The Use of Expandable Sand-Control Technology as a Step Change for Multiple-Zone SMART Well Completion - A Case Study

Abstract

The Champion West (CW) field Offshore Brunei, North Borneo consists of alarge number of vertically stacked hydrocarbon bearing reservoirs where thinlayers of laterally continuous shales are sealing the different hydrocarboncolumns. Wells in CW are typically completed selectively on multiple reservoirs (3–5zones) due to contrasting reservoir pressures and fluid properties and forreservoir management purposes. Although the reservoir rock is relativelyconsolidated, sand exclusion has been installed on shallower reservoirsfollowing sand failure in offset wells. Internal Gravel Packing (IGP) has inthe past been the preferred sand exclusion technique. Due to a high deviation in the four CW Early Oil Development (EOD) wells(54–66 deg.), it was desired to incorporate remote operated smart wellequipment to minimise future well intervention requirements. As the large distance between zones would require up to four IGP operationsper well (resulting in high costs) and would not provide sufficientthrough-bore to install the smart well equipment, it was decided to useExpandable Sand Screens (ESS) for sand control purposes in the new wells. Theuse of ESS facilitates multiple zones to be completed in single installationswhilst providing a larger through-bore for the installation of smart wellequipment. The paper discusses the sand-face completion design and installationaspects. As one of the EOD wells was completed with IGP, a benchmarking (rigtime, cost, performance) of the ESS technique is also presented. Finally, recommendations are made which should enable further cost reductions in thefuture. Introduction Champion West is situated 7 km N-NW of the Champion Main field offshoreBrunei. The field was discovered and put on production in 1975. By end 2000, some 16 wells have been drilled of which 10 are producers. An appraisal welldrilled in 1997 proved up new oil volumes and based on the results, an EarlyOil Development drilling campaign, consisting of four wells (CW-12/13/14/15), was executed during January - June 2000 to target undeveloped reserves andappraise new reservoirs. Operational Summary The CW EOD wells were drilled and completed in batch mode from splitterwellheads on an offshore well jacket. Drilling and completion details arepresented in Table 1. Each well was perforated on 3–5 zones using 4.5" TCPHSD guns under 5000 kPa drawdown. Big hole (RDX charges, 12 spf) were usedwhere sand control (ESS or IGP) was required to maximise the area open to flow.Sand control was installed and the wells were completed as single selectivemulti-zone producers using smart well technology (mini-hydraulic inflow controlvalves and permanent gauges) for reservoir management purposes and to minimisefuture well intervention requirements.

A review of experimental studies on sand screen selection for unconsolidated sandstone reservoirs

“…These are poorly consolidated sandstone reservoirs, and many of the wells have experienced sand production. To mitigate the impact of sand production, many wells were completed with internal gravel packing as the preferred method of sand control (Fourie et al 2013;Saeby et al 2001).…”

“…ESS was considered as a good alternative to gravel packing because of the lower cost, the ease of operation, logistic simplicity and completion flexibility. ESS could expand to eliminate the annulus and make gravel packing operations unnecessary in reservoirs with reactive shale, low fracture gradient, or fractures and faults (Saeby et al 2001;Lau et al 2004).…”

“…Due to the declining oil price, the main reason for using STC-SAS was that it could reduce the rig completions time by about 50% compared to the conventional multiple trip SAS completions, hence saving operation costs. • Openhole gravel packs (OHGPs) with a predrilled liner have been successfully installed in 4 wells in the Raven field as reported in Tahirov et al (2019). Raven field is located in Egypt and is high-pressure high-temperature (HPHT) gas field with a reservoir pressure of over 10,700 psi and reservoir temperature around 141 °C (285 °F).…”

Optimization of Well Performance in a Selective Subsea Sand-Control Completion, Offshore Nigeria

“…GPs were identified as a reliable sand-control technique. Saeby et al (2001), also dealing with stacked and compartmentalized reservoirs in Brunei, estimated between 2.5 and 3 rig days per GP, while ESS deployment would roughly take 2.5 days, regardless of the number of zones being completed. The information gathered internationally as well as from other operators in Nigeria by the well engineering staff showed • Cased-hole GP and cased-hole ESS would give (on average) similar well-productivity results.…”