Category Archives: Articles

Casing Wear Series - 5: What Have We Learned?

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First of all, we realized that the data obtained from a casing wear test did not represent a single property of any one of the three elements (casing, tool joint, drilling fluid) of the casing wear system being tested.

The curve of ‘wear groove depth’ vs. ‘test time’, such as that shown in Figure 1, shows the performance of the entire casing wear system under the operating conditions of the test.

Wear Groove Depth VS Elapsed Test Time

Figure 1: Wear Groove Depth VS Elapsed Test Time

Next, we learned that casing grade, such as K-55, N-80, C-95, was not a good indicator of wear properties. Wear factors for various samples of N-80 casing were uncertain to ± 50%. Often there would be a significant difference in the wear factors obtained from casing samples cut from opposite ends of a 40 foot casing joint. Later tests showed a remarkable lack of correlation between wear factor and just about everything else associated with the composition of the casing alloy.

Every casing wear system should be regarded as unique and individual, and probably not related to any other casing wear system.

The Maurer ‘Wear Factor’, shown in Figure 2, has been shown to predict the performance of casing wear systems encountered in drilling operations with an uncertainty that is consistent with the uncertainty of the field measurements.

What is important in estimating casing wear to be expected during drilling operations is whether the casing wear factor will be 0.2 (oil based mud), 1.0 (some of the new hardbanding alloys), 5 to 8 (unprotected tool joints), or as high as 50 or 70 (X-80 as used in riser pipes).

Remember that we said that casing grade was no indicator of casing wear rate? I make an exception for X-80, a line pipe, often used as the basis for 21 inch riser pipes. At first, we didn’t believe our own results, but, yes, it was true. This explains the severity of riser wear adjacent to the flex joint at the wellhead.

Casing Wear Groove Volume VS Work Done by Tool Joint

Figure 2: Casing Wear Groove Volume VS Work Done by Tool Joint

The result of extremely high casing wear rate is shown in Figure 3. The tool joint was hardbanded with rough tungsten carbide, as shown in Figure 1 of Casing Wear Series – 1: How we got here?.

Extremely High Casing Wear Rate

Figure 3: Extremely High Casing Wear Rate

This is why rough, field applied Tungsten Carbide has largely been abandoned as a means to protect tool joints during drilling operations. It does protect the tool joints, but is a bit hard on the casing.

Glamour Dollhouse & Software Manual

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We bought a glamour dollhouse for my 6-year-old daughter for Christmas. It finally arrived a couple of days after new year of 2012.

Yesterday evening, I set up a time to assemble it with my daughter, thinking that I could demonstrate how easy the assembly would be if we read the instructions and work together. However, the installation turned out to be a trial-n-error process. At one time, I thought I had finished the dollhouse, only to find that the top floor (one of the 3) was installed upside down with unpainted side facing up. The problem was not only about aesthetic, I also couldn’t install the partition into the slot on the floor, which was the last step. In other words, I wasn’t be able to identify the problem until the last step.

It was a major frustration, because I had to uninstall half of the dollhouse to be able to flip the floor. One can argue that I am not a handyman, which I agree, but the assembly instruction, being in black and white, doesn’t differentiate some subtle differences. And what is the worst is that any mistakes during the installation do not stop one from continuing.

My daughter had to go to bed without seeing it get done for school has started. Right before she left for her room she comforted me by saying: “We could do it tomorrow.” The installation was finally completed, after 2 hours. I felt good and now I am a semi-expert in dollhouse assembly.

This morning, my daughter’s eyes sparkled when she saw this 5-ft dollhouse standing, just as the 1st time she played “Angry Bird” in iPad a few months ago. But at that time, none of our family read user’s manual of iPad. My 6-year-old learnt to play with it almost as quickly as I did.

It is an industry norm that almost anything we buy today, from glamour dollhouse or drilling software, comes with an instruction or manual. But in reality, people seldom read manual because they do not have time and/or they expect the device or software friendly enough to be figured out. Steve Jobs once commented: “The manual for WordStar, the most popular word-processing program, is 400 pages thick. To write a novel, you have to read a novel – one that reads like a mystery to most people.”

Many people do not want to spend time reading instructions. The best manual is probably the carefully designed structure and graphical user interfaces for software. If technical background is a necessity, by all means have it in user’s manual, but the explanation of how to operate software should be kept minimal for intuitive design.

For drilling software, if roughnecks on the rig and engineers in the office can both run them without going through user’s manual, one of our goals is achieved.

Casing Wear Series - 4: Interpreting Casing Wear Test Data

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Casing wear test data consists of a series of wear groove depths and the elapsed test times at which they were obtained. A data set from one such test is pictured in Figure 1.

Wear groove depth VS Elapsed test time

Figure 1: Wear groove depth VS Elapsed test time

Since it is desired to use these test results to predict the performance of casing wear systems with dimensions other than those used in the laboratory test (Different casing ID and tool joint dimensions), a model which is independent of the casing and tool joint dimensions was needed. Such a model was proposed by Dr. W. C. Maurer. His model was: The casing wear groove volume per unit length of casing is proportional to the work done per unit length on the casing by the tool joint. The constant of proportionality, called `Wear Factor’, was to be evaluated at the end of the 8 hour casing wear test, as shown in Figure 2.

Casing Wear Groove Volume VS Work Done by Tool Joint

Figure 2: Casing wear groove volume VS Work done by tool joint

Here, the performance of the casing wear system is characterized by a single number - the wear factor. This describes the performance of the casing wear system (consisting of casing, tool joint, and drilling fluid ) as linear. Obviously, this is not the case.  But, the linear model greatly simplified the development of a mathematical procedure to predict the wear performance of a wear system in the field. This was the basis for several casing wear mathematical programs which are quite successful in predicting the casing wear to be expected in field drilling operations today. The difference between predictions based on the linear wear performance system and the real world non linear system is, in many cases, less than the uncertainty of wear data obtained in the field. Casing wear logs are costly and time consuming, and are not usually run on a routine basis.

CWPRO is a modern upgraded and improved descendent of these earlier casing wear programs.

Casing wear groove geometry

Figure 3: Casing wear groove geometry

Conversion from casing wear test data, ‘groove depth vs. elapsed time’, to ‘groove volume vs. frictional work’ is a straightforward mathematical operation based on the wear groove geometry shown in Figure 3.

From ‘groove volume vs. frictional work’ back to a ‘casing wear groove depth vs. rotating time’ is similarly straightforward, regardless of the geometry in the field operations.

Knowing the value of the wear factor, and applying the concept that casing wear groove volume is a universal function of frictional work done by the tool joint on the casing, allows us to convert from wear groove volume to wear groove depth for any combination of casing internal diameter and tool joint outside diameter.  When applying the wear model to field drilling operations, the frictional work done by the tool joint on the casing is first determined. Applying the mathematical model to this information, allows the casing wear groove volume to be determined. Knowing the wear volume, and the inside diameter of the casing and the outside diameter of the tool joint (see Figure 3) we have all the information needed to determine the depth of the casing wear groove.

When the complete description of the wear system performance is needed, the differential wear factor shown in Figure 4 is used. The differential wear factor is the slope (derivative) of the wear groove volume vs. work function curve.

Differential wear factor

Figure 4: Differential wear factor

"Stay hungry, stay foolish" and other Steve Jobs' quotes

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Steve Jobs, one of the fathers of the personal computing era and the founder of Apple, died on October 5th, 2011 at the age of 56. Throughout the years, he’s not only changed our lives with innovative products, but also with his charismatic personalities as colorful as his life and management style.

His life, work and words have inspired millions. Here are some of Steve Jobs’ quotes.

“When you’re a carpenter making a beautiful chest of drawers, you’re not going to use a piece of plywood on the back, even though it faces the wall and nobody will ever see it. You’ll know it’s there, so you’re going to use a beautiful piece of wood on the back. For you to sleep well at night, the aesthetic, the quality, has to be carried all the way through.” [Playboy, Feb. 1, 1985]

“It’s more fun to be a pirate than to join the navy.” [1982, quoted in Odyssey: Pepsi to Apple, 1987]

“Being the richest man in the cemetery doesn’t matter to me … Going to bed at night saying we’ve done something wonderful… that’s what matters to me.” [The Wall Street Journal, May 25, 1993]

“Innovation has nothing to do with how many R&D dollars you have. When Apple came up with the Mac, IBM was spending at least 100 times more on R&D. It’s not about money. It’s about the people you have, how you’re led, and how much you get it.” [Fortune, Nov. 9, 1998]

“We made the buttons on the screen look so good you’ll want to lick them.” [On Mac OS X, Fortune, Jan. 24, 2000]

“You can’t connect the dots looking forward; you can only connect them looking backwards. So you have to trust that the dots will somehow connect in your future. You have to trust in something — your gut, destiny, life, karma, whatever. This approach has never let me down, and it has made all the difference in my life.” [Stanford commencement speech, June 2005]

“Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do. If you haven’t found it yet, keep looking. Don’t settle. As with all matters of the heart, you’ll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So keep looking until you find it. Don’t settle.” [Stanford commencement speech, June 2005]

“When I was 17, I read a quote that went something like: “If you live each day as if it was your last, someday you’ll most certainly be right.” It made an impression on me, and since then, for the past 33 years, I have looked in the mirror every morning and asked myself: “If today were the last day of my life, would I want to do what I am about to do today?” And whenever the answer has been “No” for too many days in a row, I know I need to change something.

“Remembering that I’ll be dead soon is the most important tool I’ve ever encountered to help me make the big choices in life. Because almost everything — all external expectations, all pride, all fear of embarrassment or failure — these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart.” [Stanford commencement speech, June 2005]

“I didn’t see it then, but it turned out that getting fired from Apple was the best thing that could have ever happened to me. The heaviness of being successful was replaced by the lightness of being a beginner again, less sure about everything. It freed me to enter one of the most creative periods of my life.” [Stanford commencement speech, June 2005]

“No one wants to die. Even people who want to go to heaven don’t want to die to get there. And yet death is the destination we all share. No one has ever escaped it. And that is as it should be, because Death is very likely the single best invention of Life. It is Life’s change agent. It clears out the old to make way for the new. Right now the new is you, but someday not too long from now, you will gradually become the old and be cleared away. Sorry to be so dramatic, but it is quite true.

“Your time is limited, so don’t waste it living someone else’s life. Don’t be trapped by dogma — which is living with the results of other people’s thinking. Don’t let the noise of others’ opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary.” [Stanford commencement speech, June 2005]

And One More Thing…

“Here’s to the crazy ones, the misfits, the rebels, the troublemakers, the round pegs in the square holes… the ones who see things differently — they’re not fond of rules… You can quote them, disagree with them, glorify or vilify them, but the only thing you can’t do is ignore them because they change things… they push the human race forward, and while some may see them as the crazy ones, we see genius, because the ones who are crazy enough to think that they can change the world, are the ones who do.” [Think Different, narrated by Steve Jobs]

Steve Jobs

The photo mosiac above was created by Charis Tsevis, a talented and creative artist/visual designer who has done work for a myriad of corporations, including Toyota, Fortune, Time, and the Los Angeles Times.  We got permission from Charis to use this artwork of his.  Thanks, Charis!  See more of his work in his website: http://www.tsevis.com

Casing Wear Series - 3: Developing an Experimental Technology

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During the 15 years covered by these Drilling Engineering Association studies, more than 450 casing wear tests were run. Each test required an elapsed test operating time of 8 hours.  Each test would be interrupted after the first 15 minutes, then after elapsed time of 30 minutes, 2, 4, 6, and 8 hours to measure the width and depth of the casing wear groove. Such a casing wear groove is shown symbolically in Figure 2, and Figure 3 is a photograph of an actual casing wear groove. Tool joint wear was measured only after the conclusion of the 8 hour test time. Intermediate measures were not possible due to the very small amount of tool joint wear - usually 0.005 inches, or less, of diametrical wear. Measurement uncertainty was estimated to be ±0.0005 inches.

Casing and Tool Joint Samples

Figure 1: Casing and Tool Joint Samples

9 5/8 inch, 47 lb/ft. N-80 casing was chosen to be the baseline standard against which wear systems would be judged. At this time ( 1991 ), N-80 casing was the most commonly used tubular in oilfield operations. The standard tool joint was machined from AISI 4145 steel, and the baseline mud system was a 10 ppg, water-based mud carrying 7% by volume of Clemtex #5 sand.

All test operations were performed manually. Several attempts to automate test operations were unsuccessful. Satisfactory precision in the recorded data could not be achieved.

The original Drilco test machine was purchased by the National Oil company of China and a duplicate copy of the machine is now being operated by Ken Malloy of Mohr Engineering. Casing wear testing is available on a commercial basis from Mohr Engineering.

Casing and Tool joint Wear

Figure 2: Casing and Tool joint Wear

Casing Wear Groove

Figure 3: Casing Wear Groove

Who was Derrick?

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Source: Cabot Specialty Fluids Limited

Tyburn-tree

Crowds gather to watch a hanging from the ‘Tyburn tree’ in 1696

The oil derrick is an industry ‘symbol’ typifying oilfields the world over. We’ve all seen them, but have you ever wondered how they got their name?

Derrick originated as a given (first) name in English and is derived from the Dutch “Diederik”, meaning ‘chief of the people’. There’s a certain irony in this, as the man who devised the first derrick was an Elizabethan Englishman by the name of Thomas Derrick, one of the country’s most famous hangmen. Not a popular profession at the time due to the threat of reprisals, many had to be coerced into the role. Derrick was convicted of rape and risked execution when Robert Devereux, the 2nd Earl of Essex, pardoned him on the condition that he become hangman at Tyburn, near the current location of Marble Arch in London.

Not content with the traditional rope over the beam method he invented a new structure using a movable beam and pulley system, and lent this new invention his name. Consequently, ‘derrick’ became synonymous with the support frame for the hangman’s noose from the 1600s and through general usage to cranes and derricks of today.

Derrick executed over 3,000 people during his prolific career, one of the most notable being his own pardoner, the Earl of Essex, for a botched coup d’état against the government of the day. Now there’s thanks for you.

Casing Wear Series - 2: The Basics

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When it became apparent that casing wear was going to be a matter to be reckoned with, several organizations initiated experimental studies of this phenomenon. Among these were (1) Shell Oil Company, (2) Exxon, (3) Texas A & M, and (4) Drilco. All these operators discovered that experimental casing wear studies were both time consuming and expensive.

All of the casings wear studies involved building a machine that would simulate field conditions as closely as possible in the laboratory. Figure 1 is a symbolic presentation of a casing wear test machine that incorporates all of the parameters needed to simulate casing wear as it would occur under field conditions.

Elements-of-a-casing-wear-test-machine

Figure 1: Elements-of-a-casing-wear-test-machine

As shown in the Figure 1, the rotating tool joint sample is pressed against the inner wall of the casing sample with a constant force. The intersection of the casing and the tool joint is flooded with drilling fluid, which contains sand to simulate the drill cuttings which the mud transports to the surface in field operations.

In addition, the tool joint ( or the casing sample ) should be slowly reciprocated during the wear test to simulate drilling progress. Failure to include this reciprocation results in a significant reduction in the observed casing wear. It is believed that without reciprocation, the casing sample and the tool joint sample will `mate’ to each other, and the drilling fluid will then form a hydrodynamic lubricating layer between the two surfaces. This will greatly reduce the grinding effectiveness of the sand that is transported by the drilling fluid. Non-reciprocating wear tests may result in as little as 10% of the wear observed in tests where reciprocation is employed.

Such a casing wear test machine is pictured in Figure 2. This machine was built by Steve Williamson ( Drilco ) in the early 1980s, and was later purchased by Maurer Engineering for use in the Drilling Engineering Association ( DEA ) projects ( DEA – 8, DEA – 42, and DEA – 137 ). These projects covered the period from 1990 through 2002.

Drilco casing wear test machine

Figure 2: Drilco casing wear test machine

Most of the material presented in these articles was developed as a result of the work done using this machine.

Torque and Drag - Nuts and Bolts

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No matter it is an operation of drilling or casing running; any pipe movement in the deviated wellbore produces torque and drag (T&D) along the pipe. T&D is our weapon to drill a well or run a casing to the bottom. However, excessive T&D will cause equipment and operation failure.

Basically, axial movements such as drilling ahead or tripping creates drag, while rotation produces torque. The magnitude of T&D is determined by the combination of these two movements. Rotation shifts the resistance from drag to torque. In other words, you can shift the drag to torque by rotating the pipe. That is why people tend to rotate the pipe little bit if pipe gets stuck.

Torque and Drag Calculation

Typical T&D analysis starts by dividing the pipe into small elements. Calculation begins from the element at the bottom of the pipe, where weight on bit (WOB) or torque on bit (TOB) is expected. For each element, force and torque are balanced and the T&D at the top of the element are calculated step by step and from bottom to top, calculation is performed for each pipe element, until it reaches the rig floor. We call the torque and drag at the top of pipe surface torque and hook load (with block weight), respectively.

Torque and drag calculationTorque and Drag Common Terms

Some terms often used in torque and drag analysis are listed here with explanations:

  • Friction Factor (F.F.) - the representation of the friction between the wellbore/casing and the work string. The friction factor is dependent on mud type, pipe and wellbore and cutting concentration. Higher cutting concentration leads to higher friction factor.
  • Rotating Off Bottom (ROffB) – pipe rotates without any axial movement, such as rate of penetration or tripping. There is no WOB or TOB because bit is not engaged with formation.
  • Rotating On Bottom (ROnB) – pipe rotates without any axial movement, such as rate of penetration or tripping. However, WOB and TOB are present because bit is engaged with formation.
  • Drilling – pipe rotates with certain rate of penetration and with the presence of WOB and TOB.
  • Slide Drilling - Drilling with no drill string rotation. (only axial movement, no rotation)
  • Sinusoidal Buckling - Sinusoidal buckling occurs when compressive forces on the string become too high, resulting in a snake-like bending in the string. Note that in this mode, the pipe deforms, but still in a 2D plan.
  • Helical Buckling - a more extreme form of buckling which occurs when compressive forces pass through sinusoidal buckling and exceed the helical buckling limit. Helical buckling causes contact between the pipe and the wellbore, exerting force on the wall of the hole. Both drill string fatigue and interference with weight transfer to the bit occur. Helical buckling should be avoided.
  • Helical Lockup - Helical lockup occurs when compressive forces on a string in helical buckling prevent axial movement. Forces at surface are not transmitted to the bit.
  • Tension Limit- The tension limit of a material is based on its yield strength, which is measured in psi. When the minimum yield strength is exceeded, pipe will plastically deform. Plastic deformation occurs when pipe that has stretched does not return to its original shape.
  • Make Up Torque- The rotational force used to make up a connection in the string. Drill pipe failure may occur when the make-up torque of a connection is exceeded.Buckling-Tension-Torsion
  • Stress in the String - The various stress that TADPRO models are axial, bending, torsional, and shear stresses. These stresses are summed up in the Von Mises Stress. Various failures occur as a result of repeated stress to a string, including cracking, washouts, and twist offs, etc.
  • Stress in the String - The various stress that TADPRO models are axial, bending, torsional, and shear stresses. These stresses are summed up in the Von Mises Stress. Various failures occur as a result of repeated stress to a string, including cracking, washouts, and twist offs, etc.
  •  Casing Wear- Prolonged, repeated axial and rotational movement within casing will wear both at the string and the casing, potentially leading to string and casing failure.Casing wear

Casing Wear Series - 1: How we got here?

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Prologue

Mr. Gefei Liu, president of Pegasus Vertex, Inc. (PVI), suggested that I write a series of short articles to discuss the empirical science of casing and riser wear. PVI incorporates this technology in their computer program – ‘CWPRO’. This program applies wear technology to predict casing and riser wear to be expected during drilling operations.

The observations and opinions expressed in these articles are based on my 20-year association with the subject of casing and riser wear. Much of this time was spent at Maurer Engineering, under the direction of Dr. W. C. Maurer. Much of the advances in the subject were the direct result of Dr. Maurer’s phenomenal knowledge of and insight into the technical challenges that were encountered during the development and application of casing and riser wear technology.

In the beginning

Casing wear was not recognized as a problem until the early 1960s. Vertical wells were being drilled deeper, and directional wells were being pushed out further. This required longer drilling times, and resulted in much greater exposure of the inner wall of the intermediate casing to the rotating tool joints of the drill string. Wear grooves appeared in the intermediate casing and progressed from noticeable to serious.

Up to this time, tool joint wear was the only wear problem being treated.

The universally accepted treatment to prevent tool joint wear was to coat the tool joints with an alloy containing tungsten carbide particles. This protected the tool joints, but was proving to be a bit hard on the intermediate casings.

Tungsten carbide coated tool joint (Field Applied)

Figure 1: Tungsten carbide coated tool joint (Field Applied)

The tungsten carbide coated tool joints were efficiently machining wear grooves into the inner walls of the intermediate casings. As these wear grooves deepened, they would seriously reduce the pressure capacities (burst & collapse), sometimes resulting in catastrophic failure.

Pressure test of worn casing

Figure 2: Pressure test of worn casing

These early findings resulted in the establishment of two distinct, but related, developments.

1. Experimental studies of casing wear; and

2. The development of casing-friendly tool joint coatings that would also protect the tool joints.

First of all, what are the basic elements of casing wear?

If boreholes were straight, casing wear would be much less of a problem. But, boreholes are not straight. As shown in Figure 3, tension in the drillstring pulls the rotating tool joints into the convex sides of the curved borehole. Since the tension in the drillstring may be several hundred thousand pounds force, the lateral loads forcing the tool joints into the convex wall of the intermediate casing may be several thousands of pounds force. The greater the curvature of the borehole, measured as `dogleg severity’, the greater will be the lateral load pushing the drill string into the intermediate casing wall. ‘Dogleg Severity (DLS)’, which is measured in degrees per 100 feet, can run as high as 5 deg/100 ft. or worse.

Drilling fluid which transports drill cuttings to the surface, flows past the tool joint/casing contact, and provides the abrasive needed to grind a wear groove into the inner wall of the intermediate casing.

Casing wear at a dogleg is shown in Figure 3, and a schematic of the resulting casing wear groove is shown in Figure 4.

The existence of the casing wear grooves indicates that there are many locations where epicyclic drillstring vibrations do not occur.

Elements of casing wear

Figure 3: Elements of casing wear

Casing wear groove

Figure 4: Casing wear groove

 

Calgary - a beautiful oil city to be explored

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According to the 2011 annual ranking of the most livable cities in the world, compiled by the Economist Intelligence Unit, Calgary is the 5th place in the list. Vancouver remains the most livable city in the world.

The ranking scores 140 cities on 30 factors spread across five areas: stability, health care, culture and environment, education, and infrastructure. These numbers are then weighted and combined to produce an overall figure. Seven of the top ten cities are in Australia and Canada. Harare, the capital of Zimbabwe, is in 140th place. Somewhere between the extremes sit London and New York in 53rd and 56th places.

This list definitely makes all those folks in Calgary proud. A little bit surprised (pleasantly), I myself was happy to see it in the top 5, as it is also one of my favorite cities in the world, from both business and pleasure points of view.

Doing business in the oil and gas section of Calgary is easy because majority of oil and service companies are located within 10 by 10 blocks of downtown. These offices all have  “T2P” in their zip codes and most of them are all connected by the Plus 15 or +15 skyway network, the world's most extensive pedestrian skywalk system with a total length of 9.9 miles and 59 bridges. The system is so named because the skywalks are approximately 15 feet above street level.

Because of the closeness of those companies in downtown, they do not use post masters for mails or packages. They use bicycle messengers (aka bike couriers). Courier companies use bike messengers because bicycle is less subject to unexpected holdups in city traffic jams, and is not deterred by parking limitations, fees or fines in high density development.  Benefits include environmental friendly business, predictable delivery time, etc.

We have been enjoying business association with quite a few companies in Calgary and Edmonton. Personally, I like Calgary so much that I found all excuses to visit the city.

Houston is too flat. As Mr. Jim Dech, one of our folks in Maurer Engineering 15 years ago, said: “If you stand on a can of Coke, you see everywhere.” Calgary is just the opposite, as it is located in an area of foothills and prairie, approximately 50 miles east of the Canadian Rockies. One could actually live in the Mountain and commute to work every day.

For me, not many things excite me more than driving to the Mountains after business meetings in Calgary and immersing myself in the beauties of mountains, lakes and hot spring.  Banff, Sulphur Mountain, Lake Louise, Jasper, etc. remind me one of a whole new world different in everyway from Houston. As the railroad builder William Cornelius Van Horne said, “If we can’t export the scenery, we’ll import the tourists.”

Once I became one of the imported tourists, Calgary has become one of my favorite cities.

Allow me to share some of the pictures taken in my previous trips.

Jasper - Fairmont

Lake Louise

Lake Louis