Multistage hydraulic fracturing has been proven to be an effective stimulation method to extract more oil from the depleted unconsolidated sandstone reservoirs in Bohai Bay, China. The offshore wellbores in this area were completed with a gravel pack...
Prolonged water injection in unconsolidated sandstone reservoirs can induce pore rearrangement and modify flow pathways, thereby affecting reservoir performance. However, quantitative characterization of pore evolution in both temporal and spatial di...
Offshore unconsolidated sandstone reservoirs suffer from severe sand production, which impairs wellbore stability and productivity. This study evaluates gravel packing in light-oil unconsolidated sandstone reservoirs in the Weizhou field. This paper...
The “Double High—Double Extra High” stage of offshore oilfields, where large pumps lift liquids, leads to a rapid rise in water concentration, which triggers a decrease in rock strength and exacerbates the risk of sand production; t...
Fine migration is widely recognized as a primary cause of production decline in unconsolidated sandstone reservoirs. Migrated fines may accumulate within pore throats and obstruct flow channels, or they may be transported into the wellbore with the p...
Aiming at the significant pore structure reconfiguration and mechanical response evolution of offshore unconsolidated sandstone reservoirs during long-term high-intensity waterflooding development, this study proposes a novel fluid–solid coupli...
The primary factor constraining the performance of unconsolidated sandstone reservoirs is blockage from particle migration, which reduces the capacity of liquid production. By utilizing logging, seismic, core–testing, and oil–well product...
Unconsolidated sandstone gas reservoirs often suffer from near-wellbore plugging, permeability contrast, and sand production after acid stimulation. This study evaluates a staged chemical process that couples limited cationic polymer sand stabilizati...
Hydrocarbon reservoirs can be subjected to temperature changes due to different processes during production. Heat injection has become an advantageous method to produce heavy oils in Canada and Venezuela because it increases oil recovery. The heat re...
Water invasion can isolate gas and reduce gas-phase mobility in unconsolidated sandstone reservoirs, complicating reserve evaluation and target selection. This study evaluates dynamic reserves and remaining gas potential in the II-2 layer group of th...
The unconsolidated sandstone is a type of rock that has poor cementation, a low strength, a high porosity, and permeability. It is highly compressible under high stress and exhibits non-linear plastic deformation during hydraulic fracturing construct...
The Sebei gas field is in the Sanhu depression area of the Qaidam Basin, which is the main gas-producing area and a key profit pillar for the Qinghai oilfield. The Sebei gas field within the Qinghai oilfield is characterized by high mud content, poor...
The permeability of reservoirs is a key factor affecting the exploitation and utilization of geothermal resources. This test used a core flow meter and other advanced experimental devices to investigate the evolution of the permeability characteristi...
One of the most challenging aspects of manipulating the flow of fluids in subsurfaces is to control their flow direction and flow behavior. This can be especially challenging for compressible fluids, such as CO2, and for multiphase flow, including bo...
Unconsolidated sandstone reservoirs, particularly in offshore and marine environments, are highly susceptible to sand production, which leads to flow-capacity degradation, plugging evolution, sand-retention instability, and erosion–corrosion da...
One of the limitations of Cold Heavy Oil Production with Sand (CHOPS) is the low recovery factor (5–15%). To target the remaining 85–95% heavy oil resources, several enhanced oil recovery (EOR) techniques, such as cyclic solvent injection...
Low gas recovery in the Sebei-2 gas field is linked to residual gas trapping under water encroachment. This study investigates the pore-scale trapping behaviour of residual gas in three types of layer: conventional, low-resistivity, and low-acoustic...
The rock coring of the reservoir in the Bohai A field is difficult. The cores of the target section in the study area are loose, making it difficult to accurately measure the core-bound water saturation. The purpose of this research was to develop an...
The Neogene Guantao Formation Reservoir in the PLOilfield is a unconsolidated sandstone with high porosity and high permeability. The reservoir diagenesis is weak and dominated by compaction diagenesis. At present, insufficient research into the rela...
Hydraulic fracturing is one of the most effective stimulation methods for unconsolidated sandstone reservoirs. However, the design of hydraulic fracturing must take into account the mechanical and stress properties of different geological formations...
Accurate estimation of in-situ stresses is a critical parameter for geo-mechanical modelling. In-situ stresses are estimated in the field from logs and frac tests. Laboratory tests are performed with cored material to estimate horizontal stress chang...
In the ultra-high water cut stage, unconsolidated sandstone reservoirs suffer from severe reservoir property time-variation, streamline solidification, and inefficient water circulation. To tackle these problems, this study takes Chengdao Oilfield Bl...
In order to comprehensively understand the complex fracture mechanisms in thick and loose sandstone formations, we have carefully developed a coupled finite element numerical model that captures the complex interactions between fluid flow and solid d...
Studies have demonstrated that heavy oil flow exhibits threshold pressure gradient (TPG) which is closely related to the permeability and viscosity of the crude oil. Also, long-term water flooding continuously alters unconsolidated sandstone reservoi...
During diagenesis, the transformation of unconsolidated sediments into a sandstone is usually accompanied by compaction, water expulsion, cementation and dissolution, which fundamentally control the extent, connectivity and complexity of the pore str...
Shallow gas is an unconventional natural gas resource with great potential and has received growing attention recently. Accurate estimation of gas saturation is crucial for reserves assessments and for development program formulations. However, such...
In petroleum, geological and environmental science, flow through porous media is conventionally studied complementarily with numerical modeling/simulation and experimental corefloods. Despite advances in numerical modeling/simulation, experimental co...
Polymer flooding is one of the most widely applied chemical enhanced oil recovery (EOR) technologies and has progressed from conventional onshore sandstone applications to increasingly challenging reservoir environments. This study reviews global pol...
The world-class Jinding deposit in SW China has ~15 Mt of Zn and Pb metals combined, in an evaporite dome containing amounts of gypsum/anhydrite. These gypsum and anhydrite are mainly located in limestone breccias (Member I), gypsum-bearing complexes...
Unconsolidated sandstone uranium deposits exploited by the in situ leaching (ISL) method, contain complex tetravalent and hexavalent uranium compounds, mostly as UO2 and UO3 oxides that have different dissolution rates in sulfuric acid solutions. Thi...
Potash is a strategically critical mineral resource essential for ensuring national food security, thereby necessitating the exploration of new deposits to sustain long-term supply. This study systematically evaluates the risk of ground subsidence as...
Lithuania is a Baltic European country which shares borders with Poland, Belarus, Latvia, and Russia and has a geothermal anomaly in the southwestern region. It consists of two main geothermal complexed, i.e., Devonian and Cambrian with a temperature...
Occasionally, a selected site suitable for landfill construction is severely protested against by locals. This issue can cause the proposed landfill to be relocated to an environmentally sensitive area. The proposed Khon Kaen waste disposal site has...
The chemical sand consolidation methods involve pumping of chemical materials, like furan resin and silicate non-polymer materials into unconsolidated sandstone formations, in order to minimize sand production with the fluids produced from the hydroc...
Water plays a vital role in the weathering process of grottoes. Precipitation is a main water source in the grotto hosting mountain rock. In this study, time-lapse electrical resistivity tomography was adopted to track the movement of infiltrated wat...
Lithuania is located on the East of Baltic sedimentary basin and has a geothermal anomaly situated in the southwestern region of the country. There are two primary geothermal complexes within the anomaly, composed of Cambrian and Devonian aquifers. T...
For the successful discovery and development of tight sand gas reserves, it is necessary to locate sand with certain features. These features must largely include a significant accumulation of hydrocarbons, rock physics models, and mechanical propert...