Well Suspension Basics
What is well suspension?
A well suspension is the operation taken to isolate fluids in the wellbore while providing a means to easily produce or workover the well in the future. Operators will choose to suspend a well over abandon the well because it is usually much cheaper and still gives you the option to keep the well for observational, optimizing, injecting/disposal or re-completing purposes. Wells can be downhole abandoned but left in a “suspended” state so that the operator does not have to complete surface abandonment and reclamation at that time
How are wells suspended?
There are a variety of ways to suspend wells and which method you choose usually depends on the well type. The wells are assigned “risks” based on their completions, production, and composition of producing fluids. For example, critical sour wells are suspended in a way to ensure that sour gas cannot leak and pose a threat to health, safety and the environment (one method is a bridge plug capped with cement over the producing or injecting zone). A low risk gas well on the other hand, could be suspended simply by shutting in the wellhead and chaining up the wellhead valves. When a well is suspended it is usually subject to pressure tests. Depending on the suspension method used as well as the well type, pressure tests can be of either the wellbore or wellhead seals. Pressure testing frequency ranges from 1 to 5 years. Regulatory bodies may force the remediation of any wellbore issues even if the wellbore was suspended properly depending on the threat level of the wellbore issues.