Oil and Gas are formed from organic material buried deep inside the earth's surface at a specific
pressure and temperature conditions. These natural resources are trapped beneath the
impermeable layers in porous and permeable rocks known as a reservoir. These Oil and Gas bearing
reservoirs can be found onshore or offshore and requires a great marvel of engineering and
expertise to explore, reach and produce Oil and Gas from these reservoirs. Initial wells
drilled to produce these resources were shallow, simple, and located onshore, however with the
increase in their demand drilling engineers reached challenging locations, drilling depths, and
followed complex trajectory wells, which has resulted in an increased budget of the project
exponentially.
Drilling operation planning involves a lot of domain-specific expertise in well
trajectory designing, Bottom Hole Assembly (BHA) designing, Drill Bit selection w.r.t
formation compressive strength, mud type, and mud weight selection based on pore
pressure/fracture pressure/differential sticking limit/wellbore stability limit, drilling string
rotational speed and WOB determination based on BHA dynamics.
The drilling operational efficiency enhancement is broadly evaluated on:
Execution of well without any downhole complications and Increased ROP or drilling rate.
Commonly encountered Down hole complications while drilling operations are circulation
loss, well influx, and stuck pipe, among these problems, circulation loss is dependent upon
formation characteristics and cured by using suitable Lost Circulation Material (LCM) like calcium
carbonate (CaCO3), wood fibers, polymers, etc. Well control issue can be resolved by proper
selection of mud weight and drilling practices, whereas stuck pipe issue requires a
detailed analysis of multiple drilling parameters.
Stuck pipe is a situation when the BHA is become immovable inside the wellbore at a particular
depth either due to string pack-off, drill string sticking, stuck in ledges,
