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Improving Gas Well Drilling and Completion with High Energy Lasers

Brian C. Gahan

Gas Technology Institute

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Drilling for Oil and Gas in the US

Oil and Gas Wells Drilled, 1985-2000Exploratory and Development

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Total Footage Drilled (Oil, Gas, &Dry Holes)

Petroleum Total Wells Completed

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Average Cost per Foot

Average Depth per Well

Drilling for Oil and Gas in the US

Estimated Cost Per Foot and Average Depth Per Well of All Wells (Oil, Gas and Dry) Drilled Onshore in the U.S. from 1959 - 1999 (DeGolyer and MacNaughton, 2000)

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Drilling for Oil and Gas in the US

1990 GRI Study on Drilling Costs

Major Categories % of Total Time

Making Hole 48

Changing Bits 27

And Steel Casing

Well & Formation Characteristics 25

Total Drilling Time 100% .

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High-energy Laser Applications

Lasers could play a significant role

as a vertical boring &

perforating tool in gas well drilling

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 System Vision

Laser on surface or within drilling tubing applies infrared energy to the working face of the borehole.

The downhole assembly includes sensors that measure standard geophysical formation information, as well as imaging of the borehole wall, all in real time.

Excavated material is circulated to the surface as solid particles

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System Vision

When desired, some or all of the excavated material is melted and forced into and against the wall rock.

The ceramic thus formed can replace the steel casing currently used to line well bores to stabilize the well and to control abnormal pressures.

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System Vision

When the well bore reaches its target depth, the well is completed by using the same laser emergy to perforate through the ceramic casing.

All this is done in one pass without removing the drill string from the hole.

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Laser Product Development

LASER BASIC RESEARCH

Laser FE

Laser DrillingAssist

Laser Perf

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Off Ramp: Perforating Tool

Proposal Submitted to Service Industry Partner

Purpose– Complete or re-complete

existing well using laser energy

Requirements– Durable, reliable laser

system– Energy delivery system– Purpose designed

downhole assembly

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Preliminary Feasibility Study

Laser Drilling Experiments – 11/97– Basic Research – 2 years

Three High-Powered Military Lasers– Chemical Oxygen Iodine Laser (COIL)– Mid Infra-Red Advanced Chemical

Laser (MIRACL) – CO2 Laser

Various Rock Types Studied– Sandstone, Limestone, Shale– Granite, Concrete, Salt

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MIRACL – Simulated Perf Shot

A two-inch laser beam is sent to the side of a sandstone sample to simulate a horizontal drilling application.

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MIRACL – Simulated Borehole Shot

After a four-second exposure to the beam, a hole is blasted through the sandstone sample, removing six pounds of material.

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GRI-Funded Study Conclusions

Previous Literature Overestimated SE Existing Lasers Able to Penetrate All Rock Laser/Rock Interactions Are a Function of

Rock and Laser (Spall, Melt or Vaporize) Secondary Effects Reduce Destruction Melt Sheaths Similar to Ceramic

Study Conclusions Indicate Additional Research is Warranted

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Laser Drilling Team – Phase IGas Technology Institute

DOE NETL

Argonne National Laboratory

Colorado School of Mines

Parker Geoscience Consulting

Halliburton Energy Services

PDVSA-Intevep, S.A

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Drilling With The Power Of Light DOE Cooperative Agreement DE-FC26-00NT40917

– Original Proposed Tasks and Timeline

Quarter 3 4 1 2 3 4 1 2 3 4 1 2

Quarter 1 2 3 4 1 2 3 4 1 2 3 4Task 1. Project Structure and ManagementTask 2. Fundamental Research2.1 Laser cutting energy

assessment series2.2 Variable Pulse Laser Effects2.3 Drilling Under Insitu

Conditions2.4 Rock-Melt Lining Stability2.5 Gas Storage Stimulation2.6 Laser Induced Rock

Fracturing Model2.7 Laser Drilling Engineering

Issue IdentificationTask 3. System Design Integration3.1 Solids Control3.2 Pressure Control3.3 Bottom-hole Assembly3.4 High Energy Transmission3.5 Completion and Stimulation

Techniques for Gas Well Drilling

3.6 Completion and Stimulation Techniques for Gas Storage Wells

Task 4. Data Synthesis and InterpretationTask 5. Integration and ReportingTask 6. MilestonesTask 7.Technology Transfer

Year 3Year 2Year 1

TABLE 3: WORK TASK TIMELINES2001 2002 20032000

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First Phase (FY-01) Objectives

Accepted Phase 1 Task List1. Laser cutting energy assessment

2. Variable pulse laser effects (Nd:YAG)

3. Lasing through liquids

Quarter 4 1 2 3

Quarter 1 2 3 41.0 Project Structure and

Management

1.1 Laser cutting energy assessment series

1.2 Variable Pulse Laser Effects

1.3 Conduct Lasing Through Liquids

1.4 Topical Report

Year 1

20012000TABLE 3: WORK TASK TIMELINES

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Phase I Laser: 1.6 kW Nd:YAG

Focusing Optics

Laser Beam

Rock

7.6 cm

Neodymium Yttrium Aluminum Garnet (Nd:YAG)

1.27 cm

Coaxial Gas Purge

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Conclusions: GTI/DOE Phase I

SE for Shale 10x Less Than SS or LS Pulsed Lasers Cut Faster & With Less

Energy Than Continuous Wave Lasers. Fluid Saturated Rocks Cut Faster Than Dry

Rocks. Possible Mechanisms Include:

More Rapid Heat Transfer Away From the Cutting Face Suppressing Melting

Steam Expansion of Water Contributing to Spallation

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Conclusions: GTI/DOE Phase I

Optimal Laser Parameters Observed to Minimize SE for Each Rock Type

Shorter Total Duration Pulses Reduce Secondary Effects from Heat Accumulation

Rethink Laser Application Theory – Rate of Application: Blasting vs Chipping

Unlimited Downhole Applications Possible due to Precision and Control (i.e., direction, power, etc.)

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DOE-GTI/NGOTP-ANL Phase 2 In Progress

Continuation of SE Investigations– Effects at In-Situ Conditions – Effects of Multiple Bursts and

Relaxation Time– Observations at Melt/Vapor Boundary

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Supporting Slides Detailing Phase I Work

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Laser Cutting Energy Assessment

Measure specific energy (SE) – Limitation of variables

• SS, shale and LS samples• Minimize secondary effects

– Identify laser-rock interaction mechanisms (zones)• Spall, melt, vaporize

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Just Enough Power

Conducted Linear Tests– Constant Velocity Beam Application (dx)– Constant Velocity Focal Change (dz)

Five Zones Defined in Linear Tests Identified Zones Judged Desirable for

Rapid Material Removal– Boundary Parameters Determined for Spall into

Melt Conditions

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Laser/Rock Interaction Zones

Zone Called Thermal Spallation Judged Desirable for Rapid Material Removal

Optimal Laser Parameters Were Determined to Minimize:– Melting – Specific Energy (SE) Values– Other Energy Absorbing Secondary Effects, and– Maximize Rock Removal

Short Beam Pulses Provided “Chipping” Mechanism Comparable to Conventional Mechanical Methods

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Zonal Differences

SE differs greatly between zones Shale shows clear SE change between

melt/no melt zones Much analysis remains to understand

sensitivities of different variables

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SE vs Measured Average Power (kW)

SH11A

SH10

SH11B2

SH18A

SH12B2

SH8

SH11B1

SH13A

SH15A1

SH15A2SH12B1 SH2 SH6

R2 = 0.9095

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Measured Average Power (kW)

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Zone 3 - Significant Melt

Zone 2 - No MeltMinimum SE

Spallation

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Lithology Differences

Differences between lithologies more pronounced when secondary effects minimized

Shale has lowest SE by an order of magnitude.

Sandstone and limestone remain similar, as in CW tests

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All ND:YAG Tests

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Sandstone Limestone Shale

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SE Values: Wet vs. Dry Samples

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Atmospheric Conditions.