Validation of Geomechanical Sanding Evaluation, Examples from Australian Gas Fields

Abstract Geomechanical sanding evaluation has become a key tool in the development of fit-for-purpose sand management strategies. Geomechanical analyses identify the likely sand producing intervals, the timing and the severity of sanding. Sanding predictions are ideally calibrated against field sanding observations or rock mechanical simulations of laboratory tests on representative rock samples. However, in the absence of field observations, the validity of geomechanical predictions can be a concern for field development planning, well design or well intervention decisions. In this paper the validity of sanding evaluation conducted at early field life for sand control and completion decisions are examined with the help of historical production data in two different Australian gas fields with different geological settings, tectonic stress regimes, rock strengths, well types and operation conditions. The field cases include: 1) the Geographe gas Field in Otway Basin offshore south east Australia with nearly 2.5 km long horizontal wells open hole completion with pre-drilled liner and more than 13 years of production with depletion reaching 80%, and 2) the Waitsia gas Field in Perth Basin in Western Australia with vertical and low angled cased and perforated wells on production since 2016. The case studies demonstrate the validity of geomechanical assessments conducted at early field life that are verified with several years of production later, with different outcomes and observations. It is shown that with robust geomechanical sanding modelling and frequent updates, reliable sanding risk assessments can be provided to well engineers and asset managers for sand management and completion decisions.