Produced water management has many implications in relation to operation costs, field oil recovery and environment.
Options for Produced Water Management include:
Many operators adopt an integrated approach where all options are considered and evaluated. Production history and profile over the life time of an oil field should also be considered.
Minimisation of water production involves identification of water sources and the use of water shut-off technologies to prevent water getting into the wellbores. Chemical and mechanical water shut-off technologies are available. Downhole separation, subsea separation together with produced water re-injections also play a significant role in minimising water production.
Once water is produced, it must be treated. Treated produced water may be discharged to an environment, re-used or re-injected. For each option, treatment requirements and water quality standards may be different depending on location of the fields and whether produced water re-injection is for disposal or pressure maintenance purposes. Produced water re-injection is on the increase, in the North Sea.
For onshore oil and gas productions, in many places, produced water re-injection is considered to be a more environmentally friendly and economically viable option. Treatment and discharge is still possible, but much tougher regulatory requirements apply. Here in addition to oil in water concentration, other parameters such as pH, total dissolved solids, phenols, heavy metals, H2S, Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) are required to be measured and checked against a set discharge limit.
Further information on Produced Water Management including Produced Water re-injection is contained in the Downloads section.