64
1 You have seen some great technologies and technological innovations here today. Nail guns are also a great technological innovation. They can significantly improve a carpenter’s efficiency. However, if you place a nail gun on a table, nothing happens.

Bob Shoup - Nail Guns Do Not Build Houses

Embed Size (px)

Citation preview

Page 1: Bob Shoup - Nail Guns Do Not Build Houses

1

You have seen some great technologies and technological innovations here

today. Nail guns are also a great technological innovation. They can

significantly improve a carpenter’s efficiency. However, if you place a nail

gun on a table, nothing happens.

Page 2: Bob Shoup - Nail Guns Do Not Build Houses

2

You need a carpenter to use the nail gun to build the house. The carpenter

could use a hammer, but the nail gun is more efficient

Page 3: Bob Shoup - Nail Guns Do Not Build Houses

3

Workstations are great technological innovations, they can significantly

improve an interpreter's efficiency. However, if you place a workstation on

a table, nothing happens.

Page 4: Bob Shoup - Nail Guns Do Not Build Houses

4

You need a geoscientist to use the workstation to define the subsurface

geology to find oil and gas. They could use paper sections and colored

pencils, but the workstation is more effective.

Page 5: Bob Shoup - Nail Guns Do Not Build Houses

However, many geoscientists today rely solely on their workstation

to find oil and gas for them. They use the workstation to auto

correlate, to highlight amplitudes, AVO, and attribute anomalies, and

to make their maps and calculate their reserves.

Page 6: Bob Shoup - Nail Guns Do Not Build Houses

Here is an example of a map made by a geoscientist who relied on the

workstation and not their understanding of geology.

The prospect, seen in this investor presentation found on the SEC

website, is for a fault propagation fold in the Malataya Basin of

Turkey. The map was constructed in the workstation from a grid of 2D

data. The mapped horizon is the blue event highlighted with the arrow.

6

Page 7: Bob Shoup - Nail Guns Do Not Build Houses

Based on this map, would you invest in the prospect?

7

Page 8: Bob Shoup - Nail Guns Do Not Build Houses

Before you decide to invest, lets look at the Windjammer discovery

in the Rovuma Basin of Mozambique. The Windjammer discovery

was drilled in a fault propagation fold, similar to that seen in our

investment opportunity.

8

Page 9: Bob Shoup - Nail Guns Do Not Build Houses

The Windjammer well encountered three pay zones; one in the

Miocene, a second in the Oligocene, and a third in the Paleocene.

The Miocene and Paleocene pays are stratigraphically trapped. The

Oligocene pays are structurally trapped in the core of a fault

propagation fold.

9

Page 10: Bob Shoup - Nail Guns Do Not Build Houses

Coming back to our investment opportunity, we can see amplitudes in the

core of the fold in line 1, similar to the Oligocene pays seen in the

Windjammer well.

With Windjammer as an analog, would you invest?

10

Page 11: Bob Shoup - Nail Guns Do Not Build Houses

Since the prospect consists of a fault propagation fold, perhaps we

should look at a fault propagation fold before we decide to invest. This is

a Google Earth image of the Sheep Mountain Anticline, a fault

propagation fold on the flank of the Big Horn Basin.

I have overlain some contours so we can see what the map pattern is for

a fault propagation fold.

11

Page 12: Bob Shoup - Nail Guns Do Not Build Houses

Fault Propagation Folds are asymmetric folds. The back limb of the

fold will exhibit a relatively low dip rate that will be constant and

will have the same dip as the fault surface, which for Sheep

Mountain is between 30 and 45 degrees.

The front limb of the fold will exhibit much steeper dip, and may be

overturned . The front limb of the Sheep Mountain Anticline is

almost 80 degrees.

12

Page 13: Bob Shoup - Nail Guns Do Not Build Houses

Coming back to our prospect in the Malatay Basin. Look again at the

map. Do you see any dip on the front limb of the fold?

13

Page 14: Bob Shoup - Nail Guns Do Not Build Houses

Whatever contouring algorithm the interpreter used, it did not

contour the dip on the front limb of the fold. The map is wrong, and

you should not invest, at least until you have re-contoured the map

and re-calculated the reserves.

14

Page 15: Bob Shoup - Nail Guns Do Not Build Houses

There is no question that technology has made our workflow more

efficient. Technology has also made it easier for us to see things in

the data that we could not see before. But has it really improved our

ability to make money?

Let s take a moment and go back in time to see how technology has

impacted our industries success.

15

Page 16: Bob Shoup - Nail Guns Do Not Build Houses

We will go back to the early 1980s. In the early 1980 we were pre-

email and pre-internet. Computers were capable of running

spreadsheets but little else.

Workstations at this time consisted of a drafting table, colored pencils

and erasers.

Our number one exploration tool was our ability to think about the

geology we were interpreting.

16

Page 17: Bob Shoup - Nail Guns Do Not Build Houses

In the early 1980s geoscientists hand-interpreted their seismic, hand-

correlated their wells and hand contoured their maps, forcing them to

fully understand the geology of their area and their prospect

During that time, the industry average exploration success rate was

just under 25%. In the Gulf of Mexico, it was ~22%.

17

Page 18: Bob Shoup - Nail Guns Do Not Build Houses

But in the 1980s, industry began to increasingly use seismic bright

spots to define prospects. Now geoscientists need only to find and

delineate an anomalous amplitude and drill it.

With industry drilling bright spot defined prospects, our exploration

success rate jumped up to just over 25%, in other words, no real

improvement.

18

Page 19: Bob Shoup - Nail Guns Do Not Build Houses

What the industry came to learn is that by focusing on seismic bright

spots to define prospects, we got away from understanding the

geology of our prospects. We also came to learn that bright spots can

be caused by many things other than commercial accumulations of

oil and gas.

19

Page 20: Bob Shoup - Nail Guns Do Not Build Houses

In the late 1990s, industry began using Amplitude Versus Offset to

define prospects. AVO is a fluid discriminator, so it can help

differentiate hydrocarbons from water. Now geoscientists need only

to find and delineate an AVO anomaly and drill it.

With industry drilling AVO defined prospects, our exploration

success rate jumped up to approximately 30%, a slight increase, but

hardly the “magic bullet” that many managers had hoped for.

20

Page 21: Bob Shoup - Nail Guns Do Not Build Houses

We soon came to learn that AVO anomalies can be caused by many

things other than commercial accumulations of oil and gas. And,

again, by focusing on technology rather than the geology, we drilled

many avoidable dry holes, which is the same mistake we made with

bright spots.

21

Page 22: Bob Shoup - Nail Guns Do Not Build Houses

Today, we have seismic inversion and attribute volumes. We have

incredibly robust software that allows interpreters to identify porosity

and anomalous areas and to map leads and prospects at the push of a

few buttons.

So with industry drilling prospects defined by the computer, our

exploration success rate has now jumped up to 30%, in other words,

there has been little to no change in our industry average success rate

with technology.

22

Page 23: Bob Shoup - Nail Guns Do Not Build Houses

I suspect that sooner or later we will come to realize yet again that

focusing on technology rather than the geology will cause us to drill

unnecessary dry holes.

That is because technology does not find oil and gas, interpreters do.

Just as nail guns do not build houses, carpenters do.

23

Page 24: Bob Shoup - Nail Guns Do Not Build Houses

For a geoscientist to be successful, we must make accurate reserve

estimates. If we underestimate reserves, then we can cause our

company or investor to not drill potentially economic wells. If we

overestimate reserves, we can cause our company or investor to drill

non-economic wells.

Less than 15% of the worlds geoscientists are highly successful, that

is, achieve a drilling success rate above the industry average.

24

Page 25: Bob Shoup - Nail Guns Do Not Build Houses

Those geoscientists that do have above average drilling success rates

shared 10 habits which are geologic best practices.

See https://www.scacompanies.com/the-ten-habits-of-highly-

successful-oil-finders/

25

Page 26: Bob Shoup - Nail Guns Do Not Build Houses

In a 2005 talk to the Houston Geologic Society Cindy Yeilding (BP)

posed the question “Are Workstations Killing Geology?” She noted

that our mapping packages allow us to make good looking maps but

they are often inaccurate, and that we make bad maps faster than

ever. She then pointed out that those inaccurate maps cause us to drill

“dumb” wells or unnecessary and avoidable dry holes.

She posed several additional questions including regarding our over-

reliance on the workstation:

Are all geologic views best displayed on a 20” monitor? (NO)

Do we spend too much time displaying our interpretation than

thinking about it? (YES)

Is the philosophy of seismic to simulator flawed? (Absolutely)

26

Page 27: Bob Shoup - Nail Guns Do Not Build Houses

Moreover, many geoscientists are relying more on the workstation

that their own skills and geologic knowledge. Many interpreters

today have never hand-contoured a map or made a cross section, nor

are they aware of the proper methods or structural models necessary

to make valid interpretations. Increased reliance on auto-picking for

interpretations delegates the interpretation to the computer.

Page 28: Bob Shoup - Nail Guns Do Not Build Houses

The reason workstations cause dry holes is that as interpreters

become more dependent on the technology they are losing their

geologic skills. We are observing that the workstations are doing to

geologic skills what the calculator has done to math skills

28

Page 29: Bob Shoup - Nail Guns Do Not Build Houses

So just how bad are our math skills?

Just how bad was demonstrated when a group of high school students

were given calculators programmed to give wrong answers for use in

a simple math test.

Page 30: Bob Shoup - Nail Guns Do Not Build Houses

Almost all of the students turned in tests with all wrong answers,

mostly quite obviously wrong. The students were asked if they

noticed anything wrong? There answer was yes, but since the

calculator said this was the answer, that it must be, even though they

‘felt’ that the answer was wrong.

Page 31: Bob Shoup - Nail Guns Do Not Build Houses

Our comfort with the workstation has made us complacent, and we

now tend to accept what comes out of the workstation without

question, even when it is wrong.

Page 32: Bob Shoup - Nail Guns Do Not Build Houses

32

So it is important for interpreters to use the workstations as a tool to

interpret the data. For those of you who rely on the workstation to interpret

the data, you need to be aware of how the computer sees the data

Page 33: Bob Shoup - Nail Guns Do Not Build Houses

33

When geoscientists look at this line, they should see a rift basin with

some minor inversion. As a geoscientist, you can develop a

familiarity with rift basins which you can use to predict where the

source rocks were deposited, where the reservoirs were deposited,

and where hydrocarbons will migrate

Page 34: Bob Shoup - Nail Guns Do Not Build Houses

34

When a computer looks at this line, it sees digits, So a computer can

not make geologic interpretations, it makes statistical correlations. A

computer cannot develop a familiarity with rift basins nor can it

predict anything.

Page 35: Bob Shoup - Nail Guns Do Not Build Houses

35

Before a carpenter builds a house with a nail gun, he needs to know what a house

looks like and he should know how to build it if he only had a hammer

Page 36: Bob Shoup - Nail Guns Do Not Build Houses

36

Likewise, before a geoscientist uses a workstations to interpret a prospect,

they should know the geology of the area that they are interpreting. They

should also know all of the methods and techniques needed to fully

evaluate the subsurface and to make accurate maps.

Page 37: Bob Shoup - Nail Guns Do Not Build Houses

Lets look at a case study where reserves were added to a field simply

by the construction of a geologic cross section.

37

Page 38: Bob Shoup - Nail Guns Do Not Build Houses

38

The 9300 Foot Sand in a field producing from multiple reservoirs was an

under-producing reservoir. The 9300 Foot Sand was completed in well #10

and produced about 12,000 BO. The well was estimated to have been able to

produce over 500,000 BO. Well #4 produced gas and rapidly pressure

depleted.

The 9300 Foot Sand was abandoned for several years until a new study of the

field has done. It was recognized that based on this map that there was a

material balance problem for the 9300 Foot Sand.

It was also recognized by the young geologist doing the study that no cross

section had been constructed for this reservoir.

Page 39: Bob Shoup - Nail Guns Do Not Build Houses

39

In doing the new study the geologist constructed a correlation cross

section to study the reservoir in greater detail. You can see that wells 3

and 4 encounter a thick channel sand. Wells 7 and 10 encounter overbank

or crevasse splay deposits The low production from well 10 was from the

crevasse splay sands.

The gas production was from the transgressive sand capping the

sequences. The main channel sand had not been produced.

Page 40: Bob Shoup - Nail Guns Do Not Build Houses

40

Now that the review team had a new depositional model, they constructed a Log

Facies map from the regional wells. We can see from that map that the field was

situated in one branch of the channel system

Page 41: Bob Shoup - Nail Guns Do Not Build Houses

41

The review team then constructed a net pay isochore for the channel sand and

recognized two possible channels in the field, one in the central portion of the field, and

another on the western margin of the field.

Page 42: Bob Shoup - Nail Guns Do Not Build Houses

42

The team then constructed a net pay isochore for the channel sand. The volume potential

in the western branch of the channel were too small to develop.

The central channel was determined to have approximately 4 million barrels of

recoverable reserves remaining. Well 4 was re-completed in the channel sand and found

near-virgin pressures.

Page 43: Bob Shoup - Nail Guns Do Not Build Houses

That example is not the only example of finding additional

reserves by constructing a cross section.

43

Page 44: Bob Shoup - Nail Guns Do Not Build Houses

44

In this case, the operator had produced this field for a number of

years, recovering ~ 1.5 MMBO from the oil rim. They were now

ready to blow down the gas cap.

Before granting the operator approval to blow down the gas cap, the

regulatory agency wanted proof that the oil rim had been fully

produced.

In compliance with the regulatory agency's request, the operator

conducted a complete geological study of the reservoir, including

construction of a correlation cross section

Page 45: Bob Shoup - Nail Guns Do Not Build Houses

45

The correlation Cross section showed that there was a thick incised valley sand

in wells 12, 17, and 3. Wells 12 and 17 were in the gas cap and well 3 was

below the water level

Incised valley sequences are rarely in communication with the sequence they

incise so it was considered unlikely that this incised valley sequence had been

produced.

Page 46: Bob Shoup - Nail Guns Do Not Build Houses

46

The review team developed 2 different incised valley interpretations. With interpretation

1, the incised valley crossed the field from northeast to southwest and had a volume

potential of 3.5 MMBO

Two locations were proposed for testing this interpretation. If the first well

encountered the incised valley, they would drill the second proposed well.

Page 47: Bob Shoup - Nail Guns Do Not Build Houses

47

In the second interpretation, the incised valley missed the oil rim. However, the re-

mapping showed that there was an additional volume potential of 1.5 MMBO remaining

in the oil rim. If the first well did not encounter the incised valley sequence then they

would not drill the second of the two proposed wells.

Page 48: Bob Shoup - Nail Guns Do Not Build Houses

48

The first of the two proposed wells encountered the incised valley sand as

predicted in interpretation 1, so the second proposed well was drilled The

incised valley sequence was found to be thicker than originally thought such

that the final reserve add was 4.5MMBO

Page 49: Bob Shoup - Nail Guns Do Not Build Houses

If you are not constructing cross sections you do not understand the

distribution of the fluids or the nature of the reservoir. If you do not

understand those, you are most likely leaving reserves behind.

Looking at this cross section, one can see that in the uppermost sand

of the eastern fault block the perforations (purple rectangles near the

depth track) are near the water level, leaving significant attic

reserves.

49

Page 50: Bob Shoup - Nail Guns Do Not Build Houses

The time to construct a cross section and interpret varies from a few hours to

a few days, depending on how complex the geology is. Finding additional

reserves with that cross section is priceless.

50

Page 51: Bob Shoup - Nail Guns Do Not Build Houses

We will look at another best practice, constructing a fault surface

map and integrating that map with the horizon map to define the fault

traces in their proper position

51

Page 52: Bob Shoup - Nail Guns Do Not Build Houses

This field has been producing for several years, at which time the

company sold the field along with several other assets. The field,

mapped with 3D seismic and well control, consists of a three-way

fault closure against a large growth fault. In addition to the producing

fault block, a prospective fault block had been identified and mapped

to the north of the producing fault block.

The original interpreters had not made a fault surface map. They had

simply picked faults on the seismic and posted a fault polygon.

52

Page 53: Bob Shoup - Nail Guns Do Not Build Houses

Since the original operator had never made a fault surface map, one

of the first things the new operator did following the purchase of the

field was to construct a fault surface map and integrate it with the

horizon map.

The fault surface map was constructed from the 3D data as well as

the fault picks in the wells. The data posted by the wells is the

amount of missing section (Vertical Separation) observed in the wells

and the depth of the fault.

53

Page 54: Bob Shoup - Nail Guns Do Not Build Houses

When the producing horizon was integrated with the fault surface

map, the position of the fault traces shifted to the east, opening up

approximately 400 acres of additional closure; adding almost 20

BCF of recoverable reserves.

54

Page 55: Bob Shoup - Nail Guns Do Not Build Houses

In addition to finding additional reserves by constructing fault

surface maps, we can also use them to avoid drilling dry holes.

55

Page 56: Bob Shoup - Nail Guns Do Not Build Houses

56

Here is a structure contour map generated with 2D seismic. Is it geometrically valid?

Since we are dealing with a 2 dimensional map that is portraying a 3 dimensional

surface, it takes more understanding, investigation, and analysis to identify geometric

problems.

Page 57: Bob Shoup - Nail Guns Do Not Build Houses

57

The prospect was drilled and the result was a dry hole Let’s examine the trapping fault:

The amount of offset along the trapping fault decreases from east to west. The offset

then increases again but the sense of throw is to the north, or up-thrown direction. There

is almost no offset at the well location

This is a screw fault. Screw faults CANNOT occur in compressional or extensional

faults (Scissors fault can occur with strike-slip faults). Therefore, the map portrays a

structure that is geometrically, and geologically, impossible.

Page 58: Bob Shoup - Nail Guns Do Not Build Houses

58

We call fault interpretations like this “Screw Faults” since the change in the

direction of the direction of offset of the fault makes it appear as if the fault is

screwing itself through the section. We also call the screw faults because if you drill

a well in a prospect set up by a screw fault, you are screwed.

Page 59: Bob Shoup - Nail Guns Do Not Build Houses

59

Screw Faults indicate 2 faults have been mapped as 1 fault. This is a result of the

interpreters picking fault sticks and using them to post a fault polygon as opposed

to mapping the fault.

The failure to map the fault surface results in the company drilling an unnecessary

and avoidable dry hole.

Page 60: Bob Shoup - Nail Guns Do Not Build Houses

Screw fault interpretations are very common in our industry. So common

that we can see a screw fault in the Petrel User Manual.

Page 61: Bob Shoup - Nail Guns Do Not Build Houses

If the interpreter had constructed a fault surface map it would have

been immediately apparent that the interpretation of the fault as a

single fault was geometrically and geologically impossible.

A fault surface map takes only a few hours to construct. The failure

to map the fault surface cost this company $5.5 million dollars.

61

Page 62: Bob Shoup - Nail Guns Do Not Build Houses

Technology makes our workflow much more efficient. And, it can

help us to find and better develop oil and gas.

62

Page 63: Bob Shoup - Nail Guns Do Not Build Houses

But ONLY, if we use it as a tool to help us understand the geology of

our prospects and fields.

If we use technology to replace our thinking and our knowledge of

the petroleum system, we will continue to drill unnecessary and

avoidable dry holes.

63

Page 64: Bob Shoup - Nail Guns Do Not Build Houses

For no matter how robust technology becomes, oil is first found in

the mind. Technology is nothing more than a tool to help the mind

find it.

And nail guns are just a tool to help carpenters build houses

64