Oilfield Microbial Reservoir Souring

Today, reservoir souring is a common problem associated with water injection for secondary oil recovery, and souring has been observed in both onshore and offshore systems. Negative consequences of souring are many and include HSE concerns, increased sulfur content in produced oil & gas, and corrosion. Oil companies have been looking for better and more cost effective technology for souring control to achieve best quality of oil.

Uncontrolled microbial activity in oilfields can lead to major asset integrity, safety and environmental problems costing hundreds of millions of dollars. These can be avoided by taking a proactive approach to microbial monitoring and mitigation; saving time, money and improving production.

This course explains the often overlooked aspect of oilfield chemistry and gives hands-on training in how to monitor microorganisms in order to control them. Learning is through an effective blend of classroom theory sessions, hands-on practical and theoretical exercises and group discussions on field case studies.

Upon completion of this course, participants will have a full understanding of the causes of microbial reservoir hydrogen sulphide souring, as well as have an understanding of the actions and processes needed to reliably predict, monitor, control and manage the risks of souring.

• Obtain full understanding of microbiological processes as applied to reservoir and associated topside oilfield systems.
• Develop an understanding of the different microbial souring prediction tools available.
• Be able to assess to data supplied on existing biocide formulations and other microbial control measures appropriate to the system.
• Be able to establish an appropriate souring monitoring programme for the operation.
• Be able to accurately interpret field data on microbiology and souring, assess the effectiveness of any applied souring mitigation strategy and recommend any needed changes to the strategy, including biocide evaluation and optimization.

This course has been specifically targeted to anyone who are assessing, predicting, controlling and managing microbial reservoir souring

Job Titles Include :

• Reservoir Engineers
• Production Engineers
• Operations Personnel
• Technical Personnel
• Management Personnel
• Research & Development Personnel

DAY 1 Oilfield Microbiology

• In depth lectures on oil field and petroleum microbiology
• Classical and new approaches to microbiological monitoring
• Sampling procedures for microbiology covering water, solids and surfaces
• Importance of on-site sampling and representative samples
• Molecular microbiology methods
• Traditional microbial cultivation methods
• Quick kits for microbial assessment
• 40 ways microbes impact the oil industry
• Biofouling and biofilms
• Microbiologically influenced corrosion (MIC)
• Oilfield biotechnology
• Microbiologically enhanced oil recovery (MEOR)
• Microbial control methods – biocides
• Microbial control methods - novel and developing methods

DAY 2 Reservoir Souring - Why is it Important and How Does it Happen?

• Souring of oil and gas fields – why, how and when
• Importance of souring – safety, sour service materials, product quality
• Chemical and physical requirements (nutrients, temperature, pressure)
• Which organisms are responsible?
• Are they indigenous or introduced?
• Bacteria and Archaea – the primary culprits
• Involvement of methanogens and the whole microbial community
• Seawater injection – the usual cause
• Effect of PWRI, mixed water sources and Low Salinity Water Injection
• Sulfate removal for injection water – benefits and drawbacks
• Effect of reservoir structure and geology on souring
• Scavenging of H2S by Iron minerals in reservoirs
• Partitioning of H2S between oil, water and gas
• Effect of GOR & water cut on perceived souring

DAY 3 Reservoir Souring Assessment and Prediction

• Using downhole samples
• Importance of a fixed planned sampling campaign
• Calculating mass balance of H2S – importance and methods
• H2S generation rates estimated from laboratory experiments
• Laboratory experimental souring models – corefloods, sandpacks, flow rigs
• Measurement of H2S in the field, all 3 phases
• Use of 32S/35S isotopes to determine microbiology involvement
• How to predict (estimate) the potential for souring before field development
• How to predict souring from existing field – onset of souring and rate of souring
• The mixing zone souring model
• The biofilm souring model
• Conceptual models and computer models
• Incorporating a souring module into reservoir simulators
• History matching of souring

DAY 4 Control of Souring and Case Histories

• Biocides used in water injection systems
• Biocides designed for downhole use
• Why standard biocide control treatments may not work
• Novel microbial control methods
• Nitrate – sometimes good, sometimes not
• H2S scavengers
• Injection well or production well treatments?
• Industry standards for souring
• Souring risk from MEOR treatments
• Worldwide cases on souring
• Biocide reservoir treatments
• Nitrate reservoir treatments
• Impact of other production chemicals
• Open discussion on cases and strategies