Challenges of Directional Drilling while Geo-steering

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Challenges of Directional Drilling

while Geo-steering

Ali Rodriguez

▪ NAM Drilling Services Manager

– Currently working for Gyrodata Inc.

– 22 years oilfield experience

– Petroleum Engineer/Technical University

– Houston, TX

– Experience primarily in Directional Drilling

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Gyrodata

▪ Core business is Gyroscopic services

– Drop gyros

– GWD, GWD 40, 70 and 90

▪ After the downturn we have been focusing also on

directional drilling, offering:

– Conventional (Motor + MWD – Mud Pulse or EM)

– RSS (All sizes)

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Well Planning Process

▪ Customer provides:

– Geological Prognosis (Tops and TVD’s, Ground Elevation, Latitude and Longitude, etc.)

– Offsets wells for anti-collision purposes

– Survey Plat

– Well head separation

▪ Directional Company provides:

– Well plan

– Best anti-collision possible

– Engineering solutions: Torque and Drag, BHA tendencies, Recommended drilling parameters, etc.

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Survey Plat

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Survey Plat

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Geological Prognosis

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Geological Prognosis

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Well Plan

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Well Plan

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Directional challenges in the curve

Drilling the curve

▪ Kicking off well

▪ Unknown build rates

▪ Hard to hold tool face

▪ Landing the well

▪ Changes in target

▪ Tools used;

▪ Survey and GR with conventional tools are 50’ behind

▪ Mud Pulse or EM telemetry

▪ Changes in TVD and Direction

▪ Time

▪ Customers demand ROP

Build rates

Well in Wyoming

▪ Mud Motor 6/7 Lobe, 5.0 Stage, 0.29 rpg w/ 2.12 FBH

▪ Flex NMDC above MWD Collar

▪ Max Dogleg = 15.46°/100’ (M.Y. = 15.46°/100’)

▪ Predicted Build Rate = 10.32°/100’ DLS

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10200 10400 10600 10800 11000 11200 11400 11600 11800 12000

Slid

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Measured Depth

Planned Curve Dogleg Actual Curve Dogleg Slide-Rotate

Changes in TVD in the curve

Changes in TVD in the curve

Directional challenges in the lateral

▪ Geo-steering

▪ Changes in TVD and Direction

are not immediate

▪ Too many changes in well profile

cause inability to slide further in

the lateral, requiring changes in

BHA, different tools i.e. RSS, etc.

▪ Tortuosity might have been

generated in the vertical, nudge

or tangent.

Changes of TVD in the lateral

Sin 1° * 100’ =

100’

X

1°

1.751.75’

If the deviation sensor is 50’, it will take 150’ to see the change in TVD

Directional Tools used to Geosteer – Mud Motor & MWD toos

Mud ▪ Mud Motors with MWD tools

▪ Standard Gamma Ray

▪ Azimuthal Gamma Ray

▪ Pros:

▪ Reliable

▪ Cost Effective

▪ Cons:

▪ Bit to sensor distance

▪ Slide and rotate

RSS tools

Seal Assembly Seal Assembly

CompensatorActuators

▪ Pros:

▪ Quick reaction time

▪ Near bit Inc, Az and GR – Including

Azimuthal

▪ Cons:

▪ Reliability, more electronics downhole

▪ Cost ▪ Lost in Hole

Anti-rotation Pads

Near bit Inc and Gamma Ray

▪ Pros:

▪ Quick reaction time

▪ Near bit Inc, Az and GR

▪ Cons:

▪ Reliability

▪ Off the shelf tools

▪ Hardwired motors

▪ Short hub (EM)

▪ Only a lateral tool primarily due to

added bit to bend distance

Live Inc and Live Azimuth

▪ Live Inclination and

Live Azimuth help

the Directional

Driller monitoring

trends, look ahead

and react quicker.

LWD Tools

▪ Azimuthal GR

▪ Spectral GR

▪ Azimuthal Resistivity

▪ Neutron – Density

▪ Pros

▪ More data for analysis

▪ Imaging allows better interpretation

▪ Cons:

▪ Cost and LIH

▪ Still high bit to sensor distances

Conclusion

▪ Directional drilling is an exact science for calculations, however we are the mercy of the formation and tools to our disposal.

▪ Directional drillers and Geo-steering personnel need to work

very close

▪ We are drilling to maximize production and “to stay in zone”

▪ If we drill better wells working with Geo-steering personnel, our

customers will continue drilling.

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Thank You