Methods for optimizing multi-cycle pressure- separated water injection in oilfields based on improved butterfly algorithms

Patent metadata

Field	Value
Publication number	US-12486744-B2
Application number	US-202519182575-A
Country	US
Kind code	B2
Filing date	Apr 17, 2025
Priority date	Apr 23, 2024
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

Disclosed is a method for optimizing multi-cycle pressure-separated water injection in an oilfield based on an improved butterfly algorithm. The method includes: S 1 : obtaining basic data of a target water injection pipeline network; S 2 : constructing an objective function for a water injection scheme optimization model considering multi-cycle pressure-separated water injection; S 3 : establishing constraints to construct the water injection scheme optimization model considering multi-cycle pressure-separated water injection; and S 4 : solving the water injection scheme optimization model considering multi-cycle pressure-separated water injection using the improved butterfly algorithm to generate a multi-cycle pressure-separated water injection optimization scheme.

First claim

What is claimed is:

1 . A method for optimizing multi-cycle pressure-separated water injection in an oilfield based on an improved butterfly algorithm, comprising:
S 1 : obtaining basic data of a target water injection pipeline network; S 2 : constructing an objective function for a water injection scheme optimization model considering multi-cycle pressure-separated water injection; wherein the objective function is configured to minimize an energy consumption cost of a pump unit in the target water injection pipeline network, and the objective function is derived based on work performed by the pump unit on injected water during each water injection period, efficiencies of the pump unit, and an electricity price, represented by:

min
⁢
F

=

∑

i
∈

I
1

,

I
2

,

I
3

∑

j
∈
J

p
ele

⁢

γ
ij

⁢

Q
ij

⁢

H
ij

⁢
ρ
⁢
g
⁢
Δ
⁢

T
i

α
·

η
bij

·

η
cij

·

η
dij

·

η
pij

wherein, i denotes an index of a water injection period within a water injection cycle, I 1 , I 2 , and I 3 denote sets of water injection periods for a low-pressure range water injection well group, a medium-pressure range water injection well group, and a high-pressure range water injection well group within the water injection cycle, respectively, j denotes an index of a water injection pump in a water injection station, J denotes a set of indices of water injection pumps in the water injection station, P ele denotes the electricity price, ΔT i denotes a unit duration of each water injection period, γ ij denotes an on-off state of a j-th water injection pump in an i-th water injection period, Q ij denotes an outlet flow rate of the j-th water injection pump in the i-th period, H ij denotes an outlet head of the j-th water injection pump in the i-th water injection period, ρ denotes an density of the injected water, g represents a gravitational acceleration, α denotes a unit conversion coefficient, η bij denotes an operating efficiency of the j-th water injection pump in the i-th water injection period, η cij denotes a transmission efficiency of the j-th water injection pump in the i-th water injection period, η dij denotes an efficiency of a motor of the j-th water injection pump in the i-th water injection period, η pij denotes a variable frequency efficiency of the motor of the j-th water injection pump in the i-th water injection period;
S 3 : establishing constraints to construct the water injection scheme optimization model considering multi-cycle pressure-separated water injection; and
S 4 : solving the water injection scheme optimization model considering multi-cycle pressure-separated water injection using the improved butterfly algorithm to generate a multi-cycle pressure-separated water injection optimization scheme;
wherein, the water injection scheme optimization model considering multi-cycle pressure-separated water injection is a mixed-integer nonlinear programming model, and the water injection scheme optimization model is solved by performing operations including:
S 401 : based on the basic data of the target water injection pipeline network and the constraints, initializing parameters including a water injection duration of each water injection well, a count of operating pumps, an allocated flow rate of each water injection pump, a speed ratio of the each water injection pump, an efficiency of the each water injection pump, a total power of the pump unit, a total energy consumption cost of the pump unit, a cycle-level total power of the pump unit, and a cycle-level total energy consumption cost of the pump unit as an initial population of the improved butterfly algorithm using Circle chaotic mapping, the Circle chaotic mapping being represented by:

x

μ
+
1

=

mod
⁢

(

x
μ

+

b
*

-

(

a
*

2
⁢
π

)

⁢

sin
⁡
(

2
⁢
π
⁢

x
e

)

,
1

Assignees

• Univ Southwest Petroleum

Inventors

• Zhou Jun
• Liu Shitao
• Liang Guangchuan
• Shi Ye
• Peng Jinghong
• Chen Longyu

Classifications

• E21B2200/20

  Computer models or simulations, e.g. for reservoirs under production, drill bits · CPC title

• E21B2200/22

  Fuzzy logic, artificial intelligence, neural networks or the like · CPC title

• G06F2113/14

  Pipes · CPC title

• G06F2111/04

  Constraint-based CAD · CPC title

• E21B47/00

  Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) · CPC title