Maximizing Drilling Efficiency: A Novel Solution to Handle Wellbore Ballooning in High Pressure Formation Through Applying a Fit-For-Purpose Drilling Fluid and Managed Pressure Techniques
Authors: Oqaili A. H. , Alzarea T. N. , Iturrios C. O. 
Published: February 2024

Oil and gas drilling activities are being constantly evolving to master the domain of drilling into abnormally pressurized formations interbedded with depleted zones. Drilling companies venture into more challenging fields in order to satisfy the global demand for hydrocarbons. One of the major focus areas in drilling operations is well control incident as it can be a safety hazard and lead to lost time and cost. The focus area of this paper will be discussing how to tackle wellbore breathing as it can be tricky to manage as a well control situation.

Wellbore breathing (or wellbore Ballooning) phenomenon imposes several well-control challenges with the rig conventional blowout preventers and drilling fluid monitoring equipment. There are many state of the art innovative methodologies in detecting wellbore breathing. The nature of wellbore breathing requires intelligent diagnostic tactics to eliminate the chances of a kick scenario, which could be leading to prolonged flow checks and constant increases of the drilling fluid density to stabilize the well. Once this happens, expectedly the scenario may further lead to a series of loss and kick scenarios that can result in operational challenges such as stuck pipe or wellbore sidetracking. Moreover, leading to series of curing operations under these challenging circumstances. Deploying losses curing techniques has to be tailored since traditional cement curing tactics may remain unsuccessful with ballooning effect resulting in cement contamination jeopardizing the objective. Essentially controlling bottom-hole pressure while attempting to cure losses is detrimental to the success of the process. Wellbore breathing requires intensive care in wells with narrow mud weight profiles. Furthermore, routine operations, such as tripping or cementing the well, requires additional measures to maintain the well integrity and quality at best.

Instead of attempting to control the well by constantly adjusting the mud weight and performing extensive flow checks, this paper will highlight how this situation can be dealt with in a safe and systemic approach. The paper will highlight three different (but combinable) approaches, including the utilization of wellbore strengthen fluid particles to help preventing the wellbore breathing issue from happening in the first place, the utilization of a rotating control device (RCD) to help mitigating wellbore breathing consequences and stabilizing the well, including the technique of placing a cement plug to strengthen the problematic formation utilizing managed pressure cementing (MPC) techniques, and lastly, the paper will show how managed pressure drilling (MPD) equipment can help to detect and resolve the wellbore breathing issue.

The implementation of the mentioned techniques above can result in a safer drilling operation to the rig crew, avoidance of nonproductive time (NPT) and overall, better well integrity.