Petroleum is the irreplaceable energy source in daily life, industrial production, aerospace and military industry. As a non-renewable energy source, the development and utilization of petroleum are very important. While exploiting new oilfields, the resources of the current oilfields should be fully utilized to maintain stable production. It is therefore particularly important to use workover rigs to repair and maintain the existing wellheads. The important medium of workover is the workover fluid, which is mainly composed of mud. The success of the workover operation is related to the smooth circulation and the correct proportion (slurry preparation) of the workover fluid. The technological process and the equipment layout scheme of the workover rig projects in the recent years are researched to select the problems in the typical project for the case analysis. It is concluded that in the process of the workover fluid circulation and the slurry preparation, the different arrangement sequence of the mud tanks and the different relative positions of the mud tank and the high-pressure mud pump have the important impact on the actual construction and function realization, even resulting in the failure of the technological process due to the unreasonable arrangement of pipelines. Finally, two sets of optimization schemes are proposed based on the existing problems to provide reference in the future projects of the workover rig.