Abstract

Oil and gas exploration and development projects require reservoir properties that must be evaluated to help ensure both economical and operational success. These reservoir properties include determination of volume of original hydrocarbon in place, the residual hydrocarbon saturation after sustained production, and the reservoir drive mechanisms. Additionally, an accurate analysis of the hydrocarbon properties is essential to optimize reservoir depletion and production forecasting. Collecting core samples from the reservoir is one method to obtain important reservoir properties; however, limitations and uncertainty may result from the methodology routinely applied for reservoir core sample recovery. The significant loss of reservoir fluids through the use of traditional core recovery and retrieval processes was documented more than 75 years prior and has continued to present an ongoing economic and operational challenge to our industry engaged in hydrocarbon exploration and development.

A discussion of a new wireline sidewall coring technology designed to retain both reservoir rock and associated entrained fluids within a sealed pressure vessel that eliminates the loss of important reservoir fluids during the core recovery process. Capturing formation fluids, rather than estimation of lost fluids volumes, has shown to improve analysis of reservoir hydrocarbon volumes when compared to traditional coring systems. The composition and saturations of formation fluids within the reservoir are also important parameters for reservoir management and production forecasting. Additionally, collecting formation fluids allows for analysis of the fluid properties, which are critical to the design of completion and production strategy for hydrocarbon reservoirs. Field and laboratory operational procedures for this wireline core technology is presented.