This paper presents our research on developing new lightweight and ultra-lightweight cement formulations which have resulted in higher cement strength, better adhesion and improved cement bond logs. The resulting formulation could be used for deeper placement in wells. Traditionally, these have been viewed as technology limiters for lightweight cements.

We screened local raw materials, cement available in Saudi Arabia. This in combination with carefully selected glass microspheres, have resulted in unique ultra-lightweight cement formulation. Careful selection of particle sizing and micro-additives has resulted in better adhesion. This paper describes the formulation, lab test results, and structural properties found through use of x-ray diffraction analytical testing. Additionally, it shows a comparison among the various density formulations with different microspheres and additives. Success in formulating with locally available ingredients improves supply chain flexibility – often a key in successful operations.

Our results show nearly double the mechanical strength expected from a lightweight formulation lower than water density. Systematic approach considered during fluid optimization. The Paper will highlight the improved crush resistance of the beads and summarize the robust laboratory tests performed to qualify it for applications in a wide variety of challenging down-hole conditions including lost circulations and weak formations. Due to more predictable downhole density, complete circulation can be achieved deploying this slurry. The set cement mechanical properties, including compressive strength, have significantly improved which is essential for ensuring long-term isolation. Conventional water-extended cement slurries are not considered adequate to isolate unconventional reservoirs such as shale and tight sandstone.

We believe this formulation discovery, when further optimized, could be the basis of high-performance lightweight cement systems that are capable of deeper placement in the wells with improved pumpability and on-location rheology and set time control. Our formulations leverage normally available particulate materials to the best of our knowledge.

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