Abstract Drilling and cementing operations in Malaysia's oil and gas wells are frequently challenged by severe to total lost circulation due to the fractured and fissured nature of unconsolidated formations. These issues often lead to increased operational costs and compromised well integrity. Lost circulation during cementing is a critical concern, as it directly impacts zonal isolation and can result in various detrimental consequences including reduced process safety, tubing corrosion, sustained casing pressure, formation damage, loss of production rate, and costly remedial operations. Such losses are typically experienced in vugular or cavernous formations and high permeability zones, with the most frequent occurrences in depleted, highly fractured (induced or natural), or loosely consolidated sandstone and claystone, zones which can be breached at relatively low hydrostatic pressures. This paper presents a successful application of an innovative approach to control lost circulation by utilizing a dual deployment of a fiber-based lost circulation pill alongside an engineered thixotropic cement slurry. This novel method of using integrated technologies has demonstrated exceptional effectiveness in mitigating lost circulation in large fractures up to 10-mm width, even in scenarios of severe to total losses. The strategic implementation of this solution has yielded significant reductions in rig time, decreased mud loss during drilling, and enhanced zonal isolation and wellbore integrity during cementing operations. The findings highlight the potential of this approach to optimize drilling and cementing processes, thereby improving operational efficiency and safeguarding well integrity in challenging formations.
Thanasarnpisut et al. (Mon,) studied this question.