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New completion techniques using expandable casing with swelling elastomers to seal the annulus, or just swelling elastomers used as packers are becoming available. Diagnostic services are required for these new completions such as evaluation of the annular seal, analogous to cement evaluation. Both conventional and new generation Wireline ultrasonic measurements have been used to characterize and possibly evaluate zonal isolation using swellable elastomers. So far, the following 360 degs circumferential measurements were studied: Ultrasonic radii, acoustic impedance (AI), as well as attenuation and third interface Echo (TIE) reflections from flexural wave data. Radii measurements show a "springback" effect, indicating that expansion against the formation has been achieved. Flexural attenuation has a much better dynamic range over the elastomer sections compared to the acoustic impedance measurements. Both measurements do not consistently distinguish rubber-backed casing with ordinary casing in our examples. The TIE from the latest generation imaging tool tracking the external rubber interface, may provide the measurement the industry needs. First results look promising and further experiments to characterize the tool response are ongoing. The casing geometry of expanded liners was also studied. Introduction The introduction of expandable metal technology and new "smart" materials like swelling elastomers will provide more options for well construction and completion:New techniques in zonal isolation are now possible for over - underpressured, fractured zones and zones with fluid losses [1], [2],Allowing monobore well design [3],Production of selected zones will be made easier, like selective perforation, completion, and stimulation [4],Multilateral junction sealing will be made easier. The effectiveness of zonal isolation and long-term well integrity for this new technology needs to be evaluated and proven. " Smart Material" - Swelling Elastomers Swelling elastomers are now offered by several service companies and have been used by operators for a variety of applications: As a means to establish zonal isolation in liner completions where conventionally a cement column would be used [5], as a production separation packer (swelling packers are used to replace conventional hydraulically or mechanically set packers) [6], and as an integral part of an expandable open hole clad [1]. By incorporating filler materials into an elastomeric matrix the material reacts or swells with time if in contact with water, depending on the elastomer and the requirements [7]. A water swellable elastomer swells through the absorption of (saline) water (osmosis process). An oil swellable elastomer swells primarily through the absorption of hydrocarbons (diffusion process). The typical swelling ratio is about 1.75 to 2.5 and swelling pressures are up to 150 bar. Swelling time is from 5–100 days depending on produced water salinity, temperature and oil viscosity and composition. The longevity of swelling elastomers still has to be quantified.

Current acoustic (sonic and ultrasonic) techniques for cement evaluation have proved to be limited in providing unambiguous answers to the zonal isolation issue. This is especially true in lightweight cements where they often fail to differentiate cement from mud. Also, as far as imaging of the cement sheath is concerned, ultrasonic pulse-echo tools fail to image beyond the cemented region adjacent to the casing, thus providing limited diagnosis of the annulus. A new ultrasonic imaging tool has been developed to address these limitations. The new imager combines the classical pulse-echo technique with a new ultrasonic technique that provides temporally compact echoes arising from propagation along the casing and also reflections at the cement-formation interface. Processing these signals yields unprecedented characterization of the cased hole environment in terms of the nature and acoustic velocity of the material filling the annulus between casing and formation, the material immediately behind casing, the position of the casing within the hole, and the geometrical shape of the hole. Different wells cemented with conventional and light cements were logged with the new experimental tool. The results demonstrate enhanced cement evaluation for both cement types and significant reduction in the uncertainty in making a squeeze or no-squeeze decision. Introduction Cement evaluation logging tools have been used successfully for many years to evaluate casing and cement conditions. These tools, which use sonic or ultrasonic1 techniques, are designed for conventional steel casing and cements. The sonic tools, commonly known as Cement Bond Log or CBL, operate at frequencies of about 20 kHz and measure the amplitude or the attenuation of a wave traveling along the casing. The wave loses energy mainly though shear coupling to the surrounding cement, so that well-bonded solid cement attenuates more quickly than a fluid. Due to the low frequency, the CBL logs made with these tools lack azimuthal resolution, which makes it difficult to distinguish channeling from poor cement properties.

AUGUST 1982 casing deformation and have identified casing corrosion and wear.