Study of the impact of solidifier inorganic components on the performance of a solidifiable gel plugging fluid

• This paper studied a new gelling plugging fluid system for lost circulation.
• The effects of the inorganic component of solidifier on the performance of the system.
• This paper analyzed on the outcome and microstructure of the test sample.
• This system could adjust the component percentage according to the actual leakage.

To solve the problems occurring during the treatment process in the case of any malignant lost circulation, such as the “door sealed” phenomenon, this paper studied a new type of solidifiable gel plugging fluid system. The door sealed phenomenon is caused during the addition of the blocking materials to the drilling fluid, when the weak gel fails to significantly improve the stratum bearing capacity, causing the gel plugging agent to be easily eroded. This erosion results in a lack of strength in the later period. Unlike the addition of various conventional chemical conditioning agents in the plugging fluid system, to optimally adjust the plugging fluid properties, this paper studied its impact on the system sedimentation stability, rheology, compressive strength, and so on by changing the percentage of the component substances, such as bentonite, CaO, MgO, and Al2O3, and analyzed the test samples and microstructure via X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM) tests. In the analyses, bentonite was found to be able to adjust the sedimentation stability and shear thinning behavior. In addition, the solidifiers CaO, MgO, and other components were found to be able to increase the compressive strength of the samples. The studies indicated that this system could adjust the component percentage according to the actual leakage situation of oil/gas wells to meet the construction requirements while providing a certain basis for the selection of other chemical conditioning agents.