HYDROGEN SULFIDE In the Oilfield
OVERVIEW General H 2 S Information API Guidance External Reguations
WHAT IS H 2 S Colorless gas/invisible Flammable/Explosive Heavier than air Extremely toxic Corrosive Rotten egg smell Deadens sense of smell
WHY DOES H 2 S OCCUR Biological breakdown of organic matter in an anaerobic environment
HEALTH EFFECTS Low concentrations (<10ppm) irritation of eyes, nose, throat and respiratory system Moderate concentrations (10<x>30ppm) headache, dizziness, nausea, coughing, vomiting and difficulty breathing High concentrations (>30ppm) shock, convulsions, coma, death
H2S Kills in 3 ways H2S blocks Oxygen from bonding to your red blood cells Red blood cells carry H2S to your brain causing your respiratory system to shut down H2S mixes with water in our lungs to form acid which can cause Pulmonary Edema (aspirates on own blood)
EXPOSURE LIMITS ACGIH TLV (8hr)= 10 ppm API Recommendation = 10 ppm OSHA ceiling (15 min)= 20 ppm OSHA peak (instantaneous) = 50 ppm IDLH = 100 ppm Immediate death level 1000 PPM knocked out immediately Death in 3 to 5 minutes
Symptoms of Exposure Burning eyes Sore throat Respiratory Irritation Coughing Headache Dizziness Nausea Fatigue Confusion Loss of sense of smell
OTHER PHYSICAL PROPERTIES Explosive (flammable range is 4.3 to 46%) Reacts with water to form Sulfuric Acid Tears Lungs Reacts with iron/steel to form Iron Sulfide (extremely flammable) Iron sponge Burns to form Sulfur Dioxide (toxic gas) May lead to metal fatigue
H2S PRODUCTION
H2S PRODUCTION at Vent wells Red Willow PPM can change need to pay attention to your monitor Produced water and production tanks East Texas wells 9,500 ppm West Texas wells Trace
AMERICAN PETROLEUM INSTITUTE Recommended Practice 49 -Recommended Practice for Drilling and Well Servicing operations Involving Hydrogen Sulfide Applies to well drilling, completion, servicing, workover, downhole maintenance and plug & abandonment procedures. API 54 defaults to RP 49 for H2 Establishes location classifications Addresses personnel training, monitoring equipment, personal protective equipment, contingency planning and emergency procedures. Also establishes Sulfur Dioxide requirements
LOCATION CLASSIFICATIONS No Hazard Area Condition 1 Area low hazard <10 ppm Condition 2 Area medium hazard >10ppm, <30 ppm Condition 3 Area high hazard >30 ppm
WARNING SYSTEMS Condition 1 Area warning sign with green flag or light Condition 2 Area - warning sign with yellow flag or light; visual and audio alarms Condition 3 Area warning sign with red flag or light; visual and audio alarms
MONITORING Equipment Mixture of fixed and portable monitors as needed to protect workers Red Willow uses Gas Alert Microclip portable monitors Alarms at 10 PPM Fixed monitors are utilized in East Texas Required by Texas Railroad Commission due to Radius of Exposure
MONITORING EQUIPMENT Used during drilling activities where a potential of H 2 S exceed action levels exists. Located in the following areas: Bell nipple Mud return line or shale shaker Pipe-trip tank Driller s station Living quarters Other areas of potential accumulation Calibrated and functionally tested per manufacturer Bump test every 4 days Calibrate monthly (30 Days)
Other Federal and State Requirements BLM -Onshore Oil and Gas Order No. 6, Hydrogen Sulfide Operations Texas Railroad Commission Rule 36
CONTINGENCY PLAN May be required by certain federal, state or local agencies. Must contain: Facility specific description and maps Monitoring equipment locations Safety equipment locations Safe breathing area locations Evacuation routes Training and drill requirements Emergency response procedures
Keys you need to remember Where you may find H2S Vent wells Produced water tanks East Texas wells West Texas wells When to be on alert for H2S When at above locations When gauging tanks
Keys you need to remember What to do if your monitor alarms Assume it is for real Leave the location upwind and uphill Report hit to EHS and supervisor Know symptoms of H2S Learn local rules if you are traveling to off reservation locations BLM Texas Railroad Commission
Conclusion Take it serious!!!! Questions?
Scenario # 1 You are out at one of the vent wells and have a member of the Energy Department with you. While you are there, your gas monitor alarms. You look at it and see that the alarm that is going off is the H2S alarm. The individual with you is not sure what to do. Discuss the action you will take. What you should say: Immediately exit the location by going up wind and uphill if possible. Scenario #2 You have been asked to provide the specifications for H2S monitoring equipment, etc. for a vent well. List and discuss what specific equipment you would need to meet our standards? What you should say: All vent wells should have a sign posted stating H2S Poison Gas and there should be a wind sock on location to monitor wind direction. Scenario # 3 You have been asked to discuss the dangers of H2S to a group of individuals who have limited or no knowledge of the gas look at the list below and discuss the issues involved with each item and the significance of each issue (example colorless the fact that it is a colorless gas means that it may be in the atmosphere and you don t and won t know it thus the need to always have your monitor on). Colorless Flammable Heavier than air Extremely toxic Rotten egg smell Deadens sense of smell What you should say: Colorless you can t see H2S so you need another method of detecting it Flammable- H2s is flammable but when it becomes flammable it will be in a concentration of 40,000 PPM so if you exit the site when your gas monitor alarms, you will not need to worry about the flammable range Heavier than air-h2s is heavier than air so be aware that in might be found in low spots Extremely toxic H2S can kill you at concentrations of 1000 PPM in a matter of minutes Rotten Egg Smell H2S can be smelled in low concentrations Deadens sense of smell H2S can deaden your olfactory nerves so you can t smell anymore thus the need for a gas monitor Scenario # 4 You need to manually gauge a tank that has been known to occasionally to have H2S in the produced water. Describe the proper precautions you would take to safely gauge the tank. What you should say: ensure you have a monitor, check wind position, stand upwind from thief hatch, open at arm s length, check atmosphere above hatch with monitor. Don t stick you face into hatch. Do not gauge if you get an H2S hit.