44results about How to "Increase net pressure" patented technology

The invention belongs to the field of oil exploitation and particularly provides an oil-gas reservoir fracturing construction method. The oil-gas reservoir fracturing construction method comprises a prepad fluid stage and a main sand adding stage. According to the prepad fluid stage, fracturing liquid is injected at multiple levels of construction displacement which is increased level by level from the lowest construction displacement to the highest construction displacement; and according to the main sand adding stage, sand-carried liquid is injected at the highest construction displacement,wherein the lowest construction displacement is 45-65 % of the highest construction displacement. In the preferably-selected implementation mode, design is conducted according to different construction sections, the different fracturing liquid displacement and corresponding fracturing liquid viscosities and using quantities are adopted, the mode of different-particle-diameter variable density sandadding is adopted, by utilizing the setting effect of a supporting agent, the net pressure in cracks at the supporting agent non-setting position is increased, thus the seam making height and the supporting height of remote well cracks are increased, the flow guiding capacity of the cracks at remote wells is improved, and the progressively-decreasing speed of the single-well capacity is decreased.

The present invention provides a high-efficiency self-generated gas foam fracturing fluid and a construction method. The foam fracturing fluid is composed of a base fluid, a gas-generating fluid and a heat-generating agent, wherein the mass ratio of the base fluid, gas-generating fluid, and heat-generating agent is 100: (30‑42): (5‑9). During construction, the base fluid and the gas-producing fluid are pumped downhole together through the suction of the sand mixing truck according to the mass ratio, and the heat generating agent is pumped into the downhole along with the proppant. The invention does not need liquid nitrogen accompanying injection, simplifies the on-site process and reduces the construction cost, and a large amount of gas generated through the chemical reaction achieves the purpose of increasing the energy of the formation, improving the flow capacity of the reservoir liquid, and increasing the output. It can quickly generate a large amount of inert and safe gas, and will not produce toxic gas of nitrogen oxides, reducing construction risks. At the same time, the alkaline environment generated by the reaction product is conducive to the formation of fracturing fluid gel and the corrosion protection of downhole pipe strings. By generating foam, the Jiamin effect is used to increase the net pressure of the formation, which can quickly flow back, generate heat in the deep formation to promote gel breaking, and reduce the damage of fracturing fluid to the reservoir.

The invention discloses a volume fracturing method for activating natural fractures in a large range. Including: step (1) parameter evaluation and optimization; step (2) joint perforation operation under bridge plug; step (3) acid pretreatment operation; step (4) joint construction in low-viscosity slick water or acid slick water; (5) Construction of mixing proppant and sand to plug main cracks; step (6) construction of step-up displacement; step (7) mixed injection construction of 140-210 mesh proppant and 70-140 mesh proppant; step (8) high-viscosity construction The fracturing fluid does not add sand to flush the main fracture construction; step (9) the second and third main fracture plugging and subsequent construction; repeat steps 5) to 8); then, repeat steps 5) to 7); step ( 10) Adding sand to the main fracture with high-viscosity fracturing fluid; step (11) replacement operation. The invention can increase the complexity of fractures and the volume of stimulation during reservoir stimulation, thereby realizing high-efficiency production increase of shale gas wells.