06 Aug Your Shale Testing Methods and Procedures for Fluid Selection are wrong
Dave Manning will be presenting on shale testing methods and procedures, co-authored with Dr Eric van Oort from EVO Energy Consulting (USA). It will be presented at the SPE Workshop: A Wake Up Call – Optimising Drilling Fluids, Waste Management, and Cementing to Address the Challenges of Increased Activities held on the 19th to 20th August in KL, Malaysia.
“Incompatibilities of fluids with clay-rich shale formations can lead to a plethora of serious operational problems, ranging from minor dispersion and accretion issues to major stuck pipe and production impairment events. The nature of fluid-shale interactions has confused scientists since the birth of the drilling fluid industry and has led to a variety of different test methods and protocols, many now decades old. Historical fluid-shale compatibility tests are often severely limited by over emphasizing the role of clay swelling behaviour, by not paying attention to shale sample condition (i.e using poor-quality, dried out core), and by not being specific regarding the intended purpose. Test selection is often based on a superficial assessment of the “reactivity” of the shale, and results are indiscriminately applied whether the intended purpose is e.g maintaining cuttings integrity, promoting borehole stability or avoiding reservoir incompatibility.
Various pitfalls and problems are associated with conventional tests, and the often disastrous consequences of following their erroneous guidance. New sets of rock mechanical tests methods and procedures, conducted with a clear purpose in mind on well-preserved or properly reconstituted shale material, are proposed that overcome the drawbacks of the conventional tests. To evaluate the borehole stabilization properties of fluid, for instance, it is best to forego traditional swelling tests and instead focus on triaxial failure testing, mud pressure transmission testing and bore-hole collapse testing. These new tests are presented together with references to field cases that followed their advice on fluid selection, and as a result experienced major improvements in operational performance.”