Not less than fifteen nor more than thirty-five days before the first day of each week of any regular or special term of the circuit court the jury commissioners shall proceed to draw at least seventy-five petit jurors to serve for that week only. The chief administrative judge or the presiding judge of that circuit may increase or decrease the number of jurors drawn if he considers it necessary; however, at least seventy-five jurors must be drawn. The jury commissioners shall randomly select the jurors and shall not excuse or disqualify any juror who has been selected. Immediately after the petit jurors are drawn, the clerk of the court of common pleas shall issue his writ of venire facias for the petit jurors, requiring their attendance on the first day of the week for which they have been drawn and this writ of venire facias must be immediately delivered to the sheriff of the county.