Abstract: Methods and apparatus to measure physical parameters such as density and porosity of the rock matrix in a near wellbore area are provided. A borehole tool having a number of transducer elements in a transducer array is placed at an outermost surface of the borehole tool and is capable of emitting focused high frequency ultrasound beams into the rock matrix in the near wellbore area. The transducer array may be placed on the ribs or stabilizers of the borehole tool, and/or on a sleeve with a lower rotational speed, and may include a fronting material with similar acoustic impedance as the rock matrix. A method for measuring physical parameters of the rock matrix in a near wellbore area is also provided where a focused high frequency ultrasound beam is emitted into the rock matrix in the near wellbore area from one or more transducer arrays on a borehole tool.