Tex. Tax Code § 191.081: DEFINITION.

In this subchapter, "oil well service" means cementing the casing seat of an oil or gas well, shooting, fracturing, or acidizing the sands or other formations of the earth in an oil or gas well, or surveying or testing the sands or other formations or their contents in an oil or gas well by using instruments or equipment at least a part of which are located in the well bore when the survey or test is made.

Acts 1981, 67th Leg., p. 1723, ch. 389, Sec. 1, eff. Jan. 1, 1982.