Shale gas horizontal wells in the Hongxing Block are challenged by long horizontal sections, narrow annular clearances, well-developed fractures, and the coexistence of lost circulation and wellbore collapse. Complexities such as pipe sticking, pump surging, annular blockage, and cuttings accumulation frequently occur during reaming, severely affecting operational safety and efficiency. To overcome the drawbacks of conventional empirical methods, this paper establishes four quantitative models: displacement-pressure coupling, bottomhole Equivalent Circulating Density (ECD) constraint, critical cuttings transport displacement, and drill string safety loading. An integrated reaming technology... More >

Supplementing formation energy through water injection is the main way to develop old oil fields. However, formation non-homogeneity leads to the uncertainty of waterline advancement, which generates residual oil. In order to study the effect of water injection rate on the distribution of water-driven oil, we carried out water injection simulation experiments using the Tankou oilfield as an example. The oil saturation contour maps of several time points in the water-driven oil process were plotted by determining the trend of resistance value changes. We studied the drive path during the water-driven oil process, determined the location of residual oil distribution in the plane and longitudin... More >

Extended-reach horizontal wells in continental shale formations of the Fuxing Block, southeastern Sichuan Basin, face prominent challenges, including drag and torque exceeding 50 metric tons and difficulties in weight-on-bit (WOB) transfer. Continental shale is characterized by high porosity, high permeability, distinct amphiphilic properties, and rapid performance degradation of oil-based drilling fluids (OBDF). These features lead to the formation of thick filter cakes and compacted cuttings beds, which further exacerbate abnormal drag. Existing research often focuses on single technical aspects, lacking integrated, full-cycle multi-factor coupling analysis. Based on field data from 14 dri... More >