DANIEL W.H. SU CONSOL ENERGY INC. CANONSBURG, PA

GROUND CONTROL RESEARCH ? -GROUND CONTROL ENGINEER? -WORTH ONE’S SALT ? -WORTH THE EFFORT ? GROUND CONTROL RESEARCH AT CONSOL ENERGY SUCCESSFUL APPLICATIONS TO CONSOL’S MINING OPERATIONS

 COAL PILLAR DESIGN  SURFACE SUBSIDENCE  HORIZONTAL STRESS IMPACT  FLOOR BEARING CAPACITY  LONGWALL FACE SUPPORT DESIGN  HYDRAULIC FRACTURING OF MASSIVE SANDSTONE  SANDSTONE STABILITY UNDER DEEP COVER  ROOF GEOLOGY RECONNAISSANCE  INNOVATIVE ROOF SUPPORT CONCEPTS

STRESS MEASUREMENTS USING 3D BOREHOLE DEFORMATION GAGE STRESS MEASUREMENTS USING MINIFRAC STRESS MEASUREMENTS USING HYDRAULIC FRACTURING IMPACT OF HIGH HORIZONTAL STRESS ON MINING OPERATIONS HS CONCENTRATION – CSIRO HI CELL PILLAR DESIGN MODIFICATION RIGHT-HAND VS. LEFT-HAND LONGWALL

POCAHONTAS #3 SEAM -MAX HORIZONTAL STRESS: 2970 PSI(N55E) -MIN HORIZONTAL STRESS : 2090 PSI PITTSBURGH SEAM -MAX HORIZONTAL STRESS : 4300~5000 PSI(E-W) -MIN HORIZONTAL STRESS : 3400 PSI ILLINOIS #6 SEAM -MAX HORIZONTAL STRESS : 2000 PSI(E-W) -MIN HORIZONTAL STRESS : 800 PSI

DETERMINE STRESS ORIENTATION AND MAGNITUDE FORECAST ROOF CUTTER DEVELOPMENT DEFINE RIGHT-HAND AND LEFT-HAND LONGWALL PANELS PILLAR DESIGN MODIFICATION TO MITIGATE HORIZONTAL STRESS IMPACT USE OF CABLE BOLTS AND INNOVATIVE STANDING SUPPORT TO MITIGATE HORIZONTAL STRESS IMPACT

TO PROMOTE CAVING OF THICK, MASSIVE SANDSTONE TO IMPROVE FACE CONDITIONS INDUCED HORIZONTAL FRACTURES FACE MONITORING AND NUMERICAL MODELING CONFIRMED THE EFFECTIVENESS

Uniaxial Compressive Strength10,000 psi Indirect Tensile Strength1,000 psi Young's Modulus2,000,000 psi Poisson's Ratio0.25 Internal Friction Angle38 degrees In-Situ Horizontal Stresses Maximum Horizontal Stress Magnitude Orientation 5,200 psi East-West Minimum Horizontal Stress Magnitude3,500 psi Depth of Cover800' – 900' Vertical Stress Magnitude1,000 psi Estimated Mechanical Properties of Pittsburgh Sandstone

BENDING STRESS,PSI SANDSTONE SHALE BENDING STRESS DISTRIBUTION AT THE FACE WITHOUT FRACING +420 COAL

BENDING STRESS,PSI SANDSTONE SHALE COAL BENDING STRESS CONTOURS AT THE FACE WITH ONE FRAC

Longwall Panel Total Time Lost Due to Bad Top at the Face (Minutes) Average Distance of Longwall Advance/MS (Feet) B1230, B133, B143, Comparison of Production Downtime and Average Face Advance for the B12, B13, and B14 Faces within the Sandstone Channel Interval

INITIATED IN THE EARLY 90’S CONDUCT ROOF SCOPING USING FIBERSCOPE, GAMMA LOGGER AND BOREHOLE CAMERA GUIDE MINE PLANNING DECISION GUIDE DAILY ROOF SUPPORT PRACTICES IMPROVE ROOF STABILITY MINIMIZE LONGWALL MOVE DELAYS REDUCE ROOF FALL FREQUENCY UP TO 80%

SAFETY COMPLIANCE CONTINUOUS IMPROVEMENT PRODUCTIVITY COST WORTH ONE’S SALT WELL WORTH THE EFFORT

QUESTIONS ?