Two Different Water Shutoff Applications in a Poorly Consolidated Sandstone Reservoir with Strong Waterdrive

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper describes the design, operation and results of two different water shut-off applications in a field located in Southern Venezuela. The production mechanism of the main reservoirs of the studied field is strong water drive. The presence of the active aquifer, the geological complexity and the high drawdown produced by the electric submersible pumps, it has abruptly increased the water-oil ratio causing premature shutting. The limitations of the traditional water shut-off applications in this field are the slotted liners gravel pack completion of the wells, the high formation permeability and the presence of caverns in the near wellbore due to sand production. A project was proposed to evaluate the gel technology, including the diagnosis of the high water production source and the design of applications to overcome these limitations. Two mayor causes were detected, water channeling through high permeability strakes at the top of the reservoir where thin shale barriers are present; and rapid coning at the base, where the sand has a higher vertical permeability and the water-oil contact is present. According to this, two different applications were designed and successfully evaluated in three wells of the field, two of them correctives and the other preventive. Relevant aspects of the design are the use of an elastic gel system of high consistency with easily controlled gelling times; and the use of placement techniques to guarantee the seal of offensive zones and the protection of the productive ones. In the corrective treatments the gelant was injected using mechanical isolation and the total volume was pumped in two batches, while dual injection was carried out in the preventive application. A reduction of 3000 barrels per day of water production was obtained, as well as a substantial increase in the productive life of the three wells.

Evaluación y experiencias en el control de conificación en pozos con alto corte de agua en yacimientos con empuje hidráulico

“…Por ser condiciones muy específicas, la probabilidad de éxito del uso de tratamientos químicos para la corrección y el control de la conificación de agua en pozos productores ha sido muy baja. Recientes casos históricos se reportan exitosos y proveen lecciones aprendidas en base al uso de tratamientos químicos para el control de la conificación de agua en pozos productores (Hunter, Soetedja, Rinadi, Mitchell & Gauntt, 1999), (Prado et al, 2005), (Thomas, Shtepani, Marosi, & Bennion, 2002), (Vega, Campomenosi, Hernández, Moglia & Peltier, 2018). Por lo tanto y basados en dichas experiencias de tratamientos químicos (p.e.…”

Lessons Learned from Four Selective Water Shutoff Treatments in Mature Reservoirs in Maracaibo Lake

“…Additionally, an elastic gel system with medium consistency was selected because of the presence of oil remaining in the layer. This type of gel system has shown DPR effect in several displacement test in berea and sandstone cores [6][7] , so the propose of use it was to cause the minimum reduction to the relative oil permeability in the invaded zone. In September 1997, as shown in fig.…”

“…Previous laboratories studies performed in PDVSA INTEVEP [6][7] demonstrated that an increase in gel consistency allows to increase the RRF values, therefore it was decided to evaluate a reduced volume of a high consistency gelling system in this application. According to this, a gel volume of 150 Bls equivalent to 5 ft of radial penetration was injected to the intervals 8820'-8832' and 8837'-8860'.…”

Research and Advances of Silicate Plugging Agent in the Oilfields

“…We have used polymer pre-crosslinking swell particle and fibrous pre-crosslinking swell particle in high-temperature and high-salinity reservoirs [1] [2] [3] [4] [5], but the sealing ability is bad. May the problem above mentioned can be resolved by means of the developing the inorganic blocking agent.…”