DepthLOG - Alaska | Schlumberger
Case Study
Location
United States, North America, Offshore
Details

Well characteristics

  • 4 1/2„2-in. liner
  • 88° deviation
  • No oil production
  • 1-in. cementer port open

Job highlights

  • Real-time correlation with baseline log
  • Tubing patch placed in 8-ft window
  • Success confirmed by subsequent log

DepthLOG - Alaska

Precise depth correlation enables placement of tubing patch within 8-ft window

A new well that produced only gas and hydrates after two flowing attempts required intervention. The suspected problems were damage in the horizontal section and gas leakage through an unclosed 1-in. cementer port in the 41⁄2-in. liner at 10,650 ft. Cleanup of the horizontal section and return of the well to production required isolating the orifice with a tubing patch.

DepthLOG - Precise depth correlation enables placement of tubing patch within 8-ft window

The job design required setting a bottom packer in a pup joint below the leaking port and a top packer in a solid joint above. Given the temperature, tubing size, and estimated buckling and stretch, the use of memory correlation and flagging pipe for depth cor-relation would not have been accurate enough for tubing patch placement. The DepthLOG* service provided real-time depth correlation to accurately place the tubing patch within an 8-ft window. The overall bot-tomhole assembly (BHA) length extended 45 ft, and the borehole deviated 88º in the setting window.

Unlike other conventional casing collar locator (CCL) systems, the DepthLOG service does not require data cable. Communication takes place via pressure telemetry signals, and a real-time CCL log is available at surface. Because balls and fluid are allowed to pass through the tool, a standard ball-operated firing head can be used. Using the real-time data on the surface CCL log, specialists were able to correlate depth with the baseline log, accurately position the BHA, and set thepackers on depth.

A subsequent log, along with 1,300-BOPD production, verified the succes

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