Abstract
Saqqara is a very challenging field in the Gulf of Suez in the Red Sea area, producing from the deep sandstone Jurassic formation. This formation can sometimes be watered out, with a combination of high H2S and CO2 levels in the production. High sand quality has developed high horizontal and vertical permeability, which challenges any water shutoff treatment placement.
One of the critical measures of success in water shutoff treatments is selective zonal shutoff across an existing hydrocarbon zone. It was challenging to select a deep penetration polymer to treat the selected zones, as it must resist high temperature degradation (321°F), particularly in existence of high concentrations of H2S. Different water shutoff (WSO) treatments were considered, but selecting an organic crosslinked polymer (OCP) gave the best lab results because of its stability in high temperature conditions.
Placement and isolation techniques were challenging, particularly with the existence of multiple zones of interest. Therefore, coiled tubing (CT) well intervention methods were selected for best placement without resorting to a more expensive workover option.
The results of the treatment were designed toward the sustainable production of these kinds of mature watered out fields. The treatment succeeded by reducing produced water from almost 2,300 BWPD down to almost zero BWPD.
This process allows the operator to increase the drawdown value, which strongly affects the BOPD value compared to the initial watered-out condition. The treatment maximized the value from mature fields revitalization, redevelopment, and end of field life planning.
