Study On Disposal And Long-distance Conveying Of Drill Cuttings On Drilling Platform

Drill cuttings belongs to the solid waste pollution, which is the useless solid phase of the waste drilling fluid after solid-liquid separation. Drilling cuttings are harmful solid waste product during drilling operation, for there're a lot of organic matters and toxic heavy metal ions in them. The discharge of drilling cuttings created serious marine environmental pollutions, so they must be harmlessly treated. Unlike the land-based drill operation, the offshore drilling's drill place is limited to the drilling platform, and there aren't large enough places to handle the drill cuttings in sewage pool. So people always discharged the drill cuttings and drill waste into the ocean directly. As the awareness of people's environmental protection growing, in order to meet the requirements of environmental protection laws and regulations, oil companies transport the drill cuttings by boat, but this method cost much and was limited by the weather. In order to reduce the cost of offshore drilling waste transportation, many foreign oil companies start to do some researches of the new technologies about local processing of drilling waste.This paper studied on the treatment of drilling cuttings during the offshore drilling. According to the demand of the four-hundred transportation distance and the area limitation of the drilling platform, proposed a solution that treated the drilling cuttings on the platform firstly, and then transported the cuttings to land for further treatment. The main contents are as follows:Firstly, two different programs was put forward based on the level of solid-liquid separation of drilling waste, which were paste cuttings transport and granular cuttings transport. Then, analyzed the structural and transportation features of the two different conveying systems, one was the negative pressure pneumatic conveying system, the other was the positive pressure pneumatic conveying system. At last, decided the continuous positive pressure pneumatic conveying as the research program according the work requirements.Secondly, the system principle and work flow of positive pressure pneumatic conveying system was analyzed, and the problems existing in the pneumatic conveying process was studied on. This paper optimized the feeder and replaced the ball valve by the latest dome valve, which is a good solution to the valve wear.Thirdly, the important parameters in the pneumatic conveying system was calculated according to the requirements of transportation, such as the conveying distance and the conveying capacity, then select the air compressor and the dryer.Lastly, the conveying system simulated with the fluid simulation software, and the simulation results showed that this simulation model had high accuracy and good predictive ability.