This study developed a shale hydration inhibitor using citric acid-based deep eutectic solvent (Cit-DES) and hexadecylammonium bromide (cetyltrimethylammonium bromide) to aid wellbore instability collapse caused by drilling of gas wells with water-based fluids. Soaking linear expansion experiments were conducted Na-bent Longmaxi formation shale, respectively. The changes in illite interlayer spacing, wettability, water absorption capacity samples before after soaking an solution evaluated,...

In order to improve the recovery effect of steam huff and puff in a super-heavy oil reservoir, displacement efficiency CO2 viscosity breaker assisted flooding was studied through in-lab experiments. The reduction mechanism for horizontal wells realized by numerical simulation. results show that (80.8%) is higher than (65.4%). technology realizes rolling replacement breaker, steam, thus effectively reducing injection pressure, expanding sweep area, i.e., region improving production rate. can...

Summary Waterless fracturing for shale-gas exploitation using supercritical carbon dioxide (scCO2) is both effective and environmentally friendly, has become an extensive research topic. Previous researchers have focused on the chemical physical properties microstructure of sandstone, carbonate, shale caprock, rather than formations. The macroscale mechanical microscale fracture characteristics Wufeng Shale exposed to scCO2 (at greater 31.8°C 7.29 MPa) are still not well-understood. To study...

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization the extraction procedure was conducted by response surface method to increase yield. Study results indicated that maximum yield 69.81 mg/g under optimum conditions enzyme concentration 0.67%, solvent-to-material ratio 16.82 mL/g, temperature 58.14 °C and time 1.89 h. activity experimental study critical micelle 0.5 g/L at 30 °C,...

Although traditional viscosity-reducer-assisted water flooding can improve heavy oil recovery, it does not have a sufficient advantage over expanding the sweep range and advancing displacement front deeply. The CO2 foam make up for lack of viscosity reducer very well in process decrease volume green-gas CO2. However, mechanism combining with is still unclear. To solve this problem, flow characteristics remaining state assisted by are analyzed. In study, an etched microglass high-temperature...

Abstract Fractured anticline reservoirs are mostly developed by a line production well located at the top position and injecting bottom position. The is often interference with multiple wells, but there little related research about interferences. To solve this problem, an extended bottom-hole pressuredrop (BHPD) response model for interfered injection wells was presented to capture gravity effect. proposed model's correctness validated software numerical simulation, low regimes were...

Petroleum engineers need real-time understanding of the dynamic information reservoirs and production in development process, which is essential for fine description oil gas reservoirs. Due to non-invasive feature electromagnetic waves, more have received attention capture dynamics with electrical resistance tomography (ERT). By measuring distribution resistivity on surface, ERT can offer subsurface media. The theory foundation technology are presented this study context monitoring reservoir...

There isn't any mature technique to develop ultra-heavy oil reservoirs in the Shengli Oilfield because of large viscosity, deep and thin layer, high rate resin asphaltene. The multi-combination exploiting is developed which combines techniques under-pressure foam flow-back, efficient oil-soluble viscosity reducer, CO2 immiscible steam huff puff. following experiments were conducted about recovery mechanism technique: (1) measuring sands suspension property washing capacity; (2) comparing...

Abstract Building a complex fracture network in deep shale gas reservoir during multicluster hydraulic fracturing is challenging. On the one hand, fractures tend to propagate along bedding planes, thus leading limited height; on other under effect of high situ stress and weak plane fractures, multihydraulic can hardly initiate uniformly. All these will jeopardize performance fracturing. This paper considers influence natural network, beddings, fracturing‐fluid leakage, stresses, builds...

The majority of edge-bottom water fault-block reservoirs in China have the problem a low recovery factor during flooding. Most them suffer from serious channeling, rapid increase cut, and sweeping efficiency. Measures need to be taken further factor, among which nitrogen foam flooding viscosity reducer technologies are highly anticipated for this purpose. To fill gap, work targets with fault blocks. First, on basis evaluating effects foaming agent reducer, 2D visual large flat physical model...

As conventional oil reservoirs are gradually being depleted, researchers worldwide progressively shifting their focus towards the development and comprehensive study of tight reservoirs. Considering that hydraulic fracturing is one main approaches for developing sandstone reservoirs, it great significance to explore mechanism spontaneous imbibition waterflooding behavior after in This research delves into analysis core samples obtained from Shahejie Formation Bohai Bay Basin. All used a...

For high temperature and salinity reservoirs, the foam formulation system is required to have better foaming capacity stability under formation conditions in tertiary EOR. In order obtain a new agent suitable for this type of oil reservoir, through compounding testing 7 common oilfield chemical agents, 15 formulated agents are tested screened. Then displacement experiment dual sand packs model was established simulate flooding process. The production dynamic high-permeability pack...

Sandy braided river deposits are widely preserved in ancient stratigraphic records and act as a significant type of hydrocarbon reservoir. Due to the frequent rapid migration channels within riverbed, sedimentary architecture is highly complex. In this paper, flume experiment was conducted reveal detailed depositional process establish fine model for sandy rivers. The result showed that (1) Three types braid channels, including lateral channel, confluence deep incised were recognized based...