OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 37 Oil and Gas Wells

Section 782 Well stimulation

Subsections 782(1) and 782(2)

Stimulation is a treatment to restore or enhance the productivity of a well. Treatments are either hydraulic fracturing treatments or matrix treatments.

Fracturing involves pumping specially engineered fluids at high pressure and at a high rate into the formation, causing a fracture to open. Proppant, such as grains of sand, is mixed with the treatment fluid to keep the fracture open.

Matrix stimulation includes acid, solvent or other chemical treatments to improve or restore the permeability of the formation.

Remedial cementing is performed to repair primary-cementing problems or to treat conditions arising after the well bore has been constructed. This process is carried out at the time of well completion.

Subsection 782(3)

Even if the piping system is restrained in accordance with section 188, no worker is permitted in the danger area unless the pump pressurizing the system is disengaged.

Subsection 782(4)

If liquid carbon dioxide or liquid hydrogen escapes into the atmosphere, it rapidly vapourizes creating a low-temperature hazard and an oxygen-displacement hazard. This subsection addresses that hazard by requiring pump operators to be on the side of the pumping unit away from the discharge line.

Should pressure be lost in the piping system, a check valve near the well head would act to prevent the return of fluids from the well head which could contain hydrocarbon vapours.

In addition to providing fire protection equipment, the following preventive measures should be considered:

(a) all blending equipment be grounded;
(b) all equipment unloading sand be bonded to the blending equipment;
(c) pressurized suction lines be covered so as to deflect fluids in case of leaks;
(d) lines not be laid under vehicles;
(e) any flammable fluids spilled be cleaned up before pumping begins; and
(f) all sources of ignition not necessary for the job be shut down.

The hosing used for a mud line is typically not rated for pressure service and therefore, should not be used.