According to the pilot, while at 5,000 feet in cruise flight, the low oil pressure enunciator light illuminated. The pilot reported the low oil pressure condition to Augusta Approach, and they vectored him towards the Burke City Airport. The pilot reduced power and started his descent. The pilot stated that the engine began surging then "quit/seized followed by smoke billowing out from the engine cowling." The pilot declared an emergency to Augusta Approach and decided to make an off airport landing. During the approach to landing the pilot realized that the field he chose to land on had just been harvested of trees leaving several tree stumps protruding above the ground which the airplane struck. The landing gear collapsed after touch down and the airplane skidded to a stop. The pilot stated that he was not injured, and was also unable to contact Augusta Approach either by radio or cell phone. The pilot stated that he walked about 1/4 mile until he could get a signal on his cell phone to report the accident. According to the airplane owner/operator, a mechanic had installed an engine oil quick drain prior to the flight. The mechanic was unaware that a quick drain was not recommended for installation on the PA-28R, as a result when the pilot retracted the landing gear after takeoff, the nose gear compressed the quick drain allowing the engine oil to drain out during the pilot's flight. According to the operator, after the accident the president of the company directed that all shop employees be given instruction in regards to why quick drains should not be installed on PA-28R Piper Arrows. Examination of the airplane by an FAA inspector found that the airplane sustained substantial damage to both wings and the fuselage.