Lost circulation is a recurring and costly challenge for the oil and gas industry. Losses range from seepage to total and financial effects, including nonproductive time and remedial operational expenses, which can increase potential risks to the operator. To address this issue, a tunable cement-based lost circulation treatment solution has been developed that is most suitable for partial to total losses, particularly when particulate-based solutions are not effective; the solution is primarily intended to cure losses while drilling. Unlike conventional lost circulation materials (LCMs) that cure losses by mechanical bridging of particles, the thixotropic cement solution's effectiveness arises from its unique chemical composition, which is ideal when flow paths are too large to be plugged by particles. The new lost circulation treatment solution is thixotropic with a density range of 10 to 15 lbm/gal working in temperatures up to 250°F. The formulation can be mixed with fresh water, seawater, or seawater with up to 14% NaCl. It is designed and tested in accordance with API RP 10B2 (2013) procedures for thickening time (TT), compressive strength, static gel strength, fluid loss, and rheology. During the TT on-off-on test, the formulation builds gel strength when shear is reduced and regains fluidity when shear is reapplied. The formulation developed rapid static gel strength and an early compressive strength up to 500 psi. The reversible gelation behavior is demonstrated through multiple shear on-off cycles. This solution is operationally convenient to apply because it can be pumped through the bottomhole assembly (BHA), thus reducing trip times. Because of its acid solubility, it can be used across production zones. The unique properties of gaining rapid gel strength reversibly and a good compressive strength render this solution effective for treating a wide range of lost circulation events during drilling. A wider density window might minimize the potential risk of inflow when treating losses.
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机译：失去流通是石油和天然气行业的经常性和昂贵的挑战。缺点范围从渗出到总和财务影响，包括非营利效度的时间和补救业务费用，这可以增加运营商的潜在风险。为了解决这个问题，已经开发了一种可调谐的水泥的丢失循环处理解决方案，最适合部分损失，特别是当基于颗粒的溶液无效时;溶液主要用于在钻井时固化损失。与常规丢失的循环材料（LCMS）不同，通过机械桥接颗粒的机械桥接，触变性水泥溶液从其独特的化学成分产生的有效性，这是理想的，当流动路径太大而不能被颗粒堵塞时。新丢失的循环处理溶液是触变性的，其密度范围为10至15磅/加仑，在温度高达250°F。该配方可以与新鲜水，海水或海水混合，含有高达14％的NaCl。它是根据API RP 10B2（2013）的增厚时间（TT），抗压强度，静态凝胶强度，流体损失和流变学的程序进行设计和测试。在TT接通试验期间，当剪切再浸渍时，配方在剪切减小并恢复流动性时，制剂构建凝胶强度。该配方开发出快速的静态凝胶强度和早期抗压强度，可达500psi。通过多剪切开关循环证明可逆凝胶化行为。该解决方案可操作地应用，因为它可以通过底座组件（BHA）泵送，从而减少旅行时间。由于其酸溶解度，它可以在生产区中使用。可逆凝胶强度的独特性质可逆地和良好的抗压强度使该解决方案有效地治疗钻井过程中的各种丢失的循环事件。更宽的密度窗口可能会在处理损失时最小化流入的潜在风险。
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