The Whipstock

The whipstock is a steel ramp shaped device which deflects the bit off the cement plug. Two types are popular. One is called a permanent whipstock because it is cemented and left in the hole. The other is called a retrievable because after deflecting the bit off the cement plug it is pulled from the hole. The basic problems which often occur are similar for both types. The first problem is that the whipstock is not set on bottom which allows the bit to drill around the end of the whipstock and back into the old hole. This problem is usually caused by bottom fill which was not removed before setting the whipstock. The whipstock is set on the bottom of the hole with exacting precision measurements of the setting string and drilling string to which the setting string must be matched. After pulling out of the pilot hole, the whipstock may turn which prevents the re-entry into the pilot hole. The rock may be of sufficient strength that the drill bit will cut through the steel of the whipstock rather than the surrounding rock.

The procedure for running an open hole cemented whipstock for the purpose of sidetracking without azimuth orientation is the following.

set the

  1. Set a cement plug
  2. Run the whipstock in the hole
  3. With precision measurements whipstock on bottom
  4. Cement the whipstock in place
  5. Drill off the whipstock

The procedure for setting a retrievable whipstock is

  1. Set a cement plug
  2. Run the whipstock into the hole with a small diameter bit
  3. Set the whipstock on bottom
  4. Shear the pin which connects the whipstock to the drilling string
  5. Drill 10 feet of pilot hole with the bit
  6. Pull the small bit and the whipstock
  7. Run in the hole with a full size bit and a knuckle joint
  8. Drill to about 30 feet
  9. Pull the knuckle joint and bit
  10. Run a full size bit and a drilling BHA

Sidetracking from a window within casing with a whipstock may be less expensive and faster in some cases. After the window is cut, a whipstock fastened to a hanger is run into the hole and the hanger is set within the casing below the window. The hanger locks the whipstock in place with the assurance of the casing. A cement plug is not required.

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Homeowners Guide To Landscaping

Homeowners Guide To Landscaping

How would you like to save a ton of money and increase the value of your home by as much as thirty percent! If your homes landscape is designed properly it will be a source of enjoyment for your entire family, it will enhance your community and add to the resale value of your property. Landscape design involves much more than placing trees, shrubs and other plants on the property. It is an art which deals with conscious arrangement or organization of outdoor space for human satisfaction and enjoyment.

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