Abstract Lost circulation is a frequently encountered problem during workover operations of a low-pressure reservoir. Many lost circulation materials (LCM) have been used to solve the problem, but various disadvantages still exist, for example, oil-soluble materials are easy to get stuck in the pipe string as the temperature drops and gel time and gel strength of the cross-linking gel systems are difficult to control in the occasion of inadequate stirring. A self-breaking supramolecular plugging system used to control lost circulation of workover operations is developed, and it can encounter the aforementioned disadvantages of the traditional LCM. The system forms a space grid structure by non-covalent bonds between the molecules without adding a cross-linking agent. Sand beds plugged with the supramolecular plugging system had a pressure bearing capacity of 4.5 MPa. The self-breaking rate of the supramolecular system was 100% after 7 days at a temperature of 120°C. The core permeability recovery of the self-breaking liquid was 91.9%, indicated that the plugging system is compatible of the reservoir. The supramolecular plugging system has been used in four wells in the Jidong oilfield of East China. Field practice showed that the supramolecular LCM can effectively control lost circulation at different rates during workover operations. The increase in the daily fluid after operations indicated that the slurry has not damaged the reservoir.

中文翻译：

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一种作为油田堵漏材料的自破超分子堵漏系统

摘要 堵漏是低压油藏修井作业中经常遇到的问题。许多堵漏材料（LCM）已被用于解决该问题，但仍存在各种缺点，例如油溶性材料随着温度的下降和交叉的胶凝时间和胶凝强度容易卡在管柱中。 - 连接凝胶体系在搅拌不充分的情况下难以控制。开发了一种用于控制修井作业漏失的自破超分子堵漏系统，克服了传统LCM的上述缺点。该系统通过分子间的非共价键形成空间网格结构，无需添加交联剂。用超分子封堵系统封堵的砂床承压能力为4.5 MPa。在120°C的温度下7天后超分子体系的自断裂率为100%。自破液岩心渗透率为91.9%，表明封堵系统与储层相容。超分子封堵系统已在华东冀东油田4口井使用。现场实践表明，超分子LCM可以有效控制修井作业中不同速率的漏失。作业后每日流体的增加表明泥浆没有损坏储层。自破液岩心渗透率为91.9%，表明封堵系统与储层相容。超分子封堵系统已在华东冀东油田4口井使用。现场实践表明，超分子LCM可以有效控制修井作业中不同速率的漏失。作业后每日流体的增加表明泥浆没有损坏储层。自破液岩心渗透率为91.9%，表明封堵系统与储层相容。超分子封堵系统已在华东冀东油田4口井使用。现场实践表明，超分子LCM可以有效控制修井作业中不同速率的漏失。作业后每日流体的增加表明泥浆没有损坏储层。