Subterranean zones that contain valuable deposits frequently include other materials, such as entrained water or solids, that are considered extraneous. Since such materials can interfere with the production of the valuable deposits, it may be desirable or necessary to have some way to remove extraneous materials from the production well bore. One method for handling extraneous, co-produced materials is to form a “sump” or “rat hole.” The sump is a well bore drilled below the production well bore such that extraneous materials are allowed to fall into the sump and to collect therein. Sumps may be drilled vertically or obliquely from an existing well bore.
As materials are collected within the sump, the sump may become nearly or completely filled. In such instances, it is desirable to remove some of the collected material in order to provide sufficient capacity for new material to be collected in the sump. For example, a pump may be lowered into the sump, and water may be pumped to the surface. Such techniques permit the sump to be used to facilitate production after the capacity of the sump would ordinarily have been exhausted. Therefore, it is advantageous to have efficient and versatile methods for removing collected material from a sump. Furthermore, collected materials with a high solid content may present additional challenges for the removal process. For example, the solid phase material may obstruct the flow of collected material through pumps and potentially damage pump mechanisms. In another example, the relatively low liquid content of such collected materials may prove insufficient liquid flow to adequately lubricate and/or cool various types of pumping mechanisms. Consequently, it would be useful to have a technique for extracting collected material that can effectively remove materials with a high solid content as well.