An Acoustically Controlled Down-Hole Safety Valve (SCSSSV)

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. Abstract A surface-controlled subsurface safety valve (SCSSSV) system without external wires or hydraulic lines needed for the valve's operation is now available to the petroleum industry. Any of the current down-hole safety valves, such as Hydril, Otis, Camco or Baker, can be fitted to the valve operator. This is a totally fail-safe valve system, which can be overridden manually at the operator's choice to accomplish a number of different modes. The valve's operator is acoustically controlled by the operator's predetermined settings at the surface. The predetermined settings at the surface. The receiver, translator, and valve actuator are packaged and placed in a special mandrel that is packaged and placed in a special mandrel that is run as a part of the tubing string. The hydraulic valve operator is mounted on a length of production tubing between the mandrel and valve. The full-flow valve is at the bottom of the down-hole string. Any length of production tubing may be run below the valve. Hookwall hangers can be run in as may be needed. The down-hole electronics is a module set in a side-pocket mandrel with wireline equipment. Setting depth can be below "paraffin" zones. The system does not reduce production flow and will permit other wireline operators to pass to other equipment below the setting depth. REVIEW OF THE STATE OF THE ART With the movement of the oil industry into the more or less hostile environment of offshore operations, it was apparent immediately to the oil operators that an automatic "fail-safe" valve was needed for the producing oil or gas "flow string". A valve was produced that would respond to changes in flow rate either above or below levels preset into the valve. The first valve to be so adapted and so employed was the differential pressure, spring-loaded valve. Abnormal increases in the flow rate across the valve caused it to close. This valve was very simple in construction, could be set in the production string and removed by means of a production string and removed by means of a wireline. The differential pressure valve and its "sister" valve, the ambient pressure valve, which closed automatically if the rate of flow or resultant pressure across the valve dropped below a preset valve. These safety valves became known to the oil industry as "storm chokes", but actually the term "storm choke" is a registered patent term; therefore, such valves should only be referred to as down-hole production string safety valves. production string safety valves.