complation fluid -kill the well

Methods of well kill

killing the well

A well kill is the operation of placing a column of heavy fluid into a well bore in order to prevent the flow of reservoir fluids without the need for pressure control equipment at the surface. It works on the principle that the hydrostatic head of the "kill fluid" or "kill mud" will be enough to suppress the pressure of the formation fluids. Well kills may be planned in the case of advanced interventions such as workovers, or be contingency operations. The situation calling for a well kill will dictate the method taken.

Reverse circulation

Bullheading

Forward circulation

Lubricate and bleed

Capacity Formulas

Capacity of tubulars and open hole: drill pipe, drill collars, tubing,

casing, hole, and any cylindrical object

Annular capacity between casing or hole and drill pipe, tubing,

or casing

Annular capacity between casing and multiple strings of tubing

in haigh reservoir pressure you need addtives to kill the well

Requirement for kill weight brines

Many completion operations such as running the reservoir or upper complet

perforating, gravel packing and stimulation require a clean, clear fluid. In some

cases, this fluid also has to have sufficient density to exceed reservoir pressure

(i.e. a kill weight fluid) in order to prevent an influx

in order to prevent an influx.

Brine selection

The desirable properties for a completion fluid are

Brines should be clear and uncoloured

Low corrosivity

Environmentally acceptable

Compatible with any other fluids that might contact the completion fluid such as

control line fluids

Compatible with additives such as inhibitors, loss control material and viscosifiers.

Formation and reservoir fluid compatibility if the fluids could be lost to the

reservoir or an influx into the completion occurs.

Temperature stability.

The maximum density of a brine depends on the salts used, brine temperature

and to a lesser extent pressure

Common completion £uid brines with approximate maximum densities