To help assure the successful development and implementation of the mostappropriate waste management strategy, should be thoroughly considered allvariables which may affect the operation. These factors may come from anynumber of areas, including but not limited to operations, logistics, regulatorypolicies, internal company strategy or equipment availability. As the cost forwaste management approaches and surpasses the cost of the actual fluidservices, the importance of the development of the proper response to thechallenge only increases.
An environmental management strategy should address every portion of thefluid systems. Drilling fluid, completion fluid, production fluid, stimulationfluid and cement slurries can all have different residual effects which must beconsidered. Coupled with generated solids such as drilled cuttings and producedsands, the task of deciding on the correct disposal option becomes critical. Byunderstanding the factors that effect each individual operation and area andutilizing correct management practices and procedures, a purpose-designed, compliant option should be identified and implemented. This strategy, backedwith proper monitoring and documentation, can provide the operator with asustainable environmentally responsible and compliant solution.
Environmental legislation varies from country to country, and even specificregion to region within a country, and the legislation may be subject tofrequent changes. Another critical component is the operator's own corporatestandards. These can often be more stringent than regulatory limits, which canhelp prevent future liability for actions taken today. Therefore, propercomprehension of all applicable legislation and the operator's internalstandards is critical. The costs, both direct and in-direct, of non-complianceshould be considered.
The minimization and control of waste which develops from the strategy canalso have the beneficial effect of reducing the number of health-related issuesby minimizing or mitigating effluent discharge through air, water and soilreleases. The benefits realized through proper handling and disposal of wastematerials can have a correlation with reduction of occupational hazards.
With the wide variety of waste and fluid types present in theupstreamoil and gas industry, a detailed plan of disposal should be constructed. Thelogical first step in that plan is the identification of waste streams expectedto be encountered. Once these waste streams have been identified, certain wastetreatment methods will be counter-indicated. Typically the most difficult wastestreams to deal with will be the drilled cuttings and drilling fluid, but allstreams should be considered individually as they may become the determiningfactors in establishing a strategy.
Examples of counter-indicated treatment methods could include:
A salt-saturated drilling fluid would indicate against land farming of thecuttings, as the probable chloride content could be an insurmountableobstacle.
Anticipated drilling of large intervals of oil production sands withincorporation of formation fluids might prevent overboard discharge of anormally compliant water-based cement spacer or slurry.
Drilling a larger diameter interval generates significant more cuttingscompared to smaller hole diameters. Cuttings volume reduction could minimiselandfill space usage.
During well testing, significant amounts of produced sand delivered at highrates can become a factor due to the storage limitations on location versusrealistic injection rates.
Using a rig with insufficient storage capacity to drill a large surfaceinterval in a zero discharge area could prevent disposal by annular cuttingsinjection.