When is wellhead installed

The wear bushing is then lowered through the BOP system until located in the casing head bowl. The wear bushing is locked in place, either by lockdown pins in the casing head housing flange or by lockdown pins located in a lockdown flange. The running tool is then removed and the drilling operation can resume.

After the hole has been drilled for the intermediate string, the casing is run in the hole and cemented in place. The intermediate string is cemented to a predetermined depth to ensure a good cement bond is obtained between the surface casing and the intermediate casing. A cement plug is left in the intermediate casing, just as it was in the surface casing. The casing is then suspended from the elevators at the rig floor, and the casing hanger is installed either through the BOP system or underneath the BOP system.

In this example the casing hanger will be installed underneath the BOP system. To begin, the BOP system is nippled down and picked up to a height approximately 3 feet. The casing hanger is then installed. Holes are cut in the casing to allow the drilling fluids to drain out of the casing riser. When the casing has drained, a rough cut is made and the balance of the casing riser is removed.

The BOP system is removed. The casing spool with a crossover seal is installed. The BOP system is nippled up and preparation is made to drill out for the production casing string. To test the BOP system the test plug is made up on the drill string and lowered through the BOP system, until properly located in the casing spool bowl.

The wear bushing is then lowered through the BOP system until located in the casing spool bowl. The wear bushing is locked in place either by lockdown pins and the casing spool flange or by lockdown pins located in a lockdown flange. The production casing string is generally run to the total depth of the well and is the casing string in which the production packer is installed.

When the hole is drilled and the production casing is run and cemented in place, the casing hanger is installed. The casing riser is drained. A rough cut is made and the BOP system removed.

The final cut is made to the production casing in preparation for installation of the tubing spool. The tubing spool with a crossover seal is installed in the same manner as the casing spool. After the tubing spool has been installed, the seals and connection are tested and the BOP system is nippled up. Preparations are now made to run production tubing in the hole. Production tubing is considered any pipe string 4 inches in diameter or less, though sometimes larger sizes of pipe are used.

When the plug has been drilled out and a cleanout trip completed, the perforating gun is run in the hole and the casing is perforated or shot. The downhole packer assembly is run and installed in the production casing. A packer is in essence a CO assembly that isolates the reservoir from all strings of pipe, except the production tubing.

New Wellhead Equipment for Old Oilfields. Burman, S. Mensa Project: Well Drilling and Completion. Cort, A. Dupal, K. Eaton, L. Gordy, C. Case History of a 22,ft Deepwater Wildcat. Hadj-Moussa, N. Harms, D. Heijnen, W. A New Wellhead Design Concept. Holand, P. Reliability of Deepwater Subsea Blowout Preventers. Huntoon II, G. Kenda, W. Landeck, C. McLeod, S.

Offshore Magazine. Nikravesh, M. Schulz, R. Tuah, J. Triple Wellhead Technology in Sarawak Operations. Watson, P. Wei, J. Help with editing Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. Publication Information. Petroleum Engineering Handbook Larry W. Lake, Editor-in-Chief.

Volume II - Drilling Engineering. Copyright , Society of Petroleum Engineers. Chapter 8 - Introduction to Wellhead Systems. Drilling a Well on Land When a well is drilled on land, an interface is required between the individual casing strings and the blowout preventer BOP stack.

This interface is required for four main reasons: To contain pressure through the interface with the BOP stack. To allow casing strings to be suspended so that no weight is transferred to the drilling rig. To allow seals to be made on the outside of each casing string to seal off the individual annulus. To provide annulus access to each intermediate casing string and the production casing string. We will address each of these points in turn and describe in more detail how this is achieved with the wellhead.

Pressure Containment When drilling a well on land, a spool wellhead system is traditionally used, as shown in Fig. Stream-Flo has over 50 years of history in the oil and gas industry. During that time, our extensively trained and experienced service and support technicians have installed our wellheads and other products around the world.

Our crews are trained in detailed running and test procedures to ensure efficient, cost-effective service without compromising safety. Our service fleet is equipped with a full line of soft parts and extras to support all service requirements.