Abstract: In the last ten years, a new type of modern polymer, known as swelling elastomer, has been used exten- sively as a sealing element in the oil and gas industry. These elastomers have been instrumental in various new appli- cations such as water shut off, zonal isolation, and sidetracking. Though swell packers can significantly reduce costs and increase productivity, their failure can lead to serious losses. The integrity and reliability of swelling elastomer seals under different field conditions is a major concern. The investigation of changes in material behavior over a specified swelling period is a necessary first step for performance evaluation of elastomer seals. The current study is based on experimental analysis of changes in geometric and mechanical behavior (hardness, tensile, compressive, bulk) of an elastomeric material due to swelling. Tests were carried out before and after various stages of swelling. Specimens were placed in saline water (0.6% and 12% concentrations) at a temperature of 50°C, with the total swelling period being one month. Swelling, hardness, compression, and bulk tests were conducted using disc sam- ples, while ring samples were used for tensile experiments. A small test rig was designed and constructed for deter- mination of bulk modulus. Stress-strain curves under tension and compression, and pressure volumetric-strain curves were obtained for specimens subjected to different swelling periods. Due to the fast-swell nature of the elastomer, there were sharp changes in mechanical properties within the first few days of swelling for both salinities. Elastic modulus derived from tensile and compressive tests showed a 90% decrease in the first few days. Bulk modulus showed fluctuation in its variation with an increasing swelling period. There was a small effect of salinity only dur- ing the first 5 or 6 days. Keywords: Swelling elastomer, Swelling behavior, Tensile testing, Compression testing, Bulk testing

Abstract: In the last ten years, a new type of modern polymer, known as swelling elastomer, has been used exten- sively as a sealing element in the oil and gas industry. These elastomers have been instrumental in various new appli- cations such as water shut off, zonal isolation, and sidetracking....