Well Control: Execution Planning (Part II)
A continuation of the three part series. You can take a look at Part I here: Well Design/Construction.
Inputs Needed: Chosen Service Providers/Contractors, Standard Operating Procedures, Rules and Regulations, Company Safety Policies, Reporting Procedures, Directional Plans, Surveyed Plats, Equipment Specs, etc.
Output: Execution Planning
Taking in all the inputs to create a proper program, which effectively communicates your plan, is of utmost importance in preventing an on-site disaster. Without documentation of how you want your field to operate the design and run the programmed equipment you will have no feet to stand on if an incident was to occur.
An example is as follows, if you know the equivalent mud weight of the productive formation is 12ppg in this township/range and the depth of the formation is 6,000’ TVD, whereas their previous pad the target interval was only 11ppg and its depth was 6,500’ and they don’t weight up to target EMW until 100’ before the target interval, your rig could now be facing a near 4 ppg kick without anyone seeing it coming. The well control situation has now begun and your lack of communication is the key reason the wellsite wasn’t protected and didn’t have the information they needed to weight up in time before cutting the shallower target.
Many would see this as a failure at the wellsite if the influx is not subsequently controlled and a KWM is not circulated without harm or foul to personnel or the environment., but you know and the wellsite knows you are to blame. The next question is whether your well design will stand up to the failure of communication that resulted in a larger than expected kick intensity. An example is as follows:
If your well construction was based on a kick intensity of 2 ppg and due to the improper communication you took a 4 ppg influx, this may result in too large of back pressure held to circulate out the kick while maintaining constant bottom hole pressure resulting in an underground blowout. Communication downhole is a failure of well control and therefore your well design has now failed, due to the absence of communication from engineer to the wellsite during the execution planning phase.
Lets say your pit volume tracker works and the rig catches the volume at a 10 bbl influx but the program never specified to have enough barite for weighting up to 12 ppg? There goes the economic part of delivering the well in a timely and economic matter.
Through improper communication of the execution planning phase these two examples above have A) risked the safety of the well-site team B) created an environmental exposure risk and C) jeopardized the economics of the well.
Personal accountability is something that must be key in our pursuit of well control. Always communicating the minutia of data is not the easiest as the job asks a lot of drilling engineers these days, especially when the drilling engineer becomes part of the geo-steering over night, it truly is a 24-7-365 job. Personally I have found one of the best ways to keep yourself accountable is to setup controls that you must fill out and deliver to the wellsite for every well. You may do it your own way so the details of these documents are preference, but I like to utilize a quick reference sheet for well details, well schematics, a detailed well program that includes safety and shut-in procedures, and all attachments that were provided to you should also be privied to the field. A good way to also start a new project is a well binder that encloses each and every aspect of the program, from driving directions, schematics, design, simulations, vendors documents, contact lists, etc.
We will discuss execution in the next phase of this three part well control series. Thanks for reading!
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