WAB® enables efficient evaluation of exploration wells

Challenge
Well construction & integrity
Sub Standard Graphics 3D JIDN154399 00000
  • Well type Oil producer
  • Reservoir type Carbonate
  • Enhanced zonal isolation And cement assurance via 4 x WAB in open hole
  • Wab rotational capability Significantly enhanced primary cementing operation
  • Positive DST results Validate commercial viability of reservoir
  • Gas tight wab Set in 13 3/8” for V0 protection of liner hanger
  • Short term delivery Facilitated by Welltec manufacturing capacity
  • Location Asia Pacific

Background

Two 1214 WABs were the first of two production wells (gas & oil) with a further potential of seven wells.

This Welltec® Annular Barrier (WAB) value is derived through ensuring pressure isolation of several potential production zones to be Drill Stem Tested (DST), behind the 9 5/8” casing (80° deviation).

Operation

The 9 5/8” casing was run with two 1214 WAB positioned to isolate the zone. The cement was pumped and on bumping the plug, the WABs expanded quickly under surface control.

The cementing challenge was exasperated by the depleted zones within the 12 ¼” section and the high angle long length hole. The WABs enabled liner rotation both during deployment and cementing along with providing centralization and anchoring once expanded.

The 8 ½” hole was drilled and a slotted 5 ½” liner completion installed with an Isolation valve to isolate the lower completion.

The 9 5/8” zones were selectively perforated with Tubing Conveyed Perforating (TCP) guns. The first lower zone produced water and was plugged off shallow with a retrievable bridge plug. Subsequent zones were perforated and tested positively. The zone acid stimulated to improve productivity during the DST tests.

Finally, the upper completion was installed.

Second operation

Second of two production wells (gas & oil) with a further potential of seven wells in 2018. This WAB solution delivers pressure isolation of three potential production zones behind the 9 5/8” casing (80° deviation). Each zone relatively short in True Vertical Depth (TVD) with a potential oil water contact below.

The 9 5/8” casing was run with four 1214 WAB positioned across the 12 ¼’ open hole to isolate the 3 zones across the reservoir section and an additional 1214WAB set within the 13 3/8” casing for B annulus Sustained Casing Pressure (SCP) protection. On bumping the cement plug, all five WABs expanded.

The cementing challenge was exasperated by the depleted zones across the 12 ¼” section along with the high hole angle. The WABs enabled liner rotation during the casing deployment and during the cementing operation, along with casing centralization and anchoring once expanded

The 8 ½” hole was then drilled and a slotted 5 ½” liner completion installed with an isolation valve to isolate the lower completion.

The 9 5/8” zones were perforated with TCP guns and a DST string run and the zone flow tested.

Finally, the upper completion was installed.

Welltec

Zonal isolation assurance via WAB provides tangible DST result to confirm reservoir viability.

Challenge
Well construction & integrity
1036X518 Jidn154399 1214 Wab To Isolate Potential Reservoirs For Dst 00000 Min