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tus. API standards for testing proppant conductivity 2,3 make no reference to the distribution of proppant, correction for connection to the wellbore, degree of effective reservoir exposure, etc. Fracture conductivity is the total of all components that affect the delivery of reservoir fluids to the wellbore, including (1) proppant conductivity, (2) propped fracture communication with the wellbore, and (3) aftereffects on conductivity in the propped fracture with respect to production or time. Because many contributing factors cannot be established before a treatment, no prejob method of quantitatively testing fracture conductivity exists. Fracture conductivity must be determined after the job is completed.One could assume that proppant conductivity is a product of proppant and gel damage. Fracture conductivity, then, would be the placement of proppant conductivity. Based on this perspective, much research about proppant conductivity actually applies to fracture conductivity, and the information that the production engineer needs is fracture conductivity contrast. Establishing and maintaining contrast are key to proppant-pack production. The production engineer needs a means to deliver reservoir fluids to the wellbore fulltime. The ideal mechanism would be a highly conductive pipeline that is resilient to contamination and stress changes, is properly connected to the tubulars, and never needs cleaning. This paper contains authors comments about proppant and fracture conductivity and the factors that change them with time. Laboratory examples and case studies that support data from these studies are presented. Effects of stimulation, fracture load recovery, production, and stress cycling on fracture conductivity are discussed. Case histories that relate to laboratory observations and theory are also included. Obtaining Conductivity Through Better ChemistryProppant-pack conductivity measurements provide a performance property for the formation that will be fracture-stimulated, and may not truly represent the effective fracture conductivity or performance of a fracture. However, they can help identify the major detrimental effects on conductivity and ways to reduce these effects.Breakers. The residue in gelled fracturing-fluid systems reduces proppant pack conductivity. 4 This residue may be bulk gel AbstractThe emergence of accepted proppant conductivity testing methods has led to much discussion about what is needed to regain high conductivity levels, and several marketing campaigns have been based on these findings. The industry has generally accepted the principle that delivering high conductivity levels in the fracture is key to achieving high production levels. This paper does not refute this point, but modifies it.This paper presents theory, laboratory data, and case histories indicating that high initial conductivity levels can only gain high initial levels of potential or actual production. For sustained, high production levels, the proppant packs integrity must be maintained. With time, most proppant packs...