Try the following array formula:
Code:
=INDEX(Well!C:C,MATCH(MIN(ACOS(SIN(RADIANS(B7))*SIN(RADIANS(Well!A$2:Well!A$151))+COS(RADIANS(B7))*COS(RADIANS(Well!A$2:Well!A$151))*COS(RADIANS(C7-Well!B$2:Well!B$151)))),ACOS(SIN(RADIANS(B7))*SIN(RADIANS(Well!A$2:Well!A$151))+COS(RADIANS(B7))*COS(RADIANS(Well!A$2:Well!A$151))*COS(RADIANS(C7-Well!B$2:Well!B$151))),0)+1,0)
The approximate minimum great circle distance (in km) is given by the array formula:
Code:
=MIN(ACOS(SIN(RADIANS(B7))*SIN(RADIANS(Well!A$2:Well!A$151))+COS(RADIANS(B7))*COS(RADIANS(Well!A$2:Well!A$151))*COS(RADIANS(C7-Well!B$2:Well!B$151))))*6367.465
For distances in miles, replace the 6367.465 with 3956.559.