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Well Design
Wells are designed by experienced reservoir engineers and are thoroughly reviewed by experts from the Ministère des Ressources naturelles et de la Faune (MRNF) before a well permit is issued.
Shale development requires horizontal wells; the vertical section is typically 2000m deep and the horizontal section can reach 500 m to 1500 m from the drilling rig site.
With horizontal drilling, many wells can be drilled from a single well pad, known as pad drilling. Pad drilling reduces the environmental footprint – or surface area – of well sites.
Prior to setting up equipment, we run through a series of safety checks:
- We rigorously inspect our rigs when we assemble them.
- We confirm that all valves, seals, taps etc are in good working order.
- We pressure test the mud circulating system.
- We place drip trays and mats around potential leak points.
Drilling Mud
The drilling process is still based on the movement of a bit which rotates through rock. We require a fluid called “mud” to lubricate the bit and remove rock cuttings, stabilize the hole, and control the pressure in the wellbore.
Drilling mud is a mixture of fresh water, and different additives that include bentonite clay among others. It is water-based, non-toxic, used routinely every day in North America. The mud forms a protective “cake” around aquifer formations and prevents communication between the new wellbore and the water.
We are committed to full disclosure of mud contents.
At the end of the drilling operation, mud is re-used at the next well. Any mud that cannot be re-used is disposed of at an offsite licensed landfill facility in accordance with provincial standards. Prior to disposal, drilling waste (mud and cuttings) is tested for toxicity and chlorides to ensure that it is disposed of in an appropriate manner.
Groundwater Protection
We understand that the public is concerned about water safety, and we take these concerns very seriously.
Based on years of oil and gas drilling experience, we have developed standard drilling practices specifically designed to protect groundwater. Water aquifers are protected with steel casing that is cemented in place. This is a proven technique approved by the Ministère des Ressources naturelles et de la Faune (MNRF) to protect water aquifers and avoid any groundwater contamination.
Source: Questerre Energy “Hydraulic Fracturing Backgrounder”, September 2010
The casing protects aquifers during production, when gas is flowing up the wellbore, as well as during completion operations, such as hydraulic fracturing. The impermeable nature of the Lorraine shale overlying the Utica shale and significant distance between the Lorraine and aquifers mean that the only pathway between hydraulic fracturing fluids and aquifers is via the wellbore. The cemented casing isolates aquifers from the wellbore.
Step 1: Before beginning drilling operations, we conduct testing on potable water wells located within a 1.0 kilometre radius of our wellsites. These wells are baseline tested against Ministère du Développement durable, de l’Environnement et des Parcs (MDDEP) criteria.
Step 2: The cement we use to cement casing in place is designed according to the exact strength and durability properties which are specific to the oil and gas industry.
We blend cement with additives in precise quantities to ensure it has a “compressive strength” in excess of any pressures it could be exposed to in the well (including fracturing pressures).
Cement properties and testing procedures are regulated by provincial and industry standards.