An apparatus for obtaining resistivity images of a borehole having an oil-based mud includes a rotating measure electrode on a measurement-while-drilling apparatus. The invention is characterized in that said pocket comprises a single peripheral seat common to several cartridges of different seat diameters, one or more portions of the outer rim of said peripheral seat 835 forming an indexing vertical wall common to said cartridges. The invention provides methods that have sufficient flexibility and scalability to be used for a wide variety of applications, including for producing industrial-scale quantities of extracts for the food and beverage industry. The ESP system is disposed within a tubing string located within the casing of a well. The predetermined bit pattern indicates that the associated portion of data was corrupted. The tabs are folded inwardly to at least partly overlie each other and are secured in position to form the floor of the housing by studs provided on the inflator which pass through co-aligned apertures in the floor-forming tabs.