John Candler, Operation Integrity Development Manager, M-I SWACO, Schlumberger
Eric Lee, Schlumberger
Bremmen Derry, Schlumberger

IPEConnect PRESENTATION DATE: October 24, 2024

Sediment targets for 275 day biodegradation test were researched prior to the completion of the Effluent Limitation Guidelines (ELGs) Feb 5, 2001 and Gulf of Mexico permits Feb 16, 2002 . Method 1647 has basic chemical and physical requirements for the sediment and then also some performance-based requirements. The papers prior to the publication of the ELGs do not fully explain the issues with sediment that has too much organic content, or to too much anerobic bacteria. Practical experience has shown that when sediment contains too much organic content, the background gas production from the organics can blind the test to the gas produced from the base fluids and reduce the discriminatory power of the test. Additionally, too much initial bacteria in a sediment substrate can produce too much gas too quickly or convert too much base fluid to bacteria growth which can produce inconsistent and unexpected results. In a similar manner, not enough bacteria or not enough organic material can greatly add to the lag phase and reduce discriminatory power of the test. The intermediate control will not perform to the required specification if there is not enough initial bacteria or organic matter in the sediment. After the ELGs and GOM permit were issues, the follow up research on Method 1647 and associated sediment continued until the 2006 timeframe when the industry work group the finished the test development and a separate report to the MMS was completed.in 2006.
In order to update and confirm the basic chemical and physical requirements so that new collection sites can be screened, and collection techniques can be refined, over twenty of sediment samples were collected and tested to further identify and define sediment collection characteristics that will work with Method 1647. This presentation will review the findings and discuss development and field application of a new bacteria monitoring technique.