Why Use Zeta?

Well interventions with coiled tubing, snubbing, slickline or wireline are becoming more challenging due to increased well complexity, more sophisticated applications, higher wellhead pressures, deeper wells, and floating structures with independently moving wellheads. These challenges often require a taller, higher pressure, intervention stack with less stability than classic intervention stacks. These conditions can impart significantly increased stress levels on the well intervention stack.

Anecdotal evidence indicates that four or five catastrophic stack failures occur each year. Many more “near miss” events occur in which some component of the intervention stack is bent but doesn’t fail. Stack failures result in additional costs due to unproductive time. Failures also provide a situation that could involve bodily  injury and unplanned release of well pressure.

Historically, there has been a lack of tools to accurately model and monitor these intervention stacks. Swaying of the stack can often be observed as a result of wellhead, or floating platform movement. Stack movement is routinely observed on risers supported by a crane, due to the limited lateral support provided by the crane and guy wires. Knowing how much sway is within safe operating limits, when more supports are needed, when to halt operations due to safety concerns as a result of changing job conditions, and the selection of the proper intervention equipment has depended upon the experience of the personnel responsible for the field operation.

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