Master of Science in Petroleum Engineering (MSPE)
The constant bottom-hole pressure method of managed pressure drilling is generally expected to reduce well control risks and apply well understood concepts when a kick is taken. Nevertheless, complications, such as operator error, leaks, plugging, equipment failures, and exceeding kick tolerance, can occur during kick circulation. By not properly interpreting the symptoms of a complication, a driller risks the consequences of additional influx, lost circulation or the simultaneous occurrence of both. To address the challenge of diagnosing complications, the implied pit gain (IPG) method is being evaluated as an enhancement to established industry practices. Traditional diagnostic methods attempt to match qualitative assessments of changes in the behavior of surface pressures, e.g. pump pressure and choke pressure, to particular complications. Under these circumstances, the interpretation of the onset of a complication may be subjective in nature and vary between individuals. By only evaluating changes in surface pressure, rig personnel may not be informed of the consequences of a given complication. Finally, previously published diagnostic strategies do not incorporate a structured approach for determining when kick tolerance has been exceeded. IPG is based on the concept that changes in surface pressures can be quantitatively linked to changes in pit gain with reasonable accuracy throughout the duration of a complication-free kick circulation. As a result, when these surface indicators deviate from a range of predicted behavior, one can objectively conclude that a complication is occurring. Research has been performed to demonstrate that the profile of the surface indicators, when deviating from predicted trends, contain unique attributes that can facilitate the diagnosis of a complication. Furthermore, quantifying the relationship between changes in surface pressure and pit gain over time provides data that can be used to assess the consequence of a given complication. Such knowledge may be used to facilitate effective field-based decisions or programming for intelligent systems to provide a correct response.
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Piccolo, Brian, "The Diagnosis of Well Control Complications during Managed Pressure Drilling" (2013). LSU Master's Theses. 1064.
Smith, John Rogers