CHALLENGE
Improve rig efficiency during completion operations, remove perforation burrs to mitigate packer issues, and perform isolation and injectivity tests with exposed open hole below the casing.
SOLUTION
Modify the tubing-conveyed perforating (TCP) gun string for one-trip efficiency to incorporate a casing scraper to remove the burrs and avoid packer damage, valves to manage pressure at the firing head, and a packer positioned relative to the guns as required for the job.
RESULTS
Designed string and ran many times in different environments with great success.
“This combination of techniques saves us at least one day of rig time in each well completion. This is a large amount of savings for the company.”
Operator
Perforating project
Identifying opportunities for TCP efficiency
An operator has an ongoing program drilling development wells that are cased and perforated. Many of these wells require isolation tests, injectivity tests, and acid matrix stimulation as part of the completion process prior to running dual completions. Typically, this involves perforating two zones, running a scraper to remove the burrs caused by perforating, and then running a packer and valve assembly to conduct the various tests required.
While this older technique is effective, it requires several trips into the well with drillpipe, which is time consuming and uses a lot of expensive rig time.
Streamlining well operations
The operator and Schlumberger worked together to improve operational effectiveness and efficiency.
The TCP system was improved by incorporating a casing scraper, packer, tubing valves, and multiple guns to perforate separate zones at the same time. Guns were spaced to accommodate multizone tests in a single run, and pressure-actuated valves isolated the firing head from open perforations as well as to facilitate acid placement. After perforating, the entire string is moved up or down hole to place the packer as required to conduct the rest of the program.
The successful use of various gun and running string assemblies is regularly saving at least one trip in the well with drillpipe. Key to the success of these streamlined operations is close collaboration between the operator’s drilling team and Schlumberger perforating experts during the planning phase of the well.
Basic TCP string.

Improving operational efficiencies through collaboration
A well with an openhole section at the bottom needed to be perforated and then an injectivity test conducted to ensure that the zone would take acid. To achieve this, TCP guns were run with a weightset packer on the bottom of the guns. The interval was shot and then the packer was set to allow the injectivity test to be completed. A casing scraper was positioned above the packer to clean the perforation burrs on the way out of the well. This configuration saved two trips in the well with pipe.
In another well, a test to confirm isolation between two sets of perforations was required prior to running a dual completion. The TCP guns were configured to shoot both intervals at the same time. After shooting, the packer incorporated in the string between the guns was set and the isolation test conducted.
A casing scraper was installed above the packer to scrape the casing on the way out of the well with the gun and packer assembly. This saved a run on pipe.
Close cooperation between the operator and Schlumberger has led to the adoption of a flexible operating procedure using innovative approaches and equipment combinations to improve job efficiency and perforation performance in these wells. More than 30 of the operator’s wells have been perforated with
TCP in various configurations to improve the overall operational efficiency.
*Mark of Schlumberger
Other company, product, and service names are the properties of their respective owners.
Copyright © 2014 Schlumberger. All rights reserved. 14-TS-0057