Lines with other classes and within this classA. RELATIONSHIP TO CLASS 175, BORING OR PENETRATING THE EARTH The relationship of Class 166 with boring or penetrating the earth, classified in Class 175, is close both for historical and functional reasons. The lines between Class 166 and Class 175 are set forth in the class definition of the latter class with the exception of the below noted reference to cementing. While Class 166 is generic to processes including earth boring or penetrating steps no general subclass has been provided in Class 166 for combinations with earth boring since earth boring of some kind is always associated with well making and the relationships expressed in the claims of patents were thought to be better classified on other bases in this class, see Class 175 subclasses 57+ and the search there noted for earth boring processes, per se. Generally in relation to apparatus Class 175 is more comprehensive than Class 166 and takes combinations of Class 175 and Class 166 subject matter. Class 166 however, takes some miscellaneous subcombinations which may be disclosed as used only in drilling operations but which are in fact of general utility in wells, particularly when there is no suitable subclass provided in Class 175 and a suitable subclass is provided in Class 166. Processes of cementing, plugging or consolidating as defined in Class 166 subclass 21 are distinguished from drilling with fluid processes classifiable in Class 175 subclasses 65+ by the interruption of the actual earth cutting operation of the drilling process. Thus a process which purports to be a drilling process but which includes in its disclosure some indication that the actual earth cutting has stopped to permit cementing, such as a statement that "drilling is resumed" or that "after the cement has set", will be considered a cementing process for Class 166. The fact that a drilling tool stem or shaft is disclosed as the means for delivering the cementing materials below ground or a disclosure that drilling mud or drilling fluid is used as a carrier for or a constituent of the cementing material will not preclude classification in Class 166. Such processes in which drilling is interrupted to permit cementing are classifiable in Class 166 even if the cementing step is only normally or inferentially claimed. See, however (1) Note in Class 166, subclass 21. B. RELATIONSHIP TO PUMPS The general line between Class 417, Pumps and Class 166 is that if subject matter relating to a feature peculiar to a well is claimed in combination with Class 417 subject matter, classification is in Class 166. The following categories of subject matter more specifically delineate this line. 1. Class 166 Subject Matter Classifiable With Class 417 Subject Matter in Class 417. a. Combinations of certain subcombinations, which if claimed, per se, are classifiable in Class 166, those with Class 417 subject matter are classifiable in Class 417. A recitation of a well broadly, or with certain well features will not exclude a patent from Class 417. The following are examples of such features which would be classifiable in Class 417: i. a well tubing or conduit. ii. structure in well tube to support a Class 417 device. iii. a packer or anchor for sealing a Class 417 device in tube. iv. a below ground check valve in pump inlet or outlet. v. a valve which drains Class 417 device. b. In examples iv. and v. it should be noted that a broadly recited pump or pump barrel with an anchor, packer or drain valve is classifiable in Class 166 in appropriate anchor, packer or valve subclasses. 2. Class 417 Device Combined With Below Ground Separator or Screen. A well screen, as defined in Class 166, subclass 227, generally contacts the earth wall of the well bore as a continuation of a casing. A solids separator or inlet screen for a pump tube in a well is generally disposed inside the casing and well screen. A well type screen specifically described as such and claimed in combination with a pump as more than an opening or a passage for fluid is classifiable in Class 166. A gas separator or anchor disclosed as in a well, even though claimed in combination with a Class 417 device is classifiable in Class 166 (see Subclass References to Current Class, below), except as noted in section D below. Further, a sediment trap or deflector (e.g., sand trap) disclosed as in a well is also classified in Class 166 (see Subclass References to Current Class, below) even though claimed in combination with a pump. 3. Above Ground Well Structure Combined With Class 417 Device. Generally the combination of a Class 417 device, whether above or below ground, with above ground well apparatus for handling pumped fluid or supporting a pump driving means is classifiable in Class 417. Note, however, that features which relate the well structure to the earth, such as placing pipes below the frost line or embedded foundation which also supports well casing will cause classification in Class 166. 4. Below Ground Fluid Entrainment Type Pumps and Flowing Wells. a. Class 417 will take an aerating column, jet, gas lift or other entrainment type pump, per se. See References to Other Classes, below. b. Class 166 will take Class 417 device as set forth in paragraph (1) when the solely disclosed and claimed means for supplying all the motive fluid to the device is located in the well and collects the motive fluid by trapping or separating well fluid in the well (e.g., gas anchor, packer with gas passage to central conduit etc.). c. Class 417 will take subject matter similar to that in paragraph (2) above when there is a specific description of means to supply additional motive fluid from the earth surface or a point outside the well. This classification prevails even though the additional motive fluid may have been originally obtained from the same well. Obviously combinations of these features with other well features may cause classification in Class 166. 5. Summary of Well Feature. a. The following features, claimed in combination with a Class 417 device, are representative of the type of subject matter in general which will cause classification in Class 166: i. Any specific relationship of the Class 417 device or other fluid conducting structure to the earth or earth formations as: plural pumps in plural wells; single pump connected to a plurality of wells; inlets from a plurality of earth formations; location of parts in relation to the frost line in earth; lateral conduit below ground; earth contacting well screen; and earth embedded support for tubing or casing. ii. Any specific relationship to well operation or structure, such as: process steps in addition to installation, removal or operation of a pump; control of pump or pumped fluid in response to a condition sensed in a well; control or pump or pumped fluid in relation to operation of another device in the well, other than mere flow check valves; above ground separation of fluids leaving well for purposes other than the production or removal of pump operating or motive fluid; apparatus, not forming a part of the pump itself, for handling or manipulating pump parts; passages for pumped fluid specifically described as directing the fluid to wash, clean or otherwise treat the well; sediment traps or deflectors; and gas separators (but see Section 4c above). C. WELL SHAFTS AND METHODS AND THE LIKE ELSEWHERE CLASSIFIED Well shafts or shafts sunk in the earth and structurally similar to well shafts, and methods of operating wells are not all classified in Class 166. See References to Other Classes for classes that provide for shaft structures and methods which are equivalent or very similar to those found in Class 166. D. DEVICES OR PROCESSES IN WELLS OR THE LIKE ELSEWHERE CLASSIFIED Class 166 provides for various well treating and flow controlling devices to be inserted into a well below the ground level, but other classes also provide for similar devices. In cases of doubtful classification the fact that a device is disclosed only for use below ground in a well should incline classification towards Class 166. Class 166 provides for example, for apparatus and methods for fluid sampling in a well for cementing, washing, or mechanically cleaning a well, acidizing or otherwise treating a formation, packing, plugging, heating, cooling, dissolving paraffin, separating materials in a well, (including liquids from liquids, gases from liquids and solids from liquids), graveling or otherwise forming strainers in a well, and anchoring devices in a well. See References to Other Classes, below, for other classes which take devices inserted in a well or analogous devices and processes relating to such devices. E. REFERENCES INTEGRAL TO AND EXTERNAL TO THIS CLASS Subclass References to the Current Class, below, includes both subclass references integral to Class 166 as well as references to art areas external to this class. | 
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