World Longest Single-Trip Multizone Cased Hole Gravel Packing with Alternate Path Shunt Tubes | SLB

World Longest Single-Trip Multizone Cased Hole Gravel Packing with Alternate Path Shunt Tubes

Published: 03/08/2021

Schlumberger Oilfield Services

A multizone cased hole completion with a bottom hole assembly of world-record length at 2,600 ft was installed in Malaysia in November 2019 where three zones were simultaneously gravel packed in a single trip utilizing shunt tube technology. This sand control completion was successfully executed with a combination of sand control pumping and sand control tools, unconventionally performed by two different service providers.

The well consisted of three zones of interest approximately 1,000 ft apart. The bottomhole assembly was designed with two shunted cup packers for zonal isolation and shunted 12-gauge wire wrapped screens across each perforation. The shunts were left open ended below the cup packers, allowing the carrier fluid to exit the zone below with minimal friction. Downhole memory gauges were deployed along the washpipes for post job evaluation. Diligent lab testing was performed to select the carrier fluid, a clarified high-grade xanthan polymer with good 20/40 proppant suspension with less formation damage and acceptable dehydration to avoid bridging inside the shunts.

Detailed risk assessment that was performed during the planning stage focusing on interfaces, equipment limitations, expediting, and decision flow charts between the two service providers led to flawless execution at the wellsite. Compared with conventional stack-pack completion, significant time savings of approximately seven days was observed with this single-trip design; the concept of open-ended shunts below the cup packers replaced the majority of the shunted blank pipes with standard blank pipes, eliminating the time required to install jumper tubes. Good results were observed during the injectivity test in addition to the well already having losses of 20 bbl/h. Hence, no acidizing was required prior to the gravel-packing operation. Based on surface monitoring, there was clear indication of sequential packing from the top zone to the bottom-most zone via shunt tubes, followed by a final screenout. Findings were further verified after performing the downhole bottomhole gauge analysis using the retrieved data from the memory gauges. The well has been in production since December 2019.

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