CN-121993131-A - Physical simulation experiment device and method for pre-pressure energy supplementing repeated fracturing of horizontal well

CN121993131ACN 121993131 ACN121993131 ACN 121993131ACN-121993131-A

Abstract

The invention belongs to the field of oil reservoir development, and particularly relates to a physical simulation experiment device for repeated fracturing of a horizontal well before fracturing. The device also comprises a plurality of pipelines which are independent from each other, one ends of the pipelines are respectively embedded into the split positions of the first split and the second split, the other ends of the pipelines extend out of the die and are connected with the power source, the concentration of fluid flowing through the second split is higher than that of fluid flowing through the first split, and the pipelines are respectively provided with a valve and a first monitoring unit. The second monitoring units are arranged in the mould along the length direction of the pipeline in a downstream mode, cement is poured in the mould to form a simulation block, a driving source is arranged outside the simulation block, and the simulation experiment can be repeated by changing the distribution interval between the first fracture and the second fracture, the fluid injection mode and the fluid injection sequence, so that more experiment basis is provided for the repeated fracturing scheme design of oil fields and scientific research institutions.

Inventors

WANG FEI
ZHOU TAO
QI YIN
BAI XIAOHU
LI XIANGPING
DUAN PENGHUI
HUANG TING
DONG QI
YU JINZHU
REN JIAWEI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (10)

1. The physical simulation experiment device for the pre-pressure energy supplementing repeated fracturing of the horizontal well is characterized by comprising a die (1), wherein at least two first splits (2) are arranged in the die (1), at least one second split (3) is arranged in the die (1) between the first splits (2), and the size of the first splits (2) is larger than that of the second splits (3); the device comprises a die (1), a first split (2) and a second split (3), and a plurality of pipelines which are independent from each other, wherein one end of each pipeline is respectively embedded into the split of the first split (2) and the split of the second split (3), the other end of each pipeline extends out of the die (1) and is connected with a power source for providing fluid, the concentration of the fluid flowing through the second split (3) is higher than that of the fluid flowing through the first split (2), and a valve and a first monitoring unit are arranged on each pipeline; The second monitoring unit (4) is arranged in the mould (1) along the length direction of the pipeline, cement is poured in the mould (1) for shaping to form a simulation block, and a driving source for providing three-dimensional stress is arranged outside the simulation block.
2. The physical simulation experiment device for pre-fracturing energy-supplementing repeated fracturing of the horizontal well according to claim 1, wherein the first fracture piece (2) and the second fracture piece (3) are positioned on a horizontal line parallel to the long side of the die (1), and the first fracture piece (2) and the second fracture piece (3) comprise at least two wafers which are different in size and are attached to each other.
3. The physical simulation experiment device for the pre-fracturing energy supplementing repeated fracturing of the horizontal well according to claim 2 is characterized in that one end of a corresponding pipeline is nested at the joint of the wafer, and the axis of the pipeline is parallel to the long side of the die (1).
4. The physical simulation experiment device for pre-fracturing energy supplementing and repeated fracturing of the horizontal well according to claim 1, wherein the valve is a control valve.
5. The physical simulation experiment device for pre-fracturing energy supplementing and repeated fracturing of a horizontal well according to claim 1, wherein the first monitoring unit is a pressure gauge.
6. The physical simulation experiment device for the pre-fracturing energy supplementing and repeated fracturing of the horizontal well according to claim 1, wherein the second monitoring unit (4) is an optical fiber.
7. The physical simulation experiment device for the pre-pressure energy compensating repeated fracturing of the horizontal well according to claim 6, wherein at least two optical fibers are arranged on two sides of the pipeline in parallel with the pipeline, and the measuring point on the center of the optical fibers is aligned with the second fracture (3).
8. The physical simulation experiment device for pre-fracturing energy-supplementing repeated fracturing of the horizontal well according to claim 1, wherein the power source comprises a booster pump and a water tank, and the water tank is connected with a pipeline through the booster pump.
9. The physical simulation experiment device for the pre-fracturing energy supplementing repeated fracturing of the horizontal well according to claim 2 is characterized in that the arrangement angle of the first fracture piece (2) and the second fracture piece (3) and the die (1) is adjustable.
10. A simulation experiment method based on the physical simulation experiment device for the repeated fracturing of the horizontal well before fracturing, which is realized by the method according to any one of claims 1 to 9, and is characterized by comprising the following steps: Manufacturing an analog block, specifically including: At least two first split pieces (2) are arranged in the die (1), at least one second split piece (3) is arranged between the first split pieces (2), and the size of the first split pieces (2) is ensured to be larger than that of the second split pieces (3); one end of a corresponding pipeline is respectively nested with the split positions of the first split (2) and the second split (3), the other end of the pipeline is led out of the die (1) and is connected with a corresponding power source, the concentration of fluid flowing through the second split (3) is ensured to be lower than that of fluid flowing through the first split (2), and a valve and a first monitoring unit are arranged on the pipeline; a second monitoring unit (4) is arranged in the die (1) along the length direction of the pipeline in a downstream mode; pouring cement into the mould (1) for shaping, and demoulding to form a simulation block; Experimental analysis, specifically comprising: Starting a driving source to apply three-dimensional stress confining pressure to the simulation block, starting a power source respectively, injecting fluid into the first split (2) and the second split (3) in sequence until the split of the second split (3) is visible, and observing the data change of the first monitoring unit and the second monitoring unit (4); Analyzing the data of the second monitoring unit (4), and dynamically inverting the temperature, pressure, stress and strain field changes in the simulation block; The repeated simulation experiment specifically comprises the following steps: and (3) changing the distribution interval between the second split (3) and the first split (2), the fluid injection mode and the fluid injection sequence, and repeating the steps of manufacturing the simulation block and experimental analysis.

Description

Physical simulation experiment device and method for pre-pressure energy supplementing repeated fracturing of horizontal well Technical Field The invention belongs to the field of oil reservoir development, and particularly relates to a physical simulation experiment device and method for repeated fracturing by energy supplementing before horizontal well fracturing. Background As the development time of the old area of the oil reservoir increases, the yield of the old well gradually fails, but the development degree of the oil reservoir is still lower. In order to improve the yield of the old well and further improve the exploitation degree of the old oil reservoir block, a repeated fracturing transformation technology is provided. The repeated fracturing transformation technology has important significance for improving the yield of the old oil well, efficiently utilizing the old oil reservoir and converting the oil reservoir development mode. At present, the understanding of a new crack expansion rule and a new crack expansion mechanism of repeated fracturing of a horizontal well is limited, and particularly, the stress of a pressure drop funnel is changed along with the decrease of formation pressure around a primary reconstruction crack after long-term production, so that the new crack is promoted to be cracked and is not influenced by the primary reconstruction crack, and old cracks are subjected to energy supplementing before the new crack is fractured so as to balance a stress field. At present, a research mode aiming at the multi-crack expansion form of a horizontal well is relatively single, a new crack expansion rule under the old crack energy supplementing condition cannot be intuitively simulated, meanwhile, the change of a stress field in the energy supplementing and fracturing process cannot be intuitively monitored, and the new crack expansion rule under the old crack energy supplementing condition cannot be simulated and revealed. Disclosure of Invention Aiming at the problems, the invention provides a physical simulation experiment device for repeated fracturing of a horizontal well before fracturing, which comprises a die, wherein at least two first splits are arranged in the die, at least one second split is arranged in the die between the first splits, and the size of the first split is larger than that of the second split; The device also comprises a plurality of mutually independent pipelines, one ends of the pipelines are respectively embedded into the split positions of the first split piece and the second split piece, the other ends of the pipelines extend out of the mould and are connected with a power source for providing fluid, the concentration of the fluid flowing through the second split is higher than that of the fluid flowing through the first split, and the valve and the first monitoring unit are arranged on the pipeline; the second monitoring unit is arranged in the mould along the length direction of the pipeline, cement is poured into the mould to form a simulation block, and a driving source for providing three-dimensional stress is arranged outside the simulation block. Preferably, the first split and the second split are located on a horizontal line parallel to the long side of the die, and each of the first split and the second split comprises at least two wafers which are different in size and are attached to each other. Preferably, one end of a corresponding pipeline is nested at the joint of the wafer, and the axis of the pipeline is parallel to the long side of the die. Preferably, the valve is a control valve. Preferably, the first monitoring unit is a pressure gauge. Preferably, the second monitoring unit is an optical fiber. Preferably, at least two optical fibers are arranged on two sides of the pipeline in parallel with the pipeline, and the measuring point on the center of the optical fibers is aligned with the second split. Preferably, the power source comprises a booster pump and a water tank, and the water tank is connected with a pipeline through the booster pump. Preferably, the first split and the second split are arranged at an adjustable angle with the die. The invention also claims a simulation experiment method, which is realized based on the physical simulation experiment device for the repeated fracturing of the horizontal well before fracturing, and comprises the following steps: Manufacturing an analog block, specifically including: arranging at least two first splits in a die, and arranging at least one second split between the first splits to ensure that the first split size is larger than the second split size; one end of a corresponding pipeline is respectively nested with the split positions of the first split and the second split, the other end of the pipeline is led out of the die and is connected with a corresponding power source, the concentration of fluid flowing through the second split is ensured to be lower than that of fluid flow