My Career in Sour Gas

After graduating in Petroleum Engineering from the University of Alberta in the spring of 1958, my first job in the oil patch was as a roughneck on a drilling rig which drilled an oil well in central Alberta. I had worked for an oil and gas company the previous year as a summer student, and obtained regular employment upon graduation. The company’s general policy for training engineers was that they had to work on a drilling rig for one well, and then work in various field locations for about ten years with increasing responsibilities before moving to the head office. That was more or less my experience. Some attractive features of this policy were that the company provided houses at each of the field district locations for the District Superintendent and the engineer, a company car, plus two additional weeks of vacation. Another excellent feature was that the engineers were transferred to a different district every year to eighteen months, which provided hands-on field experience in a great variety of oil and gas operations. This experience was very helpful in later years in positions with management responsibilities.

After my drilling experience I worked for a short stint in the head office in Calgary. I was then transferred to a field office in a sour oil field as Junior Engineer and worked there for about two years. My next assignment was to a high-pressure sour gas condensate field in 1961, the Windfall field west of Whitecourt, Alberta. The reservoir fluid contained about 15% H₂S and about 6% CO₂, and was very rich in heavier hydrocarbons. The exploitation of the retrograde condensate pool included cycling gas for pressure maintenance to achieve maximum liquids recovery. The gas for injection and pressure maintenance was brought from a very sour gas pool about 28 miles away, and contained about 26% H₂S and about 6% CO₂. The pool to be cycled had been discovered about eight years earlier, but the development had to wait several years until gas sales contracts for export to California were approved by the Canadian government. The owners of the pool then contracted the gas sales to begin on April 1, 1962. Development wells had been drilled in prior years, but had not been completed, beyond the installation of the production casing strings. A major sour gas treating plant and sulfur recovery facility were constructed during 1961, as well as high-pressure sour gas gathering and gas injection pipeline facilities.

My main responsibility during the summer of 1961 and the following winter was to complete about a dozen high-pressure sour gas wells. The responsibilities included generating the completion program and cost estimate, and upon approval of the program and cost estimate, I had to order the completion equipment, hire a service rig, and then supervise the service rig activities during the well completion work. Since time was of the essence to get all of the wells completed and tested prior to the start of gas sales on April 1, 1962, the service rig work continued 24 hours per day. The work in the summer and fall of 1961 was relatively routine, but during the following winter the weather was very cold with a lot of snow. It was a relief by March of 1962 to see more daylight for the service rig work. However, the first week in March is unforgettable, as the temperature was minus 40°F during the day and about minus 45°F during the night west of Whitecourt in Alberta. It took one whole week to trip the tubing for an 8,000-ft well to repair a tubing leak. A lot of time was taken up by steaming virtually everything.

I continued working in the Windfall field until the summer of 1964. My responsibilities in 1962 changed to field engineering, flow measurement and flow assurance. This was my first experience with the problem of hydrates in meter taps and flowlines. Initially I could not understand how hydrates could form in the dehydrated sour injection gas. I then learned that “dehydrated gas” did not have all of the water vapour removed. Once the ambient temperature dropped below the water dewpoint temperature of the “dehydrated gas,” water became available for the formation of hydrates. Compressibility factors for any gas calculations were based on experimental data.

Since the produced and injected fluids were very sour, great care was taken to ensure that all operations were conducted with the utmost of care and safety. Nevertheless, there were two incidents where I was knocked out by H₂S. The first occurred at a wellsite where a well test was in progress, which I was supervising. A well testing company supplied all of the test facilities as well as the operators who conducted the test. The particular sour well also produced a lot of condensate. The well location was remote from the gathering system, so all of the gas was flared during the test and the raw, volatile condensate was temporarily stored in a couple of tanks at the test wellsite. The responsibility of the test operators was to record various test parameters on a regular basis, and switch tanks when a tank was nearly full. The raw condensate from the full tank would then be hauled to a pipeline terminal via a tank truck. When I arrived at the well location on one occasion, I was horrified to see that one tank was overflowing, and the condensate was flowing down the slope towards the flare equipped with a relatively short flare stack. Upon checking the operators, I found that they were playing cards in their trailer. They quickly realized the gravity of the situation, and one operator rushed in to switch tanks by opening and closing certain valves. Due to not masking up and the H₂S atmosphere in the vicinity of the tanks, he was overcome by H₂S. The other operator then rushed in and pulled the first operator away from the tanks in an upwind direction. Since the tanks had not been fully switched, and condensate was still running from the top of the full tank, I rushed in and completed the switching of the tanks. I felt the onset of the effect of the H₂S gas, but managed to run away about 20 feet in an upwind direction before I lost consciousness. I don’t know for how long I was unconscious, but it probably was not more than a few seconds. Both the operator and I recovered without any ill effects.

My second episode occurred in the middle of the night in the winter of 1963/1964. The high-pressure very sour gas injection facilities included four injection wells, spaced at different locations in the pool being cycled. Since not all injection wells would need to be on line all of the time, one or two wells could be shut in for part of the time. Part of my responsibility was to ensure that the injection wells would be available for service as needed. On this particular occasion, I received a request from the plant to open up a well that had been shut in for a while. Since the operation in the field always required a “buddy system,” rather than call out two operators, I decided that I would go along with the operator who was on shift in the field office, and help him open the master valve of the injection well. The wellheads of these high-pressure injection wells were very tall, and a platform with steps from two sides was erected at each well so that the manual operation of the wellhead valves could be easily performed. It was the middle of a very cold night when the two of us climbed up on the platform to manually open the four-inch master gate valve. Since it was very hard to open the valve, both of us stood close to the valve and tried to slowly open it by pulling on the circular handle. Once we had it moving slowly, a small squirt of very sour gas came out of the grease nipple on the valve bonnet. This shot of sour gas hit me in the face. Both of us hurried down the separate steps to the ground. I happened to be holding the flashlight, and as I fell down from the steps of the platform, I became unconscious and fell face down into the snow on the ground, which was about 2 feet deep. The operator was not affected by the sour gas, but when he got down his side of the platform and turned around he could not see anything in the darkness. I was lying in the snow, and the flashlight was buried under me. When he realized what had happened, he came around to where I was down, and turned me over. At about that time I was regaining consciousness, and we proceeded with opening the well for injection, but with great care.

In mid-1964 I worked in the Calgary head office for a few months in reservoir engineering. Thereafter, I was transferred to a location in northern Alberta, to look after the development of a sweet oil pool for about one year. In 1965 I became the manager of a district operation that included a variety of oil and gas operations. The district office was in a small town in northern Alberta. I became interested in computers, and enrolled in a correspondence course in Fortran programming.

In the summer of 1966, I was offered a position in a sour gas project as plant and field engineer, which I accepted due to my desire to gain experience in sour gas processing. This was a relatively new sour gas development located a short distance west of Calgary, Alberta, called the Wildcat Hills Unit. The gas treating and sulfur recovery facilities were designed in a two-train mode, with each train capable of carrying 50% of the maximum inlet rate. Monoethanol amine was the treating solvent. The sour fluids consisted of gas containing 4% H₂S, 6.5% CO₂, about 5 Bbls/MMscf of raw condensate and 0.75 Bbl/MMscf of condensed water. The design raw gas inlet rate to the plant was in the order of 100 MMscf/d at about 1000 psig. The project superintendent at that time, Dr. Alexander Petrunic, was a very capable and technically innovative person. My responsibilities included well completion work for the high-pressure sour gas wells that were drilled to maintain or to increase the gas production capacity, as well as plant and field engineering work. Since this project entailed a lot of sour gas challenges which were new to the company, Dr. Petrunic virtually used the sour gas treating and sulfur recovery plant as a large laboratory, to increase sour gas technology and plant efficiencies. This was an excellent opportunity for me to be involved in problem identification and development of solutions. In 1968 Dr. Petrunic published a paper which highlighted problem areas and described the innovative changes that were made in the plant under his direction. Some of these problems and solutions were:

1. Identification of causes of emulsions in the three-phase sour gas plant inlet separators;
   • Causes: inhibitor in gathering system; reaction products in gas from well stimulation.
   • Solution: test and select different inhibitor; longer well flaring for clean-up.
2. Corrosion of carbon steel trays in regenerators;
   • Solution: replace with stainless steel trays
3. Corrosion of carbon steel wall of regenerator;
   • Solution: identify coating that can withstand high temperature and type of fluids in the regeneration vessel through experimentation in an autoclave; a coating with gunite was found to be best.
4. Corrosion/erosion in vapour lines from reboiler to still;
   • Solution: replace lines with larger diameter lines
5. Small contactor on rich solution flash tank to recapture acid gas flashed from treating solution;
   • Solution: install larger diameter and taller tower;
6. Foaming problems in reclaimer;
   • Causes: too much anti-foam agent in amine solution;
   • Solution: filter the solution going to the reclaimer through a small charcoal filter;
7. Difficulty in meeting sulfur recovery requirement;
   • Solutions:
     1. improve front end burner configuration;
     2. extend length of reaction furnace to increase retention time of combustion products at high temperature, from 0.7 seconds to 1.5 seconds;
     3. install checker walls in reaction furnace to increase mixing of combustion gases;
     4. replace crushed bauxite and pelletized bauxite with activated alumina catalyst;
     5. install centrifugal separators upstream of each reheater ahead of each catalytic converter to remove sulfur mist from process gas;
     6. install coalescing separator to remove sulfur mist from tail gas ahead of sulfur plant incinerator;
     7. perform periodic in-place regeneration of faltering catalyst to restore catalytic activity.

These and other innovations throughout the plant provided a great experience for me as a new engineer in sour gas processing. Sadly, Dr. Petrunic and his wife Draga were killed in a tragic airplane accident in December, 1969. They had visited friends in Caracas, Venezuela, and upon their return trip the plane crashed shortly after takeoff from Caracas airport.

In 1967, the Engineering Department at the University of Calgary instituted a policy whereby engineers working full-time in industry could register for a Master of Engineering degree, without the requirement of full-time registration in the department. The requirement was that the qualifying participants in the program had to successfully complete six to eight post-graduate courses over a flexible time period, as well as complete a research project. The courses were available in the evenings at the university. The program was attractive to me to gain theoretical knowledge about gas processing, mass transfer and hydrocarbon thermodynamics in general. It also made it possible for me to gain familiarity with computers, as I had a basic knowledge of Fortran at this time.

I registered in the program in the fall of 1968, with the encouragement of Dr. Petrunic. At this time I had been married for eleven years and my wife and I had three young boys. As was company policy, we lived in a company house outside of Calgary to be near the work location, and so I commuted to the university after work. I completed eight courses, two courses per semester, by the spring of 1970. To perform the research project, Dr. Khalid Aziz was appointed my research supervisor in 1969. Dr. Aziz and I had graduated in Petroleum Engineering at the University of Alberta in 1958. Dr. Aziz subsequently obtained a Master’s degree from the university, and then a Ph.D. degree from Rice University before becoming a professor at the University of Calgary. A few years later, he became a professor at Stanford, and throughout his career received many awards from the Society of Petroleum Engineers of AIME for his work in fluid flow and reservoir modelling.

When I asked Dr. Aziz about what research projects were available, he handed me a list of about 60 projects. Many of them were highly theoretical, which I felt I was not qualified for. However, one project interested me very much, namely the development of a computer method for estimating the compressibility factor (Z factor) for sour natural gas. The reason this interested me was that it had direct application to the work I was doing in the plant and field in calculations of metering, volumes in reservoirs, vessels and pipelines and gas flow in piping. Up to this time, compressibility factors for sour gas were developed experimentally on sour gas samples in commercial labs. I completed the project, together with my course requirements, by the spring of 1970. I expanded the project to also develop a chart method for estimating the compressibility of sour natural gas. In the meantime, I had become the Wildcat Hills Unit Superintendent, with responsibility for the plant and field operations, at the end of 1969.

A couple of other topics dealing with sour gas interested me because I had to make estimations in such topics in my general engineering work, namely water content at saturation and hydrate formation temperature at elevated pressures. While chart correlations for estimating these properties had been available for sweet gas and to some extent for hydrates for sour gas, I felt that there was a need for better chart estimating methods. At this time computer methods were not as yet readily available for such estimates. With the help of a dedicated engineer, Chris Baillie, we developed a chart method for estimating the hydrate temperature of sour gas at elevated pressures and a broad range of sour gas compositions. Several years later, with the help of my son Gordon, who had graduated in engineering at the University of Calgary, we developed a chart method for estimating the water content of sour gas over a wide range of pressures, temperature and acid gas contents. These three chart methods are included in Section 20 of the GPSA Engineering Data Book (estimation of hydrates and water content) and in Section 23 (Z Factor). The chart methods developed during the 1970’s and 1980’s were subsequently replaced by computer methods, but they are still useful for quick estimation of the properties when a computer is not at hand.

In the early 1970’s, while being responsible for the Wildcat Hills plant and field operations, I was also serving on some committees as company representative. One such committee was to supervise a research effort in multi-phase metering of high-pressure sour gas that contained about 70 Bbls/MMscf of condensate with some water. My employer had a substantial interest in a high-pressure sour gas project in northern Alberta that had a similar composition to the Windfall field in which I had worked during the early 1960’s. The field to be developed in the 1970’s was owned by 4 companies, including my employer, Canadian Fina Oil and Gas Ltd. (Fina). The owners were reluctant to invest in high-pressure sour gas separators at every wellsite. They felt that major capital and operating savings could be achieved if a method could be identified for metering the raw fluids at each wellsite, as was the regulatory requirement, without the installation of a separator. Such a vessel in high-pressure sour gas service, with level controls, metering of three streams, pressure relief stack with flaring assurance, is very expensive and maintenance intensive. The objective of the owners was to perform research under controlled conditions to identify a metering method that would avoid the need for the installation of a high-pressure separator and fluid meters on the three phases at each wellsite. One of the owners in this project was Hudson’s Bay Oil and Gas, which was owned by Conoco. Since Conoco had research facilities in Ponca City, Oklahoma, it was awarded the contract to perform the research. The regulator had agreed that the regulation requiring wellsite separation and metering would be relaxed if an acceptable method of metering the multiphase stream to the regulator’s satisfaction could be identified. Progress reports were to be submitted periodically to the regulator.

After extensive experiments with every type of meter available at the time, including the orifice meter, there was no one meter that was found to be acceptable in meeting the regulatory requirements. A final, comprehensive report to this effect was submitted to the regulator. (A copy must be hidden somewhere in Conoco’s offices in Ponca City.) Upon reviewing the literature, I came across an article in World Oil by Professor Schuster whose experiments had shown that wet gas can be metered satisfactorily if the gas/liquid ratio at meter run conditions were known. I then developed a mathematical method that was similar to Professor Schuster’s method for the specific project under research. This was then submitted to the regulator, who agreed that the method had merit. Approval was given for multi-phase metering for the development, subject to periodic verification with a mobile separator and testing. I did further research in this area, mainly through further literature searches, and felt that a general adjustment factor could be developed that would give accurate results with multi-phase metering with an orifice meter if the liquid/gas properties could be estimated, and the ratios at meter conditions were known.

After moving to the Calgary office into operations management in 1974, I served as company representative in various industry organizations. This included being company representative, and later as Director, at Alberta Sulphur Research Ltd. (ASRL). This research organization was set up in 1963 by about a dozen companies, including my employer, at the University of Calgary to perform basic research in sour gas and sulfur. ASRL has performed research since start-up in virtually every aspect of sour gas production through the entire processing spectrum of sour gas production, treating, sulfur recovery to acid gas compression and injection. The current membership of this organization includes companies from all over the world where there is sour gas. My term as company representative ended when my employer, Petrofina Canada, was bought by PetroCanada in January, 1981. I still maintain contact with ASRL by being invited to their semi-annual presentations on their current research activities.

My first position with PetroCanada was as manager of all gas plants operated by the company. This included several high throughput sour gas plants with sulfur recovery. A short time later I became manager of all field and plant operations. I was still convinced that a suitable multi-phase metering correlation should be developed. An engineer in my department, Mr. David Richardson, was looking for a research project in his Master of Engineering program at the University of Calgary. I suggested to him to look at research in multi-phase metering on a field scale. He was interested in such a project, and received approval from his research supervisor at the university. Upon obtaining company approval and funds, Mr. Richardson designed a facility with six orifice meters in various orientations, different meter tube diameters and the flexibility of testing with different beta ratios. A well was selected in the company’s operation where the metering test equipment could be hooked up. One feature was that different liquid/gas ratios could be tested by pumping either water or condensate into the gas flow stream upstream of the meters. Mr. Davidson supervised the tests personally, and recorded all data with chart recorders and by computer. He subsequently analyzed the results and wrote his thesis. He also developed a correlation for interpreting the multi-phase meter readings into gas volumes, knowing the properties of the liquid and the in situ liquid/gas ratios. I subsequently modified his factor into more common gas field terms. I still feel that multi-phase metering can be used for reasonably accurate metering with an orifice meter if the in situ liquid and gas properties are known, and there is steady flow without slugging. In high-pressure sour fluid applications this approach can save a lot of capital and operating expense.

In 1985 I prepared the report on “Control of Sulphur Products Emission from Sour Gas Plants” for the meeting of the International Gas Union in Munich, Germany. Persons from several companies contributed to this report.

In January 1987 I retired from PetroCanada, and became a consultant. My first job was with PetroCanada International Assistance Corporation (PCIAC) to review the operation of a sour gas processing plant in Thailand. The plant had been constructed about a year earlier by the government of Thailand and was treating a gas stream from off-shore that contained a large amount of CO₂, with a very small concentration of H₂S. My assignment was to review the operation of the plant and recommend the program for operator training and plant maintenance. My recommendations were then implemented up by the Thai company with support from PCIAC.

In 1989 I was retained as consultant in the development of the design of a gas gathering system and transmission line for a sour gas pool west of the Wildcat Hills plant. The development of this pool had been delayed until suitable treating capacity became available at a nearby plant. The Wildcat Hills plant met this requirement. The gas composition contained about 15% H₂S and about 3% CO₂. Since the transmission line from the four-well pool traversed through acreage development terrain, there was a lot of opposition to the sour gas transmission line. Many meetings were held with local acreage owners, the regulator and company representatives. Approval was granted on the condition that the entire operation of the wells, the line heaters and the safety block valves would be supervised by a radio activated supervisory and control system. This included a mass balance system, for which I wrote the software that would track the volume of sour gas in the entire pipeline system and balance it against flows in and out of the system. If a discrepancy occurred within a specified time period that exceeded a certain volume, i.e., an indication of a leak, all block valves and wells would shut down automatically.

After working as a consultant for four years, I was offered and accepted a position in January 1991 as Operations Manager for a small, privately held oil and gas company. This company had no sour gas operations. I worked out an arrangement with the company whereby I could take time off without pay to pursue my interests in sour gas. In light of the collapse of the oil price in 1986, a lot of companies had laid off staff with gray hair, i.e., senior experienced engineers. I felt there would be a demand for training new recruits in sour gas technology. This led me to develop a five-day course in sour gas operations and processing. I offered this course twice a year in Calgary for several years. When registration started to drop off due to company cutbacks for extended courses, I revised the sour gas and sulfur recovery topics to one-day presentations. I have continued this approach, and through a course provider, expanded my presentations to Houston as well. A new topic on acid gas compression and injection has been included since 1995.

In 1997 I received a contract from PCIAC to train engineers from China in Canadian sour gas facilities design and production operations. The main objective was observation of such activities in various Canadian situations. The group that arrived in Calgary consisted of five senior engineering managers and one junior engineer who was the interpreter. After I provided a couple of days of instructions on the topics, we travelled throughout the province to visit actual sour operations and held extensive discussions with engineers and managers at the different sour gas facilities for three weeks.

I resigned from the small private company at the end of January 1998, and travelled the next day to Abu Dhabi. I had done some work on sour gas for Abu Dhabi National Oil Company (ADNOC) in the previous year, and ADNOC wanted me to give short courses in sour gas operations and treatment in Abu Dhabi. My presentations were the initiation of the Sour Oil and Gas Advanced Technology (SOGAT) conferences held annually in Doha. Subsequently I was contacted by a company that organized technical training in Europe and the Middle East to provide my sour gas courses through this organization. This contact gave me the opportunity to provide such courses periodically for a few years in various cities in Europe and the Middle East. In 2001 I was retained by a local Canadian EPC company that had supplied sour gas facilities to a Chinese operating company in Sichuan province. Part of the sale condition for this equipment was that training in sour gas would be included. Initially, a group of six engineers arrived in Calgary, and I presented class training in sour gas operations, followed by field visits to different locations for actual field observations and discussions with the facility engineers. This led to a further contract with the local EPC company in the following year for three weeks of training in Chengdu, Sichuan, which consisted of a comprehensive course in sour gas property determination, well tubular selection and well completion, and the design considerations and operation of the facilities to safely produce, gather and treat sour gas, as well as sulfur recovery.

In 2008, I was retained by an EPC company in Germany to give a few days of instruction on the design considerations in sour gas facilities. This company intended to enter the bidding on the design and construction of sour gas facilities in Europe and elsewhere. As a follow-up, I was retained in 2008 to assist one of their design offices in the selection and design of a scavenger system for a slightly sour gas project.

In 2012, I was retained by a US company to assist in the development of a strategy for handling sour solution gas for their project in Kurdistan. I subsequently travelled to Irbil, Kurdistan, on behalf of the company to make a presentation to senior government officials on the options of handling and regulating sour solution gas in the country.

Beyond providing courses to the industry, my consulting work in recent years has mainly been related to the design of acid gas injection facilities. Due to the slowdown in the industry in 2015, and for personal health reasons, I decided to take my career into hibernation. Over the past sixty years of my career I have had the opportunity to publish articles on my experiences described above. The publications are listed under the final heading of my CV. This includes Chapter 5 of the SPE Petroleum Engineering Handbook, Volume III, Facilities and Construction Engineering. In the meantime, our three young boys mentioned earlier grew up and graduated with degrees in Chemical/Petroleum Engineering from the University of Calgary and pursued careers in the oil patch. Our eldest son, Robert, gifted C$ 1.3 million in 2008 to the Schulich School of Engineering at the University of Calgary to create two endowments for Edward Wichert graduate and undergraduate scholarships, as well as a home room upgrade, all of which supports many students and researchers in the Chemical and Petroleum Engineering Department at the University. This gift was subsequently matched at 60% by the Government of Alberta. My faithful and always supportive wife, Dorothy, is still at my side after more than sixty years of marriage.

Upon recovery of my health by the end of 2016, I decided to write a book on sour gas and sulfur production. The notes that I had developed and updated for my courses over the years form the basic text for the book. I hope that persons in the sour gas industry will find this book of interest and of value.