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Unformatted text preview: formation. Brian Morel, BP Drilling Engineer, expressed this in an email to John Guide, BP wells team leader, on April 17, which stated: “I would prefer the extra pump time with the added risk of having issues with the nitrogen. What are your thoughts? There isn‘t a compressive strength development yet, so it’s hard to ensure we will get what we need until its [sic] done.” 93 3.
Nitrified Cement Another way in which BP sought to reduce additional lost returns during the cement job was by using a nitrified or “foamed” cement slurry in the annular space (the “tail cement” for the shoe track was unfoamed cement). Cement spets make nitrified or foamed cement by injecting cement with nitrogen bubbles while the cement is being prepared on the rig. Nitrified cement is less dense than unfoamed cement and therefore exerts less pressure on the formation. However, the use of foamed cement creates the risk of nitrogen breakout – if the nitrogen bubbles in the cement “break out” of suspension – which can result in inconsistent cement placement and densities. The use of nitrified cement in BP‐HZN‐CEC011406. BP‐HZN‐MBI0...
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