The parachutist experience the amount of acceleration. While he was just opening first the parachute, the acceleration is high. When he was falling with an already open parachute, the amount of acceleration decreased. he was falling slower. Ofcourse, he experienced the amount of acceleration.
The parachutist is falling down with an open parachute - this means that the air resistance increases. As the air resistance increases, the acceleration reduces gradually until it becomes zero. Therefore, he experiences acceleration but with decreasing acceleration.
Gravity is regarded as a constant causing acceleration of 9.81 m/s per second on Earth and will affect a skydiver jumping from any altitude. A terminal (maximum) velocity is reached after about 15 - 20 seconds when the air-resistance of the diver balances out the effects of gravity. For a skydiver in a free-fall position with a semi-closed parachute, this is about 120 mph (195 km/h or 55 m/s), but if the diver pulls in his limbs, this increases to about 200 mph (320 km/h or 90 m/s) and in the he