How to Drill an Oil or Gas Well

Drilling an oil and gas well can be a long and complicated process, depending on the location and field you are drilling in. Generally speaking the deeper, higher pressure are the more technically challenging wells to drill.

Once a geological target has been identified a surface location is chosen. This gives you a surface location where the drilling rig will be located and a bottom hole location that will be targeted for oil and gas production.

The drilling engineer will create a stick diagram, drilling program and cost estimate or AFE.

The stick diagram is a single page reference document that includes all relevant well information (licence number, pressures, formation, casing size, cement details, etc.).

The drilling program is a step by step document that details exactly how the well should be drilled. These programs include all of the same data as the stick diagram as well as additional details that may include area specific information, specific safety or operations procedures that should be followed (trip speeds, LOT or FIT’s, etc.).

The Cost Estimate or AFE (Authority for Expenditure) is the authorized or planned cost to drill the well. 

Once a program, stick and AFE are in place services are sourced and procured. This will include all the planned equipment that will be needed during the well including selecting a drilling rig, directional, bits, mud, rentals and much more.

Once all the services are awarded a lease is built at the selected surface location and well center is marked by surveyors.

The drilling rig and ancillary equipment is moved in and the well is spudded.

The surface hole is drilled, cased and cemented to protect any fresh water sources and base of ground water protection (BGWP).

Subsequent hole section are then drilled, cased and cemented which may include intermediate and production casing strings.

Once the well is TD’d (drilled to total depth) it is logged to obtain valuable data about the rock properties and reservoir. After logging is complete it is cased and cemented the drilling rig is moved off of location.

At this point the well is drilled and cased and ready for completions operations to begin. 

What is Drilling Engineering?

Drilling Engineering is the process of planning, designing and costing the drilling operations of an oil and gas well. Drilling engineers will work closely with geologist, reservoir and completions engineers to determine the most effective way to drill a well in order to maximize the potential production of oil and gas reserves. Some key roles a drilling engineer have include casing design, cementing, mud composition and properties, rig specifications and pressure control equipment. In order to drill a well safely and efficiently all of these components must be considered. In addition the drilling engineer must work closely with other departments to ensure the well is suitable for planned completion and production operations. 

What is required to drill an oil or gas well in Western Canada? 

In order to drill a well in western Canada you must be a registered operator with the appropriate provincial regulatory body and obtain a well licence from that regulatory body. 

What is Pad Drilling?

Pad drilling refers to the drilling of multiple oil and gas wells from a single surface location or pad. These wells are often drilled horizontally in opposite directions in order to access a large portion of the downhole reservoir while minimizing the amount of surface impact. 

What is a HPHT Well?

High Pressure High Temperature (HPHT) wells can be some of the most technically challenging wells to drill. This can be due to a number of factors including: mud properties, kick/loss scenarios, wellbore stability issues, etc. 

How do you complete an oil or gas well?

After a well is drilled, it needs to be completed to make it an efficient and safe production well. We wrote an article summarizing the completions process. Read more →

The drilling process is summarized in the following video: