What is a cement head?

What is a cement head?

1. n. [Drilling] A device fitted to the top joint of a casing string to hold a cement plug before it is pumped down the casing during the cementing operation. In most operations, a bottom plug is launched before the spacer or cement slurry.

What is the purpose of cementing a well?

To maintain the integrity of the wellbore, the hydrostatic pressure exerted by the cement, drilling fluid, etc. must not exceed the fracture pressure of the weakest formation.

What is oilfield cementing?

Part of the process of preparing a well for further drilling, production or abandonment, cementing a well is the procedure of developing and pumping cement into place in a wellbore. Most commonly, cementing is used to permanently shut off water penetration into the well.

What are the main equipments used in well cementing?

Contents

  • Centralizers, Turbolizers and Scratchers.
  • Float Shoe.
  • Float Collar.
  • Stage Collar.
  • Cementing Plug.

Which cement is used in oil wells?

Oil-well cements are used for cementing work in the drilling of oil wells where they are subject to high temperatures and pressures. They usually consist of portland or pozzolanic cement (see below) with special organic retarders to prevent the cement from setting too quickly.

What is a cement squeeze job?

A remedial cementing operation designed to force cement into leak paths in wellbore tubulars. Squeeze cementing operations may be performed to repair poor primary cement jobs, isolate perforations, or repair damaged casing or liner. …

Why oil wells are cased and cemented?

Casing that is cemented in place aids the drilling process in several ways: Prevents contamination of fresh water well zones. Prevents unstable upper formations from caving in and sticking the drill string or forming large caverns.

Which class of cement is used in oil well?

The 3 most commonly API certified oil well cements are Class A, Class G, and Class H depending on the demanding well conditions. Classes G and H are used for deeper and high temperature and pressure well conditions.

What is remedial cementing?

1. n. [Well Workover and Intervention] Cementing operations performed to repair primary-cementing problems or to treat conditions arising after the wellbore has been constructed.

What is a float shoe in oil field?

1. n. [Well Completions] A rounded profile component attached to the downhole end of a casing string. An integral check valve in the float shoe prevents reverse flow, or U-tubing, of cement slurry from the annulus into the casing or flow of wellbore fluids into the casing string as it is run.

What is a float collar?

1. n. [Well Completions] A component installed near the bottom of the casing string on which cement plugs land during the primary cementing operation. It typically consists of a short length of casing fitted with a check valve.

What are the properties of oil well cement?

These properties are thickening time, compressive strength, slurry volume, free water separation, and hydraulic flow properties. The thickening time is the amount of time necessary for the slurry to reach a consistency of 100 poises at different well temperature, depth, and pressure conditions.