated in an environmentally friendly manner. The water source chosen for a waterflood project is usually based on a number of different factors, such as scaling tendency, rock/fluid compatibility, and possibility of bacterial activity. It is possible that a combination of sources could eventually be used. At the location of the waterflood project there may be a number of alternative water sources such as, seawater and separated formation water. Water taken from the sea and separated water associated with produced oil generally need extensive chemical treatment and expensive facilities. Would the project still give this added cost? The October field waterflood uses a pure water productive zone for source water, which is then injected into the reservoir by two methods: 1- Water is produced from Zeit formation at depth 3000 ft by ESP and injected directly into water injection wells located on several adjacent platforms, without any chemical treatment. This was possible because the two waters (formation and injection water) were found to be compatible. 2- Dumping water from the Zeit source formation directly to the oil productive zone in the same wellbore by pressure difference, otherwise known as dump flooding. This technique has an economic advantage over conventional injection schemes by eliminating the need for source water treatment, since the provided water was found to becompatible with flooded reservoir water, formation clays, and rock matrix. It is significantly reduces facility and flow line requirements and saves deck space offshore, and also reduces environmently impact.