Production fluids and the fluids inherent in well site operations are often complex mixtures containing oil, water, natural gas, sand, rust scale and low density debris. There are oil, water and gas separators well known to those skilled in the art of petroleum production that are efficient in separating the usual production at high rates but will not produce water clean enough to be environmentally acceptable. Sand and low density debris can be removed at high rates by well known techniques. Effluent water from the high rate separators often requires further processing and the water to oil ratio is often rather high.
Very small bodies, or particles, of oil dispersed in water will usually float upward but the rate may be so slow that unacceptably large holding tanks would be required to use that approach. Additionally, small particles of oil may adhere to heavier random particles and fail to rise at all in water.
Water containing dispersed oil can be tumbled or rolled to cause oil particles to coalesce into larger particles that will rise faster. If the agitation is too violent, the opposite effect will be realized. The amount of agitation needed to cause coalescence of oil particles maY not be conducive to selective migration of the coalesced particles while in the region agitated. It follows, then, that there is advantage in agitation iollowed by relative quiescence in the general migration of the fluid body being processed. Further, repeated sequences of agitation and quiescence continues to improve the quality of water destined to become efiluent.
Quiescence has a singular quality requiring little attention but agitation has qualities that do influence results. The ideal agitation has little value if it exists in only selected regions of the stream progressing through an enclosure. An ideal agitation, to be most effective, will subject all the fluid stream to the same effect. Baffles in the structure directing the stream being processed have been found quite effective but they are often of such shape that they agitate one part of the stream more than another. Baffles may still do what is required but more baffles may be required and needed dimensions are not always available.
Fluids to be separated at different sites, and fluids from the same site at different times, may vary enough to require fine tuning of the fluid handling process. Fine tuning to optimize a baffle system can be more readily accomplished if the agitation region is reasonably homogeneous. Adjustment of the flow rate through the baffle system is the usual fine tuning procedure. If the agitation of the stream is not homogeneous, flow rate adjustment merely shifts the ideal agitation level to a different part of the stream, with too little agitation in one region and too much in another.
Each baffle commonly receives some separated oil in the quiescent region. It is rather important that the oil be removed from each quiescent region without further agitation until the oil is confined for removal to a collection region.
It is therefore an object of this invention to provide a baffle type fluid separator with fluid processed through the agitation region such that the stream is agitated with reasonable uniformity.
It is a further object of this invention to provide a baffle type fluid separator with quiescent regions for light element collection having means to withdraw collected fluids without further agitation until extracted from the quiescent region.
It is yet another object of this invention to provide an oil collector riser tube full length of the baffle structure to reduce extraction velocity to allow water particles in the oil to separate after oil extraction is underway.
It is still another object of this invention to provide an oil collection box slip jointed to the oil collection riser to simplify installation without welding at the well site.
These and other objects, advantages, and features of this invention will be apparent to those skilled in the art from a consideration of this specification, including the attached claims and appended drawings.