7 results about "Displacement pressure" patented technology

The application discloses a method for determining relative permeability of loose sandstone gas and water, and comprises the following steps: drying and weighing a rock sample to obtain a dry weight, saturating the rock sample with formation water, applying a set confining pressure to obtain a wet weight, and calculating an effective pore volume of the rock sample; performing a non-steady-state gas displacement water relative permeability determination experiment on the rock sample according to a set displacement pressure difference, obtaining total sand water volume and gas volume change data over time; determining the volume of sand in the produced sand water, determining a water production volume correction coefficient according to the total sand water volume and the volume of sand in the produced sand water, and obtaining net water production volume change data over time; and determining the gas saturation of the rock sample and the gas and water relative permeability change data over time according to the effective pore volume and the net water production volume and gas volume change data over time. The method can obtain more accurate effective pore volume, accurately measure the sand volume, correct the net water production, and improve the accuracy of the determination of the relative permeability of loose sandstone gas and water.

The application relates to the technical field of unconventional oil and gas exploration, in particular to a high-clay shale oil in-situ accumulation dynamics mechanism and mode evaluation method, which comprises the following steps: collecting fluid pressure, temperature data, displacement pressure, oiliness, brittleness index, hydrostatic pressure, vitrinite reflectance and density values of shale samples at each depth position point of a probe well of each survey point; calculating abnormal sensitivity; then obtaining ground temperature evaluation credibility; obtaining self-adaptive fitting weight; obtaining actual fluid pressure of the probe well of each survey point at each depth; obtaining pressure coefficients of shale samples at each depth position point of the probe well of each survey point; obtaining self-sealing accumulation mode and retention accumulation mode of shale oil; and constructing a shale oil enrichment area evaluation comprehensive index based on vitrinite reflectance, oiliness, brittleness index and pressure coefficient to evaluate high-clay shale in-situ flow. The application improves the accuracy of evaluation of high-clay shale in-situ self-sealing accumulation, retention accumulation and dynamics mechanism.

The application discloses a pressure drive water injection flow control device, an applied pipe column and a use method, relates to the technical field of downhole tools of oil fields, and the device comprises a main body, the main body is tubular, the main body is provided with a half-through injection channel, and one port of the half-through injection channel is a water nozzle; the water nozzle comprises a water nozzle large-displacement water passing section with an unchanged width in the circumferential direction, and the water nozzle comprises a water nozzle small-displacement water control section with a gradually reduced width in the circumferential direction; the main body is connected with an injection channel opening mechanism, and the main body is connected with a water nozzle opening degree control mechanism. The half-through injection channel in the device is designed with a flow regulation structure combined with the large-displacement water passing section and the small-displacement water control section, the flow during pressure drive and conventional water injection can be accurately controlled through the water nozzle opening degree control mechanism, and the flow regulation requirements during large-displacement pressure drive and small-displacement conventional water injection can be met.

This invention relates to the field of reservoir development, specifically proposing a method for calculating the minimum miscibility pressure of CO2 based on displacement experiments. The method includes: S1: conducting CO2 displacement experiments on saturated oil samples under different displacement pressures, and testing the wax and asphaltenes content in the produced oil during the displacement experiments; S2: plotting cross-plots based on the displacement pressure, wax content, and asphaltenes content; S3: determining the minimum miscibility pressure of CO2 based on the cross-plots. This invention is the first to use displacement experiments to calculate the minimum miscibility pressure of CO2. It is based on the fact that when CO2 mixes with crude oil, it undergoes an extraction reaction with the lighter components, leading to changes in the wax / asphaltene content of the crude oil components. The minimum miscibility pressure of CO2 is ultimately determined by detecting the wax / asphaltene content in the displaced crude oil, which is simple, fast, and widely applicable.

The application provides a method for determining technical limits of effective utilization of remaining oil in a high water cut stage of a terrestrial heavy oil reservoir, and belongs to the technical field of oilfield development. The method is based on reservoir physical properties and fluid properties of a target oilfield, and uses a combination of centrifugal experiments, oil displacement experiments and core scanning technology by nuclear magnetic resonance to analyze the relationship between the flow capacity of crude oil corresponding to different pore throat radii and displacement pressure gradient, and to reveal the micro oil displacement characteristics of nonlinear seepage of the terrestrial heavy oil. A large-small pore throat parallel model is established, and the Busey flow equation is applied to study the retention mechanism of crude oil in the small pore throat and the technical limits of utilization under the main forces in the micro condition, to determine the technical limits of effective utilization of micro remaining oil, to propose a strategy for tapping the potential of remaining oil in the high water cut stage, to greatly improve the recovery rate, to greatly improve the development effect in the high water cut stage, to further develop and enrich the theory of efficient development of the terrestrial heavy oil reservoir, and to provide technical support and theoretical guidance for formulating the development technology policy of the terrestrial heavy oil reservoir in the high water cut stage.

The application discloses a kind of oil reservoir recovery enhancement methods based on microbubble oil displacement, applied to the water drive development process of low permeability reservoir;The method comprises the following steps: adding micron-sized bubbles in water injection flow, to obtain microbubble aqueous solution;The microbubble aqueous solution is injected into the oil reservoir through injection well;During the migration process of the microbubble aqueous solution into the oil reservoir, the micron-sized bubbles in the microbubble aqueous solution grow or shear to become smaller, to increase the flow resistance of the first type of permeation channel in the oil reservoir, while improving the displacement pressure of the water flow in the second type of permeation channel in the microbubble aqueous solution;The micron-sized bubbles of the application have good homogeneity and little damage to the formation;By using the micron-sized bubbles in the reservoir through the Jiamin effect, the effect of increasing viscosity and increasing pressure, the water drive swept volume of the oil reservoir is effectively expanded, the cost is low, and the recovery of the low permeability reservoir is improved, thereby achieving the purpose of increasing the crude oil production of the oilfield.

The application discloses a kind of high water cut later period medium-high permeability reservoir water injection water quality evaluation method, comprising the following steps: selecting water sample source;Develop injection water compatibility research, determine injection water oil content, suspended solids content index value, establish different grade water injection water quality standard;Establish physical simulation model and measure relevant parameters;Calculate the change value of oil displacement efficiency, displacement pressure, displacement multiple under different injection water quality conditions;Respectively establish oil content, suspended solids content and oil displacement efficiency, displacement pressure, displacement multiple relationship chart;Establish medium-high permeability reservoir high water cut later period water injection water quality evaluation standard, the application is suitable for oil and gas field development technical field, can be made with high water cut later period medium-high permeability reservoir development more suitable water quality standard, can avoid the problem of too strict water quality requirement to part of medium-high permeability reservoir, optimize water quality management scientificity, water quality promotion strategy and ground water treatment system processing efficiency, improve the economy of oilfield exploitation.