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 >

This study investigates the key factors controlling marine shale gas preservation in Devonian–Carboniferous strata, focusing on four representative synclines in the Nanpanjiang Basin and the northern margin of the Guizhong Depression: Langdai, Xinzhai, West Yizhou, and North Yizhou. Through tectonic characterization and balanced cross-section restoration, we clarify the effects of structural style, tectonic deformation intensity, and fault properties on shale gas preservation. Wide-gentle bidirectional thrust synclines (Xinzhai and West Yizhou) offer the most favorable preservation conditions, followed by the wide-gentle unidirectional thrust syncline (Langdai); the wide-gentle nappe-type... More >

Injected water quality critically determines waterflooding effectiveness. The southern area of Gaoshen, a major deep reservoir block of the Gaoshangpu Oilfield (Jidong Oilfield), faces severe injection-well plugging, increased injection pressure, failing injection rates, and rapid production decline—necessitating urgent water-quality optimization. This study conducts reservoir sensitivity evaluation, injected water–reservoir compatibility analysis, and single-factor experiments on the effects of solid particles, suspended oil, and bacteria on permeability. Results show: (1) The reservoir exhibits moderately strong water sensitivity (critical salinity: 6000--10000~mg/L); current injected-... More >

Continental saline lacustrine dolomite reservoirs remain less understood than their marine analogs. This study investigates the lower Cretaceous Tengger Formation in the western Baiyinchagan Sag, Erlian Basin, using core, thin section, SEM, XRD, isotope and petrophysical analyses. The dark muddy dolomitic rocks are composed mainly of ankerite, albite and natrolite with low clay content, indicating a mixed origin of saline lake evaporation and deep-sourced fluids. Two dolomitization types control reservoir quality: penecontemporaneous dolomitization creates intercrystalline pores, whereas burial dolomitization forms cements that block pores. Dissolution pores and high-angle fractures constitu... More >

The Triassic Halahatang Formation in the Tahe Oilfield, Tarim Basin, records a complex transition from fluvial to lacustrine depositional systems, yet its depositional architecture, evolutionary process, and controlling mechanisms remain insufficiently constrained. In this study, core observations, thin-section analysis, well-log interpretation, seismic attributes, heavy-mineral assemblages, palynological data, paleotopographic restoration, and sequence stratigraphic analysis were integrated to clarify sedimentary facies types, provenance directions, sandbody stacking patterns, and depositional evolution. The study area developed braided river, meandering river, and shore–shallow lacustrin... More >

The North Huazhou area in Weihe Basin, a transition zone between the Ordos Block and Qinling Orogenic Belt, hosts multiple Cenozoic reservoirs critical for helium, geothermal, and tight oil/gas exploration. Based on Well H1 core, logging, and laboratory data, multi-scale analyses of the Sanmen, Zhangjiapo, Lantian-Bahe Formations, and Gaoling Group reveal significant lithological differentiations: the Zhangjiapo Formation is a medium-porosity, medium-permeability reservoir, whereas the Lantian-Bahe Formation exhibits low porosity and permeability. X-ray diffraction confirms dominant siliceous minerals with clay fluctuations reflecting strong hydrodynamic environments. Moderately strong veloc... More >

Oil and gas testing laboratories have long encountered structural challenges including unclear functional roles, the disconnection between research and testing, and ongoing talent attrition, necessitating an intelligent transformation. Embodied intelligence, as an emerging paradigm integrating AI and robotics, features a local inference model of "cloud-device collaboration" that overcomes the limitations of traditional AI detached from the physical environment. Embodied intelligence enables laboratories to transition from "passive testing" to "proactive, intelligence-driven operations". Nonetheless, current deployment remains constrained by high costs and limited technological maturity. A p... 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 >