Chief Editor’s Message: Autumn and the basics in cooking and seismic

“Remember Your Basics, They Are Your Greatest Weapon.” Iroh, “Avatar - The Last Air Bender”

This column is a return to writing about what is going on in the industry. The main goal is to emphasize the importance of understanding the fundamentals. Learning the fundamentals and becoming comfortable with it can allow us to step out of the comfort zones and be innovative and creative.

I also wanted this article to have multi-dimensions, for each person to get something out of it and for it to be fun and whimsical too. It stretched my imagination and creativity and part of it reflects Mr. Miyagi’s type of teaching and philosophy (from Karate Kid or Cobra Kai on Netflix).

In the next sections, I talk about several topics including the autumn season, Thanksgiving, cooking and unconventional plays in Western Canada and Guyana-Suriname-French Guiana.

Dedication

Dedicated to the Iron (Fe) Lady in my life who teaches me the value of stepping beyond myself because of how she has lived her life.

Autumn

For some autumn is when they have pumpkin spice latte at Starbucks.

For me autumn is one of the most beautiful times of the year when the leaves change colour. It is a time of vibrant colours of hues of crimson, orange, yellow and red. Many come to Canada at this time to see these vibrant colours with Alberta’s Rocky Mountains being listed as one of the places to go.

Artists can be seen on the edges of lakes, or along the riverbanks painting these vibrant landscapes. In the past, many artists captured these vibrant colours and landscapes of autumns in their paintings. Some examples of famous paintings of autumn are Tom Thomson’s “The Pool” or Van Gogh’s “Landscape with trees” or Monet “Autumn on the Seine at Argenteuil.”

Why leaves change colour is due to their response to the shortened days. Photosynthesis begins to slow down in response to the change in the amount of light which leads to a reduction of chlorophyll. Chlorophyll is the pigment that supports photosynthesis and gives leaves their green colour. When chlorophyll is reduced, other pigments in the leaves begin to show or are produced (CBC, 2012).

There is also a crispness in the air, and we begin to see the sun setting earlier than during the summer day. The shadows become longer on the sidewalks and there is a melancholy as the leaves turn and fall to the ground. As it gets darker earlier each day, we know winter is coming. Most of us view autumn as the time to prepare for the cold days that are ahead where we are blanketed by snow and our rivers are iced over.

People harvest their fruits and vegetables, and some will do canning of the excess to preserve for the winter. Those with excess cucumbers may make pickles that are flavoured uniquely not just with dill but with Garlic Dill, Cinnamon, Boozy, Kool-Aid, etc.

We also had a small garden lot out by High River. We used to grow potatoes, corn, peas, lettuce, cabbage, and tomatoes there. We would go on the weekend to take care of it all summer long. We would get water from the creek nearby and carry it up the hill. Then when we picked the vegetables from the garden, we would snack on sweet peas from the pod, or have carrots.

For some autumn is a time of reflection, a time to get lost on a mountain path away from most to reflect on the passing of time especially for some of us, like me, who are now in the autumn of our life.

Threshing crews and Thanksgiving

Farmers at the end of the summer begin to harvest, which is separating the wheat from the ground and then a threshing crew comes in to separate the wheat from the chafe.

Dad used to talk about working on the threshing crew up in the Strome-Killam-Sedgewick area, Alberta. Don’t worry if you never heard of these towns, they are on Highway 19 and each one has its grain elevator. These towns are about eight miles a part, and that is the distance that you can walk there and back again in a day.

At the time all the farmers in the area came and worked together helping each other with harvesting and threshing. Many were related to each other or grew up together. The joke was if you wanted to date, you had to go to the next town over. As the men worked the fields, wives would cook for them chatting and catching up with each other. It was a time to come together as a community. At the end, they would have a big feast, and this is how Canadians got their Thanksgiving.

Thanksgiving

Few know this but the very first Thanksgiving service to be held by Europeans in North America occurred on May 27, 1578 in Nunavut. The explorer Martin Frobisher held the service after landing in Nunavut to give thanks for his safe voyage to the New World. Frobisher came to the New World seeking the elusive Northwest Passage, which Europeans thought would open up a possible trade route to Asia (Neilson Bonikowsky, 2015).

In 1879, the Canadian Parliament declared November 6 as a day of Thanksgiving, and it was celebrated as a national rather than a religious holiday. Since Remembrance Day was November 11, we would have two holidays in one week and in 1957 it was changed to the second Monday of October (Neilson Bonikowsky, 2015).

Like our American cousins we do have our football, it is called the Thanksgiving Day Classic and it tends to be a doubleheader. The biggest differences between the CFL and the NFL are CFL has three downs while the NFL has four, and the field is larger for the CFL so fewer running plays, more throwing.

Plans for Thanksgiving

When it comes to the food at Thanksgiving down south, it is sweet potato casserole, cornbread dressing, mashed potatoes, pecan pie, turkey, and wine. After the dinner, you sit around and chat with friends and family.

This year I am thinking of trying a coke baste turkey or a bourbon and brown sugar glaze.

Want to try something different. I think the sweetness will bring out the flavour of the turkey.

Cooking involves chemistry bringing different flavours together and it is like life where you need to be adventurous, willing to go out on a limb.

Life after all is a series of adventures. Some of them are good, some are not so good. Through these adventures we learn, we become better. Tend to believe that when we stop learning, we stop living.

Combining flavours – new cuisine

One of things I have been thinking about is bringing Tex-Mex together with barbecue fused with Filipino flavours. Filipinos like sweet, spicy and umami (savory-hearty flavor) flavours.

Been thinking about trying an adobo beef (which has those classic Filipino flavours) burritos or a Filipino barbecue chicken or pork taco where the meat is sweeter with a mango salsa or try a longganisa breakfast burrito.

Want to take the flavours I have been immersed in by living in Texas (especially in the Valley), being in the Philippines and the Far East Asia and bring them together.

Bringing flavours together is like in geoscience when we bring various attributes together in colour blending (RGB, CMY or HLS) to illuminate our prospect.

When I do my cooking, I want to include elements of what I have done in the past to improve what I am doing. We are truly a product of all that we have been exposed to in life.

Changing as we learn more about our world

We are changing as we learn more about our world. These changes cause our view of the world to change and allows us to be more open. For example, we tend to adopt diverse cultures easier than in the past and are more tolerant now.

Our view of the world is influenced by what is around us. We adapt or assimilate what we see that is good into our own culture. Fashion and food have definitely been influenced by culture.

Many organizations send their employees to travel so they can be exposed to diverse cultures, ideas, perspectives, and ways of doing things. They want that person to change and to grow, become better.

Change is the natural progression of things. We also change as technologies change, bringing in latest ideas about how we do things. Our concepts have evolved.

In the early days of unconventional plays management viewed them as being cookie cutter, assembly line drilling because the shale is homogeneous. With that mentality geoscience became less important and was not used in planning pads and laterals as much.

If we look at successful companies, they have changed how they drill, how they have used different tools to be able to land their horizontal in the sweetest rock, incorporated new ideas and philosophies.

Application to our work

It is fun just to try something, see what happens. Sometimes when it turns out wrong, you just must laugh. It is how we learn. Remember, “Failure is only an opportunity to begin again” (more words of wisdom from Iroh).

If you watch Chef Gordon Ramsay on “Hell’s Kitchen” or “Master Chef”, you will often see him tell a contestant that certain things mix well together, and others don’t. He passes on his years of experience as a Chef but keeps an open mind. He does let the contestant try it if he or she does not want to listen. Afterwards he asks, “did you taste it?” or he gives the contestant a spoon of it and asks, “what do you think?”

Geoscience and Engineering is just like knowing different flavours or ingredients when we cook, we discover a sense of what works well together and what does not after trying. If you are open minded you can push innovative ideas, and new concepts. Rule of thumb is if it ties to what we know such as production in an area, then it works. We can then run tests and see why it works.

Unconventionals Western Canada

Currently we are moving away from the cookie cutter approach and are realizing our unconventional plays are more complex.

In Western Canada, unconventional plays in the Deep Basin tend to be low permeability or tight sandstones that require hydraulic fracturing to create highly conductive channels which are contained within the reservoir and extending as far as possible away from the wellbore (Economides et al., 2007).

These Deep Basin plays can show Class 2, 2P or 1 AVO behaviour in our seismic data. Using this information, we can land the horizontal into the sweet spot of the sand.

Stress shadowing is an important concept we need to be aware of to keep the fractures within the reservoir zone. It is the perturbation in the surrounding stress field when we induce fractures that affects the propagation of other fractures. Stress shadowing increases the minimum horizontal stress (closure stress), and the fracture initiation pressure making the reservoir harder to fracture (Dohmen et al., 2015).

As in-zone stress increases, additional fractures will grow preferentially upward and out of zone into the overburden interval until the stress accumulates in the area above (or below) the reservoir, the fractures then begin to reform in the target zone which leads to cyclical variations in frac height for different stages along the wellbore (Figure 1) (Michael et al., 2018).

Stress shadowing is dependent upon the spacing of the frac stages. If the frac stages are too close together the stress shadowing will increase. What we have found is the induced stress in the minimum horizontal stress direction is greater than that in the maximum horizontal stress direction, and the difference between the maximum and minimum stresses is reduced (Dohmen et al., 2015).

Stress shadowing is one of the reasons why production performance does not scale up in simple increments when fracture stages are added in closely spaced completions and we could see less hydrocarbon production per stage (Dohmen et al., 2015).

When the stress difference reaches a certain point, we have the optimal conditions for creating complex fractures and communicating with natural fractures in the propagation of hydraulically induced fractures (Martin, 2018).

When a fracture is not contained within the productive zone, an excessive amount of fracturing fluid tends to be used. This has some potentially serious consequences because increased formation damage may result from excessive fluid leak-off, improper proppant placement, such as settling below the zone is possible, and excessive fracture conductivity damage can occur from having to recover extra fracturing fluid (Kry & Gronseth, 1983).

Significant difference between U.S. and Canadian companies

The significant difference between the U.S. and Canadian companies involved in the unconventional plays is Canadian companies are used to practising capital discipline because of the lack of global investment over the last 3 years (Messler, 2020).

We do know that we are in a period where there is limited capital. It is hard for companies to get loans from the bank, especially reserve-based loans when the price is so low and investors are demanding higher interest rates over government securities to hold Canadian corporate debt (benchmark bond).

Parameters for fracking

To survive under these economic conditions, we need to improve our returns on our drilling programs through:

1. Increased experience
2. Improvement in drilling
3. Changes in completion designs:
   1. Increased stage count
   2. Tighter stage spacing
   3. Longer laterals
   4. Lateral spacing
   5. Frac fluid and proppant used
   6. Soak time
   7. Flow back
   8. Multi-well pad versus parent – child wells

Notice there are a lot of variables for the completion designs. In the past, we looked at Frac databases to decide which parameters to use. These databases showed what our competitions has done and we compared it to their production.

Factors like stress shadowing affect our production and tighter frac spacings may not give us the increase in production we expect. As well, tighter lateral spacing may cause frac hits and affect production in both the parent well and the child well. There is a lot of high-quality digital field data generated by multistage fracturing operations that are fueling scientific research into hydraulic fracking and the use of machine learning so that we can understand what are the drivers of the play that will optimize our fracking and allow us to design our completions better (Mutalova et al., 2019).

To do all this we need to be moving towards using an integrated geomodel. To better understand what is occurring in the subsurface during fracking we should use Distributed Fibre Optics Sensing (DFOS) and microseismic monitoring techniques while fracking. In addition, for our reservoir engineering and estimation of our reserves we need to understand our frac job, where the fracs want to and did the induced fractures interact with the natural fracture network.

I understand that all this can add to existing costs significantly, but if we could improve our completions while minimizing costs and increase our production then we can increase our Internal Rate of Return (IRR). We can also make the business case to do this to improve our performance.

Our focus should be on the drilling of much better wells rather than the drilling of more wells. If we can put our money in drilling the best wells in terms of production, then we can lower the number of wells we need to drill in an area. We save on drilling and completion costs and if we could perfect the costs for drilling that improved well it would be a win-win. Using DFOS we have found that sometimes we are overdriving the well and we can cut back on fluids and proppant.

Building the geomodel is where we can take the fundamentals and step beyond using neural nets, machine learning, etc. I once developed an attribute that combined the lithology volume from cross plotting with a porosity volume created by a neural net. It showed our competitor had missed a sweet spot by about 150 m vertically below the TD.

This is where we take what we know about geoscience and make something that ties our production better.

Doing the same thing over and over expecting different results

Einstein insanity is doing the same thing over and over and expecting different results. It is what we are doing in the industry, the same things over and over without achieving success. We have engineers and geoscientists working independently and barely talking to each other.

One of my hopes was to have a geomodel they all could work off.

When we use frac databases and competitor information to make decisions, we need to realize that we can only theoretically achieve the same success as our competition - we are not moving forward in what we do.

There is this huge fear to be the first one to try something.

We see this with the unconventional plays in the U.S. where companies were not using the science and were just drilling horizontal wells based upon what they had designed in the software to fit the lease blocks they owned (carpet drilling). It was based upon the concept that the shale was homogeneous, and stress fields are not important, but in our work, we have discovered it is not the case and we are currently seeing issues in the returns in our production because we lack the understanding of what is happening.

We know some companies were not making enough on the return of their assets and were not operating cash flow positive so they were taking out loans and selling bonds to acquire capital to drill the next pad.

Our investors lost patience because our production was falling short. Many investors are now demanding that we be cash flow positive and that we understand the reserves we are booking: Proved Developed Producing (PDP), Proved Developed Non-Producing (PDNP), and Proved Undeveloped (PUD).

Innovative Ideas

When we look at innovative ideas, we are at times taken back how someone has taken a complex idea and simplified it. The amazing part of genius is simplicity not complexity.

The more we can simplify something, the easier we can QC something, we can ensure it is correct and have more faith in it.

Some of the most incredible ideas are the simplest. As Steve Jobs said “Simple can be harder than complex: You have to work hard to get your thinking clean to make it simple. But it’s worth it in the end because once you get there, you can move mountains.”

Marine wide azimuth acquisition and Deghosting

In the early days of marine seismic we discovered that we could change our air gun and streamer configuration easily from the configuration used for acquiring 2D to that of acquiring 3D data.

The technique that was developed utilized the concept of acquiring a series of tightly spaced 2D lines referred to as CMP lines or Common Midpoint lines. These CMP lines are halfway in-between the streamers and the source. The source alternates between starboard and port that doubles the number of CMP lines we are acquiring in one pass. This type of shooting is referred to as flip flop shooting. The shot point interval is the distance from flip to flip or twice the distance of the flip-flop interval. The inline spacing is the distance between CMP lines and the crossline spacing is half the group interval distance. Where we have an inline and crossline intersect, we have the center of a bin or a Common Depth Point (CDP). This center has X and Y coordinates related to it which we call CDP-X and CDP-Y.

We then began to realize with rugged topography and complex geological structure with severe lateral velocity variations parts of the complex structure were not imaged. When we looked at streamer data acquired in different directions around the complex structure, we began to see changes in the image. This problem became known as a “seismic wave illumination problem” and analysis was done to determine which direction would give us the best image but there were trade offs.

If we could acquire the data like we do in land seismic surveys with wide azimuths we could reduce the seismic illumination issues.

Then people began to talk about using ocean bottom cables or nodes laid out like a land survey. Nodes were easiest since they could just be dropped from a vessel but there was the issue of the seismic ghosting.

The seismic ghost causes gaps in the frequency spectrum at regular intervals and then someone produced the amazing thought about using a geophone hydrophone pair and summing them together to deghost the data.

The first time the person talked about it to the group there were snickers.

With the geophone hydrophone pair it is how we sum them together which deghosts the data, so we do not have frequency notches and we improve the vertical resolution.

For the hydrophone, the first notch is always at 0 Hz and the second notch is at frequency=(V_w/Depth Cable). If the water depth is 45 m then the second notch will occur at 33 Hz, and the third and fourth will occur respectively at 66 Hz, 99 Hz and so forth.

How this is achieved is that the geophone measures particle motion in a particular direction as a vector and thus it is sensitive to the wave direction (Al-Saleh and Nietupski, 2005).

While the hydrophone is the sum of the up-going and down-going wavefields and measures particle motion as a scalar (Al-Saleh and Nietupski, 2005).

To sum the two together requires us to calculate the right scalar, if we do not have the right scalar we will have sub-optimal results (Al-Saleh and Nietupski, 2005).

P-Z summation or summation of the geophone and hydrophone is a powerful multiple attenuation algorithm removing even free surface multiples, reduces reverberations caused by water bottom multiples and attenuates the ghost in the data (Soubarras 1996).

By doing the designature before the summation we are converting the wavelet of the geophone to that of the hydrophone. Designature rotates the “mixed” source wavelet of the airgun to minimum phase. This is done because deconvolution assumes that the incoming wavelet is minimum phase and the deconvolution rotates the wavelet so that the output is zero phase.

Not many in land acquisition and processing know about designature and we need to be careful how we apply it. We apply it to phase only. If we apply the frequency, we can band limit the data.

The PZ summation adds value to the OBC acquisition because it helps with the vertical resolution.

Changes in wide azimuth acquisition

Now we acquire 3D marine data using OBC or nodes or we can utilize streamers. With streamers we have different types of acquisition:

1. Narrow Azimuth (NAZ) which is illustrated in Figure 2 and it involves a vessel pulling both streamers and sources
2. Multi-Azimuth (MAZ) uses one vessel acquiring data as the narrow azimuth mode but acquires the survey in two or more azimuths
3. Wide Azimuth (WAZ) uses two or more vessels with at least one vessel being the source vessel and the second vessel is a source vessel. We used this type of configuration in the early 1990’s with the Geco Alpha and the Geco Marlin and it was done to shoot seismic around rigs. It is more complex than you think because both vessels need to be in the right position and the crew uses real time binning to make sure they acquire what they should
4. Full Azimuth (FAZ) combines both MAZ and WAZ principles

All of this came into being because we had to deal with specific issues illumination issues around complex geology.

Most of the time we identify a problem then we begin to develop how we are going to deal with that problem. After we develop the prototype, we start to work on how to make it economical and better functioning.

Innovative technologies marine processing

With the complex salt structures that we deal in Deep Water projects and the costs to drill we see a lot of development in imaging being down in the Deep Water projects.

The five most important advances in imaging in Deep Water data are:

1. Surface related multiple elimination (SRME) which removes the surface related multiples from the nears. Surface multiples may affect the amplitudes on the nears and cause issues in AVO analysis. SRME uses the data to derive the surface related multiples and then subtract them using adaptive subtraction.
2. Tau-p Deconvolution the multiples on the near offsets within Tau-P space occur periodically in the time domain. We utilize this with the Predictive Deconvolution which removes periodic events based upon the gap of the deconvolution. The Tau-P predictive deconvolution was designed to remove the reverberations of shallow water multiples and peg leg multiples.
3. Reverse Time Migration (RTM) is based on directly solving the wave equation in the time domain (not the frequency domain). It can accurately manage any variation in the subsurface and has no limit in imaging steep dips. It is not based on ray tracing, so it performs in situations where Kirchhoff migration breaks down.
4. Orthorhombic RTM which gives flat gathers across all azimuths which improves the stack and allows the imaging of subtle formations especially when we have FAZ data.
5. Forward Model Inversion (FWI) develops high-resolution, high-fidelity velocity model of the subsurface capable of matching individual synthetic seismic waveforms with an original raw field dataset. The high-resolution, high-fidelity velocity model create flatter gathers which create high resolution stacks and we can utilize the seismic velocity model to bring out fault behaviours and to do pore pressure work.

It is the acquisition and processing of the seismic data that has become critical to the success of the Deep Water plays. Many times, we incorporate reflective AVO attributes because we do not have the well data to do inversion work

Why talking about marine acquisition and processing

Why I wanted to talk about marine acquisition is we are seeing more oil and gas companies are considering exploring in the Deep Water than before. When the oil and gas companies made their cuts in their CAPEX, they decided to reduce their capital spending in unconventional plays like the Permian Basin.

We see major oil and gas companies looking at offshore Guyana, French Guiana and Suriname (Guyana-Suriname Basin) where they are exploring the Upper Cretaceous and Lower Tertiary basin floor fans, shelf margin deposits and turbidites directly overlying mature source that have large closure (OilNOW, 2020; Wood McKenzie, 2020).

Deep Water plays are long term investments and unlike the unconventional plays we do not have numerous operators with checkerboard leases limiting drilling potential. We need to get it right because it is costly and that means we need to believe in what we are drilling.

One of the big changes is with Floating Production Storage and Offloading (FPSO) vessels or tying back to nearby platforms so we can get products to market quicker than having to build infrastructure like we had to years ago with projects like Thunder Horse.

The growth in the FPSO market is due to the renewed focus on the development of offshore oil & gas production. The global FPSO market is expected to grow at a compound annual growth rate of more than 6.1% with South America being the largest market (Mordor Intelligence, 2020).

The most recent discovery offshore Guyana was the Liza discovery which has been evaluated at 120,000 barrels of oil per day (BOED) and they are using a FPSO vessel. The play is green field and is an integral part of ExxonMobil’s long-term growth plans (OilNOW, 2020; Wood McKenzie, 2020; Workman and Birnie, 2020).

Other offshore plays to look out for: Total & Apache’s discovery in Suriname; Brazil pre-salt; Total South Africa’s Brulpadda field (Condensate); LNG in Mozambique; Zohr in the Mediterranean off the coast of Egypt.

Importance of fundamentals / basics

To be able to make jumps in innovation we need to understand the problem and how we can apply the fundamentals or the basics to solve our issues. This means we need to become well rounded and somehow get exposure to the different branches of our science. Geologists need to be exposed to sedimentology, structural geology, rock mechanics, petrophysics, well logging, etc. Geophysicists need to be exposed to seismic acquisition, processing, rock properties, petrophysics, rock mechanics, sedimentology, etc.

We limit ourselves if we limit what we do, we need to take on projects that expand our horizons and allow us to step out of our comfort zone.

Conclusion

Our world is changing and how we do things are evolving. We need to lower our costs, maximize our production, minimize risk and do better.

We need to understand the market, what is happening and why so we can plan our future.

To do that we need to go back to the basics and from there step outwards - trying new things.

We need to do better in what we are doing, working collaboratively, and going across silos. In most oil and gas companies we have engineers and geoscientists and they report to different people. These silos also occur in the data and when we are working on a project it is best to use collective data that could add dimensionality to our geomodels.

Since we have diverse types of completions it is best to understand what was used and to be able to compare different completion techniques and their results across an area. Length of the lateral, multi-well pad versus parent-child, frac stage spacing, fluid, proppant volume, etc. all affect our completion strategies which affects our production.

Our goals need to be shared team goals about increasing our production, reducing the costs through innovative ideas and the development of new workflows that decrease our turnaround time to make decisions. It is the little things, not the big, that dramatically alter how we do things. For us it was looking at partial stacks in the Deep Basin that improved our performance.

Remember who we are is shaped by many things such as the people around us, what we read, what we take on as projects, etc.

Reading really helps us to grow and I hope these columns help you to develop.

Happy belated Thanksgiving from the RECORDER Committee to you and your family. Hopefully, you and your family are all safe and enjoyed the holiday.