Environmental Disaster, Threat To Life, Kick Circulated Out and Drilling Ahead; what is the differentiator for the final outcome?
As an oil and gas drilling engineer you bear responsibility for the safety of wellsite personnel, responsibility of protecting the environment, protecting fresh water aquifers, and the responsibility to your family to do your best in fulfilling these requirements so you can return to them and see them prosper on the fruits of your labor. I often find myself wondering why is it that a disaster sometimes hit those who may be un-deserving. In a pure oil and gas example one can wonder why someone who has the exact same well construction, drilling program, kick monitoring systems, same experienced consultants, etc. can end up finding themselves at the end of a major blowout/well-control incident and how someone a few miles away in comparable geology only got a phone call that debriefed the engineer on the influx, the shut-in, the new mud weight and how everything was going as planned after a quick but unexciting event that resulted in maybe an hour downtime.
Asking yourself this question may lead to a preparedness level of which your daily grind may have not brought you to otherwise, lets examine three phases of which influence the level of preparedness companies and engineers will be for a well control situation:
Well Design/Construction, Execution Planning, Execution
The following is in no way an all-encompassing debrief on proper well design and execution but rather an overview of how one could approach different facets of their job duties in order to be prepared for the unexpected.
Part I. Well Design/Construction
Inputs Needed: Geology, Reservoir Characteristics, Target Depths, Offset Wells, and Basin History
Tackling an initial well design in any field, whether exploration or development, is as every bit as important as getting the right rig to drill the well, right fleet to frac the well, and right production team to lift the well. Your pressure vessel from the reservoir to the surface is your design. Your ability to be in control of mother earth is your well design. Without a proper well design your ability to have well control, control of the well, goes out the window.
Is there a definition that helps define the duties of what a well design should do? Here is my stab at it,
The well design as constructed by the engineer shall protect all personnel that ever operate the well in any discipline from the production target to their connect point, protect the surface environment and non target reservoirs downhole from all reservoir fluids and pressures of which the production zone bear, and finally allow the well to be drilled, completed, and produced as economically as possible without super-ceding the prior two parts of this said definition.
Feel free to let us know your definition as feedback is greatly appreciated and is part of the evolution of our industry.
The output for any engineer or life decision is usually only as good as the inputs. This is where the engineer cannot rest on his team’s input but should do their best to understand the inputs/variables that were given to them by their team/co-workers. Understanding where to set your surface shoe based on shallow aquifers, competent and impermeable formations, and kick tolerances based on proposed MW needed to control the pore pressure at the next hole section TD is just as important as the pressure rating of your BOP, burst rating of your production string, and pressure rating of your wellhead and choke manifold. As far as the reservoir engineer helping with the frac gradient of shoe setting depths, the influx gradients of all horizons, and the pressure profile or each reservoir, you betcha, just as important.
Once you have defined your well design and feel good about your outputs are you free and clear? A real life scenario without the parties involved is detailed as follows: contractor "X" was drilling ahead in an exploration basin and the geologist wanted to keep drilling vertically and chewing up TVD into a new horizion and the reservoir engineer didn’t know the pore pressure of that horizon, what is your next call? It should be an easy one, your well design is now out the window and you cannot justify the risk of the unknown to every family member on that wellsite or to your own family for jeopardizing their future if the well design was to fail and the surface pressures were to exceed the ratings of your BOPE. Will it be hard to get the buy-in of all parties when they are footing the bill? Yes, will it be even harder if you didn’t get their buy in on the well design before executing the said well? Yes. Having all team members understand each other’s jobs will ultimately allow you to do exactly what you are paid to do.
Understanding that well design/construction is just one part of the large picture should help you tackle the entire project from start to finish. Viewing this form a macro perspective there are two more phases which will help you achieve your goals, execution planning, and execution.
Stay tuned for part II, Execution Planning.
If you would like to be notified when Part II and is published, sign up for blog email updates by hitting the subscribe button on this page.
Petrobids is an Oil & Gas marketplace where operateors and service providers connect.
Read more about us here:
