Willard CO2 Separation Plant - Executive Summary |
|
Willard CO2 Separation Plant RMP - Risk Management Plan: Executive Summary Willard RMP Executive Summary 0699 final a.doc - bdj - 06/16/99 Page - 3 ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES The Willard CO2 Separation Plant is committed to worker and public safety. This commitment is demonstrated by the resources invested in accident prevention, such as training personnel and consideration of safety in the design, installation, operation, and maintenance of our processes. This facility, commissioned in August 1988, was designed and constructed utilizing generally accepted industry codes and recommended practices such as ANSI - American National Standard Institute, ASME - American Society of Mechanical Engineers, TEMA - Tubular Exchanger Manufacturers Association, and API - American Petroleum Institute. It is our policy to adhere to all applicable federal, state, and local laws. Our policy is to implement r easonable controls to prevent foreseeable releases of regulated substances. However, if a release does occur, plans have been developed to control and contain such a release. DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES The Willard CO2 Separation Plant is located in a rural area four (4) miles North of Denver City, Texas. Denver City has a 1990 census population of approximately 5,000. Denver City is located in West Texas approximately 90 miles South of Lubbock, Texas and 90 miles North of Midland, Texas. The plant processes a wet (H20) carbon dioxide rich (83% CO2) gas stream to produce a dry CO2 rich (86% CO2) natural gas stream for use in tertiary oil recovery projects in the immediate area. Natural gas liquids (NGLs), sulfur, and hydrocarbon condensate oil are also produced from this process. The plant has several regulated flammables, such as methane, ethane, propane, butanes and pentanes. The Willard CO2 Separation Plant's current capacity is 65 million standard cubic feet per day (MMSCFD). Current plant throughput averages 38 MMSCFD of raw gas from various West Texas tertiary oil recovery projects. The CO2 rich/wet gas stream is compressed, dried, and separated from the NGLs and H2S before returning to tertiary oil recovery projects for re-injection. The compressors and the other rotating equipment are electrically driven except for the emergency electrical generator and firewater pump, which are diesel engine powered. The natural gas fired equipment include: boilers, glycol re-boiler, gas heaters, plant flare and other combustion sources which burn sweet natural gas purchased from outside sources. After the first and second stages of compression, the entire feed gas stream goes through a triethylene glycol (TEG) dehydration system to remove water from the gas stream. Lean TEG absorbs the water and small amounts of hydrocarbon from the gas stream. Th e rich TEG flows to a flash tank, where the hydrocarbon gases are released and returned to the plant inlet for re-processing. From the flash tank, the TEG is regenerated using a direct-fired re- boiler. The water vapor and hydrocarbon separated from the glycol are condensed. The oil and water are subsequently separated from each other. The oil is sold and the water is used for injection in a nearby tertiary oil recovery project. After the gas is dehydrated it enters the Ryan-Holmes process, a patented lean oil absorption gas separation process, that separates the CO2, nitrogen, and methane from the H2S and NGLs. The system includes a closed loop propane refrigeration system for the generation of liquid CO2 used as process reflux. The 86% CO2, rich residue gas leaving the Ryan-Holmes process is compressed to higher pressures. The majority of this gas is mixed approximately 50/50 with third party pipeline CO2 for use in nearby tertiary oil recov ery fields. The remainder, though not mixed, is also used in a nearby tertiary oil recovery field. The CO2/H2S sour NGLs from the Ryan-Holmes process are sweetened with a diethanolamine (DEA) system. Lean DEA removes hydrogen sulfide (H2S) and the remaining CO2 from the NGLs. The now rich DEA is regenerated in the amine re-concentrator by adding heat (via steam) to drive off the CO2 and H2S. The CO2 and H2S from the re- concentrator are routed to the sulfur recovery unit (SRU). The sweetened NGLs extracted from the DEA process are stored in pressurized tanks, then pumped and sold through a third party pipeline. In the SRU, H2S is converted into elemental sulfur. This molten sulfur is stored in a vessel until it is shipped out in insulated trailers and sold. The waste gas from the SRU is then incinerated. Supplemental gas is added to the incinerator to ensure complete combustion of the waste gas stream. Auxiliary equipment includes two (2) steam boilers, three (3) redundant instrument air compressors, one backup electrical generator powered by a diesel engine, electrical and diesel driven fire water pumps, fire monitors throughout the plant and a 30,000 BBL fresh water storage tank for process usage and fire fighting. An open and closed drain system collects miscellaneous plant fluids into API separators. Plant waste oil from rotating equipment and gas liquids from compressor scrubbers are skimmed from the water and pumped into the slop oil tank. The slop oil is pumped offsite for further treating and sold. The wastewater is mixed with boiler and cooling tower blow-down water and pumped to the Willard Unit for use as an injectant in the Willard Unit tertiary oil recovery project. Separate waste disposal wells are available as backup. OFFSITE CONSEQUENCE ANALYSIS RESULTS The worst case scenario (WCS) associated with a release of flammable substances at the plant is a vapor cl oud explosion (VCE) involving the full inventory of the largest pressure vessel containing a flammable mixture of NGLs. The maximum expected liquid inventory of a 37,000 gallon non-refrigerated pressurized storage vessel was assumed to be instantaneously released and ignited, resulting in a VCE. According to EPA's Look-up Tables and Equations the maximum distance to the 1-psi endpoint for this WCS is 0.44 mile. Some industrial sites and residences are within this distance. Although, there are numerous controls to prevent such release and to manage their consequences, no credit for mitigation measures was taken into account in evaluating this WCS. The alternate release scenario (ARS) for a flammable substance at the plant is a VCE resulting from a packing leak on an NGL pump. This release was modeled using Canaryr, a commercial consequence analysis modeling software developed by Quest ConsultantsT. Typical meteorological cond itions for this area are a wind speed of 12 mph, 60% relative humidity, Class D atmospheric stability and an ambient temperature of 70 0F. These conditions were used for modeling this scenario. The maximum release rate was estimated to be 165,000 lbs/hr. The total mass released for this scenario was approximately 13,000 lbs, of which 2,000 lbs was predicted to be within the flammable region. The release is expected to be quickly detected by local combustible gas monitors and isolated by the automatic ESD system (active mitigation) within 5 minutes. The maximum distance to the 1-psi endpoint for this event is 0.10 mile. No public receptors are within this endpoint. This event was selected as being a practical scenario for use in emergency planning and response. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM The following is a summary of the accident prevention program in place at the plant. Processes at the plant that are regulated by the Environmental Protection Agency's (EPA's) risk management program (RMP) regulation are also subject to the Occupational Safety and Health Administration's (OSHA) process safety management (PSM) standard. Therefore, this summary addresses each of the OSHA PSM elements and describes the management system in place to implement the accident prevention program. Employee Participation The Willard CO2 Separation plant complies with the "CO2 Asset Area Safety Management Plan" which encourages employees to participate in all facets of process safety management and accident prevention. Examples of employee participation range from updating and compiling technical documents and chemical information to participating as a member of a process hazard analysis (PHA) team. Employees have access to all information created as part of the plant accident prevention program. Specifically, employees can be involved in the accident prevention program th rough ESOP - "Employee's Safety Observation Process", monthly safety meeting development and presentations, and other documented employee participation plans maintained at the plant. In addition, the plant has a number of initiatives through ARCO Permian "Safety Rules and Standards" underway that address process safety and employee safety issues. These initiatives include formation of safety teams with employee and contractor participation to promote both process and personal safety. Safety teams typically have members from various areas of the plant, including operations, maintenance, engineering, and plant management. Process Safety Information The Willard CO2 Separation Plant has on file a variety of technical documents that are used to help maintain safe operation of the processes. These documents address chemical properties and associated hazards, limits for key process parameters and specific chemical inventories, and equipment design b asis/configuration information. Specific departments within the plant are assigned responsibility for maintaining up-to-date process safety information. Reference documents are available to help employees locate any necessary process safety information. Chemical-specific information, including exposure hazards and emergency response/exposure treatment considerations, is provided in material safety data sheets (MSDSs). For specific process areas, the plant has documented safety-related limits for specific process parameters (e.g., temperature, level, composition) in Plant Data Books, Piping and Instrumentation Diagrams (P&ID), and Startup Manuals. The plant ensures that the process is maintained within these limits using process controls and monitoring instruments, highly trained personnel, and protective instrument systems (e.g., automated shutdown systems). The plant also maintains numerous technical documents that provide information about the design and construction of process equipment. This information includes materials of construction, design pressure and temperature ratings, and electrical rating of equipment. This information, in combination with written procedures and trained personnel, provides a basis for establishing inspection and maintenance activities, as well as for evaluating proposed process and facility changes to ensure that safety features in the process are not compromised. Process Hazard Analysis (PHA) The Willard CO2 Separation Plant has a comprehensive program to help ensure that hazards associated with the various processes are identified and controlled. Within this program, each process is systematically examined to identify hazards and ensure that adequate controls are in place to manage these hazards. The Willard CO2 Separation Plant used the "Multiple Failure Error Analysis" technique to perform the 1994 PHA. The analyses are conducted using a team of people who have operating and maintenance experience as well as engineering expertise. This team identifies and evaluates hazards of the process as well as accident prevention and mitigation measures, and the team makes suggestions for additional prevention and/or mitigation measures when such measures are deemed necessary. The PHA team findings are forwarded to local management for resolution. Implementation of mitigation options in response to PHA findings is based on a relative risk ranking assigned by the PHA team. This ranking helps ensure that potential accident scenarios assigned the highest risk receive immediate attention. All approved mitigation options in response to PHA team findings are tracked until they are completed. The final resolution of each finding is documented and retained. To help ensure that the process controls and/or process hazards do not eventually deviate significantly from the original design safety feature s, the plant periodically updates and revalidates the hazard analysis results. These periodic reviews are conducted at least every 5 years and will continue at this frequency until the process is no longer operating. The results and findings from these updates are documented and retained. Once again, the team findings are forwarded to management for consideration, and the final resolution of the findings is documented and retained. PHA "what-if" and "check list" methods are employed for process changes resulting from a Management of Change (MOC). Operating Procedures The Willard CO2 Separation Plant maintains written process procedures that address various modes of process operations, such as (1) unit startup, (2) normal operations, (3) temporary operations, (4) emergency shutdown, (5) normal shutdown, and (6) initial startup of a new process. These procedures can be used as a reference by experienced operators and provide a basi s for consistent training of new operators. These procedures are periodically reviewed and annually certified as current and accurate. They are revised as necessary to reflect changes made through the management of change process. Training To complement the written procedures for process operations, the Willard CO2 Separation Plant has implemented training programs for all employees involved in operating a process. New operators receive basic training in plant operations if they are not already familiar with such operations. After successfully completing this training, a new operator is paired with a senior operator to learn process-specific duties and tasks. Operators must demonstrate (through tests and skills demonstration) adequate knowledge to perform the duties and tasks in a safe manner on their own before they are allowed to work independently. In addition, all operators periodically receive refresher training on the operatin g procedures to ensure that their skills and knowledge are maintained at an acceptable level. This refresher training is conducted at least every 3 years. All of this training is documented for each operator, including the means used to verify that the operator understood the training. Contractors The Willard CO2 Separation Plant uses contractors to supplement its work force, especially during periods of increased maintenance or construction activities. Because some contractors work on or near process equipment, the plant has procedures in place to ensure that contractors (1) perform their work in a safe manner, (2) have the appropriate knowledge and skills, (3) are aware of the hazards in their workplace, (4) understand what they should do in the event of an emergency, (5) understand and follow site safety rules, and (6) inform plant personnel of any hazards that they find during their work. This is accomplished by providing contractors with (1) a process overview, (2) information about safety and health hazards, (3) emergency response plan requirements, and (4) safe work practices prior to their beginning work. In addition, the Willard CO2 Separation Plant evaluates contractor safety programs and performance during the selection of a contractor. Gas Plant personnel periodically monitor contractor performance to ensure that contractors are fulfilling their safety obligations. Pre-startup Safety Reviews (PSSRs) The Willard CO2 Separation Plant conducts a PSSR for any new facility or facility modification that requires a change in the process safety information. The purpose of the PSSR is to ensure that safety features, procedures, personnel, and equipment are appropriately prepared for startup prior to placing the equipment into service. This review provides one additional check to make sure construction is in accordance with the design specifications and that all sup porting systems are operationally ready. The PSSR review team uses checklists to verify all aspects of readiness. A PSSR involves field verification of the construction and serves a quality assurance function by requiring verification that accident prevention program requirements are properly implemented. Mechanical Integrity The Willard CO2 Separation Plant uses generally accepted industry recommended practices and procedures to maintain pressure vessels, piping systems, relief and vent systems, controls, pumps and compressors, and emergency shutdown (ESD) systems in a safe operating condition. The basic aspects of this program include: (1) conducting on-site and off-site training (both company and vendor based) (2) contracting of third party companies for specific tasks, e.g. ultrasonic thickness (UT) testing, pressure safety vessel (PSV) testing, and API 510 vessel inspection, (3) performing inspections and tests, (4) correcting identified def iciencies, and (5) applying quality assurance measures. In combination, these activities form a system that maintains the mechanical integrity of the process. Maintenance and operating personnel receive training on (1) an overview of the process, (2) safety and health hazards, (3) emergency response plans, and (4) applicable safe work practices to ensure that they can perform their jobs in a safe manner. Inspections and tests are performed to ensure that equipment functions as intended and to verify that equipment is within acceptable limits (e.g., adequate wall thickness for pressure vessels). If a deficiency is identified, employees will correct the deficiency before placing the equipment back into service (if possible), or a management of change team will review the use of the equipment and determine what actions are necessary to ensure the safe operation of the equipment. Another integral part of the mechanical int egrity program is quality assurance. The Willard CO2 Separation Plant incorporates quality assurance measures provided by plant engineering and the maintenance department, in the purchase and repair of equipment. This helps ensure that new equipment is suitable for its intended use and that proper materials and spare parts are used when repairs are made. Safe Work Practices The Willard CO2 Separation Plant has long-standing safe work practices in place to help ensure worker and process safety. Examples of these include: (1) control of the entry/presence/exit of support personnel, (2) visitors are given the plant safety orientation presentation and written exam annually, (3) a lockout/tagout procedure to ensure isolation of energy sources for equipment undergoing maintenance, (4) a procedure for safe excavation and trenching, (5) a permit and procedure to control spark-producing activities (i.e., hot work permit), (6) a per mit and procedure to ensure that adequate precautions are in place before entry into a confined space and (7) MOC - management of change procedures. The plant is also covered by the ARCO Permian Safety Manual, ARCO Permian CO2 Asset Area Safety Management Plans, Willard CO2 Plant Electrical Safety Plans, the Willard CO2 Plant Emergency Contingency Plan, and the ARCO Permian Drug and Alcohol Plan. These procedures (and others), along with training of personnel, form a system to help ensure that operations and maintenance activities are performed safely. Management of Change The Willard CO2 Separation Plant has a comprehensive system to manage changes to all covered processes. This FCR - Facility Change Request system requires that changes to items such as process equipment, chemicals, technology (including process operating conditions), procedures, and other facility changes be properly reviewed and authorized before implementatio n. Changes are reviewed to (1) ensure that adequate controls are in place to manage any new hazards and (2) verify that existing controls have not been compromised by the change. All pertinent chemical hazard information, process operating limits, and equipment information, as well as procedures, are updated to incorporate these changes. In addition, operating and maintenance personnel are provided any necessary training on the change. Incident Investigation The Willard CO2 Separation Plant promptly investigates all incidents that result in, or reasonably could have resulted in, a fire/explosion, toxic gas release, major property damage, environmental loss, or personal injury. The goal of each SPI - Serious Potential Incident investigation is to determine the facts and develop corrective actions to prevent a recurrence of the incident or a similar incident. The investigation team documents its findings, develops recommenda tions to prevent a recurrence, and forwards these results to the Asset Area Manager for approval. The Willard CO2 Separation Plant management is then responsible for resolution. Corrective actions taken in response to the investigation team's findings and recommendations are tracked until they are complete. The final resolution of each finding or recommendation is documented, and the investigation results are reviewed with all employees (including contractors) who could be affected by the findings. Incident investigation reports are retained for at least 5 years so that the reports can be reviewed during future PHAs and PHA revalidation. Compliance Audits To ensure that the incident prevention program is functioning properly, the Willard CO2 Separation Plant periodically conducts an audit to determine whether the procedures and practices required by the accident prevention program are being implemented. Compliance audits are conducted at least every 3 years. Both hourly and staff personnel participate with the audit team members. The audit team develops findings that are forwarded to plant management for resolution. Corrective actions taken in response to the audit team's findings are tracked until they are complete. The final resolution of each finding is documented, and the two most recent audit reports are retained. CHEMICAL-SPECIFIC PREVENTION STEPS The processes at the Willard CO2 Separation Plant have potential hazards that must be managed to ensure continued safe operation. The following is a description of existing safety features applicable to prevention of accidental releases of regulated substances in the facility. Universal Prevention Activities The accident prevention program summarized previously is applied to all RMP-covered processes at the Willard CO2 Separation Plant. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors. Specialized Safety Features The Willard CO2 Separation Plant has safety features on many units to (1) contain/control a release, (2) quickly detect a release, and (3) reduce the consequences of (mitigate) a release. The following types of safety features are used in the covered processes: Release Detection z Hydrocarbon, H2S, and O2 detectors with alarms Release Containment/Control z Process relief valves that discharge to a flare header to capture and incinerate releases z Valves to permit isolation of the process (manual or automated) z Automated shutdown systems for specific process parameters (e.g., high temperature) z Redundant equipment and instrumentation (e.g., un- interruptible power supply (UPS) for process control system, redundant instrument air compressors, backup firewater pump) z Vapor recovery units (VRU) and atmospheric p ressure and vacuum relief devices on tanks. Release Mitigation z Fire suppression and extinguishing systems z Trained emergency response personnel z Personal protective equipment (e.g., chemical protective clothing, self-contained breathing apparatus) z Fire monitors for fire fighting FIVE-YEAR ACCIDENT HISTORY The Willard CO2 Separation Plant has an excellent record of accident prevention. The plant has not had any RMP recordable incidents over the past five years. Nor have there been any incidents with offsite consequences. EMERGENCY RESPONSE PROGRAM INFORMATION The Willard CO2 Separation Plant maintains a written emergency contingency plan, which is in place to protect worker and public safety as well as the environment. This program incorporates elements of the nationally accepted Incident Command (IC) System. The program consists of procedures for responding to a release of a regulated substance, including the poss ibility of a fire or explosion if a flammable substance is accidentally released. The procedures address all aspects of emergency response, including proper first aid and medical treatment for exposures, evacuation plans and accounting for personnel after an evacuation, notification of local emergency response agencies and the public if a release occurs, and post incident cleanup and decontamination requirements. In addition, the plant has procedures that address maintenance, inspection, and testing of emergency response equipment, as well as instructions that address the use of emergency response equipment. Employees receive training in these procedures as necessary to perform their specific emergency response duties. The emergency response program is reviewed annually and updated when necessary based on modifications made to plant processes or other plant facilities. The emergency response program changes are im plemented by informing and/or training all personnel involved in the changes. The overall emergency response program for the Willard CO2 Separation Plant has been reviewed by local area emergency organizations: the Fire Department, the Sheriff Department, and medical facilities. This coordination shall include periodic meetings of these organizations. The Willard CO2 Separation Plant has around-the-clock communications capability with appropriate emergency response organizations (e.g., fire and sheriff departments). This provides a means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident. In addition to periodic meetings with the above organizations, the Willard CO2 Separation Plant will conduct emergency drills that involve the emergency response organizations. The plant will also provide periodic refresher training for local emergency personnel regarding the hazards of regulated substances in the plant. PLANNED CHANGES TO IMPROVE SAFETY The Willard CO2 Separation Plant resolves all findings from PHAs, some of which result in modifications to the process. The following types of changes are planned over the next few years in response to PHA, safety audit, and incident investigation findings: z Revise written personnel training programs z Revise written plant wide process operating procedures z Install additional ESD valves in the process area z Establish periodic process reviews and emergency response training with local emergency responders |