# Presentation: 486516

## Autonomous Drillingin Extreme Environments

- Gregory A. Dorais
- NASA Ames Research Center

## Outline

- Background
- Motivation
- Challenges
- Current Efforts
- Candidate Architecture

## Background

- Technical Areas

## Background: Deep-hole Drilling

- 200m+ holes regularly drilled in China in 1100’s (In 1132, 4900 brine wells were registered in Sichuan province alone)
- Xinhai well drilled to 1001m in 1835
- First steam-powered drill rig is operational in 1856
- 12,261m hole was drilled in the Kola peninsula, Russia, 1970 - 1989

## Background: Deep-hole Drilling (cont.)

- Holes are generally either drilled or cored
- Holes can be lined or left unlined. Frequently holes are only lined where needed.  Liners can be continuous or segmented.
- Motor can be located on the surface or near the bit.
- Hole diameter can be constant or reduce with depth.
- Holes can be straight or vary directionally
- Semi-autonomous directional drilling is current state-of-the art.  Such drills can follow a horizontal stratum less than 1m thick.
- A variety of sensor measurements can be made while drilling or down-hole when drilling stops

## Drilling Down-hole Science Sensors

**Gamma Ray (U,Th,K)**
**Spontaneous Potential**
**Sonic**
**Density**
**Neutron ****(scatter)**
**Photoelectric Absorption**
**Neutron Activation ****(inelastic & capture)**
**Galvanic Resistivity (laterolog)**
**Induction Resistivity **
**Nuclear Magnetic Resonance (NMR)**
**Dielectric**
**Electrical Borehole Image**
**Acoustic Borehole Image**
**Video Image**

**Open Hole (fluid filled)**
**Open Hole (“air” filled)**
**Steel Cased Hole**
**Fiberglass Cased Hole**

****

****** ****- **yes
**? - **don’t know
**X - **no

****

****

****

****

****

****

****

****

**?**

****

****

****

****

****

****

****

****

****

****

****

****

****

****

****

****

****

- X

- X

- X

- X

- X

- X

- X

- X

- X

- X

- X

- X

****

****

- X

- X

- X

- X

- X

- X

- X

- X

****

**?**

**?**

- X

- X

****

****

- Presented by Quinn Passey, Exxon-Mobil, at Mars Drilling Feasibility Workshop, D. Beaty, S. Miller, Houston, TX, 2/27/2001

## Background: Extreme Environments

- Characteristics:
- Temperature, e.g., Eros: varies -150 to 100C
- Pressure
- Gravity
- Radiation
- Stability
- Accessibility
- _Uncertainty_

## Background: Autonomy & Robotics

**Deep Space 1 spacecraft**
**Launched 10/98**
**Technologies Flight Validated:**
**Remote Agent Autonomous Control System Demonstration****(model-based, goal-oriented), included:**
**Planner/Scheduler**
**Mode Identification & Recovery**
**Reactive Executive**
**Autonomous Navigation System**

## Motivation

- Exploring Earth’s extremes doesn’t appear to have been or will be a driver of autonomous drilling technology research (much less expensive to have people nearby drill site).
- Two primary drivers are:
- Cost-efficient production holes, e.g., oil.
- Space exploration
- Moons: Luna, Europa, Titan
- Planets: Mars, Venus, Mercury
- Asteroids
- Comets

## Motivation (cont.)

- Space exploration includes:
- Astrobiology: organic molecules, extinct and extant life
- Geology: composition, physical properties, and age of strata
- Climatology: climate history and its effect on crust
- Lithospheric Rheology, e.g., volcanism, tectonics
- Search for resources, e.g., water, minerals

- Graphic from Mars Drilling Feasibility Workshop, Introduction, D. Beaty, S. Miller, Houston, TX, 2/27/2001

## Challenges

- “Extreme” is an relative term: earth vs. space extremes.  Unclear how much more difficult drilling in various space extreme environments is.
- Drill Platform mobility (multi-hole capability?)
- Small hole diameter (e.g., miniaturization of sensors)
- Low power and mass budgets (limits redundancy and backup resources & equipment)
- Cuttings removal (dry?)
- Down-force application (weight-on-bit)
- Bottom Hole Assembly Cooling
- Bit control, localization, and telemetry
- Contamination of samples and hole walls
- Core removal and sample handling; attempt to maintain core temperature and pressure

## Challenges (cont.)

- COTS autonomous control systems mostly limited to nominal operations
- Resource Management
- Low power, significantly varies during day and between days
- Limited consumables, e.g., bits
- Stuck Equipment
- Mechanical Failure
- Self-maintenance, condition-based
- Autonomous recovery
- Unknown material in strata (e.g., risk of pressurized/gaseous zones)
- Hole Instability
- Hole stabilization (e.g., liners)
- Cave-in removal

## Drilling Hole-diameter Analysis

- A commercial drilling contractor, if asked to drill a hole 5km deep in unknown terrain, would
- bring in at least 50 tons of equipment
- use a prime mover with at least 50 kW of power
- producing a hole averaging perhaps 20 cm in diameter.
- The volume of this hole would be at about 160 cubic meters
- the energy delivered to the rock face would about 50 Gj,
- equivalent to over 17 kW for 100 eight hour days of drilling.
- This is vastly more mass and power than can be landed on Mars in a near-term subsurface exploration mission.

- Presented by Brian Wilcox, JPL, at Mars Drilling Feasibility Workshop, D. Beaty, S. Miller, Houston, TX, 2/27/2001

## Comparison of Technology Challenges for Mars

- Chart from Technology Breakout Session, Mars Drilling Feasibility Workshop,  D. Beaty, S. Miller, Houston, TX, 2/27/2001

- YearDepth

- 2014 missions assume successful 2007 mission

- Key for Technology Challenge
- 1 = Greatest
- 8 = Least

## 2007 Smart Lander Mission Concept

**GUIDED ENTRY**

**HAZARD DETECTION/AVOIDANCE**

**ROBUST TOUCHDOWN SYSTEM**

**SURFACE MOBILITY**

**Conduct Significant**
**Science***
** ****Sub-surface drilling **
** ****In-situ soil/rock analysis**
** ****Atmospheric measurements**

**Demonstrate Next-Generation**
**Lander/Rover Capabilities**
** ****Global access**
**latitude range**
**surface elevation**
**rugged terrain**
** ****Accurate/safe landing**
** “****Go-to” mobility**
** ****Extended mission operations**

***No “strawman” payload yet defined, examples**
** ****of possible experiments listed**

**Approach**
** ****Strong, multi-**
**  ****disciplinary team**
**NASA centers**
**Industry**
**Universities**
** ****Early pre-project**
**  ****with extensive**
**  ****technology program**

- Presented by Sam Thurman, JPL, at Mars Drilling Feasibility Workshop, D. Beaty, S. Miller, Houston, TX, 2/27/2001

## 2007 Smart Lander/Rover Concept

** ****Target: Crater in Elysium Planitia**
** ****36.7° N Lat., 252.3° W Lon.**
** ****10 km diameter**
** ****Contains “gully” features**

**2****nd**** Generation**
**EDL System**

**N**

**1****st**** Generation**
**EDL System**

**NOTE: grid squares are 10 ******** 10 km**

- Note that lower 1/3 of image is often shadowed

**99% dispersions**
**shown**

** “****Go-to” Rover Traverse Capability**
** ****Target site chosen for safety**
** ****Rover capability employed to reach**
**  ****surface features of interest**

- Presented by Sam Thurman, JPL, at Mars Drilling Feasibility Workshop, D. Beaty, S. Miller, Houston, TX, 2/27/2001

## Pallet Landing System with Fixed Payload

- Presented by Tom Rivellini, JPL, at Mars Drilling Feasibility Workshop, D. Beaty, S. Miller, Houston, TX, 2/27/2001

## Drill Concepts for 2007 Mission

- 2m drill on Rover (low risk, mobile)
- 20m Auger Drill (med. risk)
- 20-200m Coiled Tube Drill (med. risk)
- 300-500m “Worm” drill (high risk, no core samples)

## Sample Drill Algorithm

| Step | Subset of Failure Modes |
| --- | --- |
| 1. Select target site and maximum depth | - orbiter survey data is inconclusive or not received |
| 2. Transport equipment to target site |  lander does not reach target area
- lander is damaged in transit |
| 3. Set up of power generation equipment | - actual power generated is inadequate to perform mission |
| 4. Set up communication link with ground control  | - communication link not established |
| 5. Set up equipment for drilling | - lander does not adequately anchor itself to deploy drill
- lander at a severe angle |
| 6. Deploy bottom hole assembly and drill a core sample | - bottom hole assembly becomes stuck |
| 7. Retrieve core | - hole cave-in prevents core retrieval
- core stuck in core tube |
| 8. Analyze core | - core sample is contaminated |
| 9. Repeats steps 6 – 8 as power permits until done or failure (incl. preventive maintenance) |  |
| 10. If failure, attempt autonomous recovery | - system not designed with required spare part or tool |
| 11. If failure continues, attempt teleoperated recovery | - inadequate data is collected to determine problem |
| 12. Repeats steps 6 – 8 until done or failure |  |

## Sensors for Drilling Control

- Weight-on-bit
- Rate-of-penetration
- Rotation Rate
- Bit Torque
- Temperature
- Bit Depth
- Core Length
- Bottom-Hole Assembly Lift Weight
- X, Y Translation
- 6-DOF Inertia
- Gas Pressure
- Multi-spectral Imager
- Gamma Ray
- Neutron/Density

## Candidate Architecture

- Plan Runner

- Plan/State Database

- Communication Mgr.

- System & Environment Models, Procedures, Constraints, & Heuristics

- Resources, e.g., energy, consumables

- AdaptiveControllers

- Core Handling Module Sensors & Actuators

- State/Health Estimator

- Drilling and Sample Analysis Experts

- Autonomous Drilling Management System

- Declarative/ReactivePlanners

- Core & Bore Hole Data Analysis System

- physics

- signals

- Communication Network

**Ground Control System**

**On-board Control System**

- Ground Operator

- Hole Environment

- Surface Environment

- Bottom Hole Assembly Sensors & Actuators

- signals

- AdaptiveControllers

- physics

- Principal Investigator

- Communication Mgr.

- high-level commands

- low-level commands

- state/health

- plan requests

- plans

## Reference

- _Report on the Mars Drilling Feasibility Workshop_ of February 27-28, 2001, Lunar and Planetary Institute, Houston, TX, eds. Dave Beaty and Sylvia Miller, JPL.