User Manual - Bever Control AS

Bever Team 3Penetration rate is the major response parameters of hardness that indicates how hard the rockis to drill. Our algorithm has these steps in our current implementation:Select the penetration log for one hole at a timeFiltering of data to cancel bad data, rod exchange disturbance and/or collar disturbanceNormalize the penetration rate to % deviation from average valueCompensation for drilling depthCompensation for control changes in percussion pressure (feed pressure inclusive)Visualization of this value is called “normalized penetration rate” scaled in % and displayedin trends, 2D mapping and 3D as wishedBased on geology judgments the “normalized penetration rate” shall be calibrated to rockproperties and you can then assign scale and color mapping to describe rock hardness classes(type of rock). Legend can be defined by user. These calibrations must be done based oninitial logged MWD data as well as geologists description of rock hardness.Hardness visualization of “normalized penetration rate” in color maps scaled with rockhardness, 2D mapping and 3D as wanted.Fracturing estimation (homogeneity)Frequent variations on penetration rate and rotation pressure are the major response parameterto fracturing. High rotation pressure may also indicate fracturing of the rock but we estimatefrom the variations as calculated from the “root mean square” value. Our algorithm has thesesteps in our current implementation:Select the normalized penetration log/ rotation log for one hole at a timeCalculate “root mean square” of the normalized values aboveVisualization of this value is called “rms of penetration rate/rotation pressure” and will bedisplayed in trends, 2D mapping and 3D as wishedBased on geology judgments the “rms of penetration rate/rotation pressure” shall be calibratedto rock properties and you can then assign scale and color mapping to describe rock fracturingclasses (type of rock). Legend can be defined by user. These calibrations must be done basedon initial logged MWD data as well as geologists description of rock hardnessFracturing visualization of “rms normalized penetration rate /rotation pressure” in color mapsscaled with fracturing, 2D mapping and 3D as wanted.Water estimationWe have also implemented a water indicator that gives a warning on significant changes influshing water due to changed flushing resistance (compensated for water pump pressurevariations).8.4 Compensation for control changes in percussion pressure (feed pressureinclusive)The drilling energy is mainly put into the percussion process. Before the drill control systemswere very simple and did not change on the feed setting rotation or percussion during drilling.Then the penetration rate variations were direct influenced by the rock properties. In moderncontrol systems the systems itself behave very dynamic with functions like:Collaring settings at low percussion pressure and feed pressure.Jamming control initiates a ramping function of reduction/increasing percussion and feedpressure.Jamming control are triggered by high rotation pressure.Page 115