Sucker Rod Guide

Types of Rod Guide

Three designs are in common use. The fluted guide is a molded polymer sleeve with longitudinal fins that centralize the rod, so the fins contact the tubing rather than the rod or the coupling, and they are simple, cheap and widely used in moderately deviated wells. The wheeled guide has metal or polymer wheels set in a cage, so the guide rolls along the tubing wall rather than sliding, giving much lower friction and longer life, and it is the standard choice in horizontal and highly deviated wells where sliding wear would be severe. The snap-on guide is a split design that can be fitted to the rod body without removing the coupling, which makes it quick to install in the field, and it is used where the guide must be added or replaced during servicing. The choice depends on the dogleg severity, the well inclination and the expected side load.

Material Selection

Rod guide material is selected for wear resistance, friction and compatibility with the well fluid. Nylon is the most common general purpose material, with good wear resistance and moderate cost. Ultra high molecular weight polyethylene, UHMWPE, has lower friction and better resistance to abrasion and to impact, and is used in deviated wells and where the produced fluid is heavier. Polyurethane gives high wear resistance and is used in abrasive conditions. Where the well is sour, the guide material must be resistant to H2S and to the produced fluids, because a degraded guide can come loose, fall into the pump and cause a costly failure. Where the well is hot, the temperature limit of the polymer matters, since a guide that softens at downhole temperature will deform and lose its centralizing function. Confirm the fluid composition and the downhole temperature before selecting the material.