1) In the where clause you have:
WHERE Tdril.techid = SELECT Tech
this is wrong for 2 reasons: a) you cannot use the sql keyword "SELECT" in the where clause and b) The actual name of the parameter is "SelectTech"
the where clause should be:
WHERE Tdril.techid = SelectTech
2) for the runtime value of the SelectTech parameter, you entered:
this is not a valid php variable. the run time value should be: