Whipstock Pathbreaker Case Study for Oil and Gas

Case Study for PathBreaker™

The first-ever application of a PathBreaker™ Hydraulic Whipstock in Ukraine was spearheaded successfully by SPT for an Oil Company based in the west of Ukraine. This was made possible thanks to the recent partnership between SPT and its local distributor company, Goryzonty.

Whipstock used for casing size 5 ¾ inch (21.51 lb/ft).

Job profile

The client’s objective is to re-enter the reservoir. According to the engineering design, the casing window needs to be milled inside the 5 ¾ inch casing at 600m before drilling the 4 ¾ inch section. The geological target is located in the 180m vertical section. Total Depth was planned at 1450m. All operations were performed with a workover rig (50 t lifting capacity, 330 horsepower).

Main Challenges

During the execution of this job, there were three main challenges

CHALLENGE #1 - Perforation Zone

Be able to run the whipstock assembly through the perforation zone.

Challenge #2 - Dimensions

2 7/8in Drill pipe with ID 50mm. The available Gyro tool for the orientation has an OD of 49 mm. A clearance of 1 mm is too low to guaranty the passage of the Gyro tool.

CHallenge #3 - Survey Data

There was no prior survey data of the current well.

Solution

Prior to initiating the project, all the necessary and required planning was done. Field engineers in cooperation with the SPT technical team came up with a solution to overcome the above-mentioned challenges.

It was agreed to utilize a window and watermelon mill in drift run prior to the Whipstock being set. As was expected, the perforating intervals caused tight spots that were polished with the mill up to 600m. Tubing 2 7/8”(ID 62mm) instead of drill pipe was used to transport and orient the whipstock. This contributed to solving the issue with the Gyro tool passage. SPT designed a fit for purpose shear pin with a low shear load so as to not exceed the tubing maximum strength capacity.

When the Whipstock assembly reached the desired depth, the following operations were performed

Run casing collar locator inside the tubing to define the depth of the casing collar.
Well surveying with GyroTracer HT.
Orienting of Whipstock with GyroTracer HT.
Establish reverse circulation
Hydraulic anchor activating
Shear transport pin
POOH tubing and running gear
Makeup milling assembly and RIH
Casing window milling

10 hrs

MILLING of Casing

100 m

TRUE DEPTH

30 hrs

Complete Operation

Result

Good engineering planning prior to the job and the high quality of the PathBreaker™ Hydraulic Whipstock system overcame all of the operational challenges during the project execution stage, resulting in which the sidetrack operation was performed successfully.

SPT and the Ukrainian distributor demonstrated that good communication and planning between supplier and service provider plays a key role in excellent service delivery and a successful project.