Do not rely on set standards!
Donald Leroy Purvis, a former employee of the largest US oil and gas companies, and now a retired independent consultant on well cementing issues addressed students and lecturers of Ukhta State Technical University, as well as professionals from the companies with such a recommendation. The guest lecturer arrived in Russia under the banner of the SPE «Distinguished Lecturers» program to deliver four lectures. The lecture themed; "Cement Tests: Are we properly looking at the ordinary things", took place on January 13th 2016 at the above mentioned university.
The most important aspect in wellbore construction is creating and maintaining wellbore integrity and zonal isolation. The potential of freshwater contamination has captured the attention of the public and media. A crossflow between productive intervals or saltwater zones can result in environmental and legal challenges, and lost production. The number of wells developing annular pressure over time has become a concern and expense for operators. The design and placement of a competent cement seal in the annulus is critical in addressing these issues. This presentation describes how the testing has progressed from Code 32, the first API code, to the present day ISO and API guidelines. The audience should gain a better understanding of what cement is needed to do and the laboratory tests required to make sure it does.
Donald L. Purvis drew the audience's attention to such an important issue for the industrial production of hydrocarbons; well cementing. Precisely, he emphasized on the reliability and objectivity of modern testing problems concerning cement mixture before its use in the production industry.
Despite the fact that since the 1930s when American engineers for the first time drew attention to the composition and properties of industrial cements, their formulation has been continuously improved and testing is becoming more complex. In spite of this, about one-quarter of cementing work passes unsuccessfully as cements do not constrain the inflow of hydrocarbons into the well with one hundred percent reliability. Although the effects of this according to Donald Purvis aren’t catastrophic, the cause of almost half of today’s hydrocarbon spills from wells in the Gulf of Mexico remains shortcomings during well cementing.
To solve this problem according to the lecturer, the US and global oil and gas industry need to recognize the fact that current cement testing standard do not take into account a very important point - in the laboratory cement behaves quite differently than in the well where it is subjected to a plurality of unrecorded impacts. That is why it is not necessary for future oil and gas industry engineers to unconditionally trust accepted testing standards. The lecture concluded with the lecturer taking questions from the attendees.