1) Draw near 2) Encircle 3) Encircle and isolate 4) Narrow the gap 5) Pen up 6) Prepare for capture 7) Prepare to raid 8) Tighten the circle 
1. o shut in a well temporarily that is capable of producing oil or gas. 2. to dose the blowout preventers on a well to control a kick. The blowout preventers close off the annulus so that pressure from below cannot flow to the surface. 
[v] - advance or converge on
verb advance or converge on; `The police were closing in on him`
near, as to a common center; adjacent, esp. to a city: The city is enveloping its close-in suburbs. · occurring or provided at close quarters: Fighter planes provided daring close-in air support.