Abstract

Wells are typically drilled for exploration and production of oil, gas, water or geothermal energy from the underground.

Well cements are needed for providing an effective zonal isolation (hydraulic seal) and anchoring of steel pipes (casings) in such wells. The cement sheath between the formation wall and the casing string shall ensure proper flow of production fluids into the well. Leaky cement sheaths may lead to loss of production fluids from the payzone into other formations or even to dangerous blowouts to the surface. Defectively conducted cementing jobs are not easy to repair and in many cases not at all. Providing an effective sealing is made more difficult by extreme temperature and pressure conditions especially in wells for production of oil and gas from deep formations or in geothermal wells (up to 350°C).

This course explains the production and properties of oil well cements. Dyckerhoff well cements are produced and tested in strict accordance with the standards API Specification 10A, "Specification for Cements and Materials for Well Cementing" and ISO 10426-1 "Petroleum and natural gas industries - Cements and materials for well cementing - Part 1: Specification".

Each order for Dyckerhoff API Well Cements is subjected to a conformity test in accordance with the above mentioned standards as well as to specific performance tests agreed with the customers.

It is explained how these test are performed in order to fulfil the requirements of the cement plant’s quality management system.