Method for designing construction parameters of nitrogen foam-carried gravel packing in high-loss horizontal wells

A method for designing construction parameters of nitrogen foam-carried gravel packing in high-loss horizontal wells, comprising the following steps:

• S1:
• determining a nitrogen foam gas-liquid ratio Gwr and a foaming agent concentration Cf for the nitrogen foam-carried gravel packing in the horizontal wells using a reservoir fluid loss rate Rl and a packing safety index Fs;
• wherein the gas-liquid ratio Gwr is calculated by the following formula:
• G
• wr
• =
• 1
• .
• 9
• ⁢
• 37
• ·
• R
• l
• 0
• .
• 1
• ⁢
• 3
• ⁢
• 5
• ·
• F
• s
• -
• 0
• .
• 0
• ⁢
• 8
• ⁢
• 1
• ·
• T
• 0
• .
• 0
• ⁢
• 0
• ⁢
• 5
• ;
• (
• 1
• )
• the foaming agent concentration Cfis calculated by the following formula:
• {
• C
• f
• =
• 1
• .
• 5
• ⁢
• 40
• ·
• R
• 1
• 0
• .
• 2
• ⁢
• 2
• ⁢
• 8
• ·
• F
• S
• 0
• .
• 0
• ⁢
• 9
• ⁢
• 6
• ·
• T
• 0
• .
• 0
• ⁢
• 1
• ⁢
• 2
• (
• quartz
• ⁢
• sand
• )
• C
• f
• =
• 1
• .
• 3
• ⁢
• 69
• ·
• R
• 1
• 0
• .
• 3
• ⁢
• 4
• ⁢
• 7
• ·
• F
• S
• 0.099
• ·
• T
• 0.011
• (
• ceramic
• ⁢
• proppant
• )
• ,
• (
• 5
• )
• wherein T represents a reservoir temperature, ° C.;
• alternatively, the gas-liquid ratio Gwr and the foaming agent concentration Cf may be rapidly selected according to the following conditions:
• (1) when any two of the following conditions are met:
• 0.1<Rl≤0.2, 0.9<Fs≤1.2, and 55° C.<T≤60° C., Gwr=1.5;
• if quartz sand is used as a packing material, Cf=1.25%;
• if ceramic proppants are used as the packing material, Cf=1.0%;
• (2) when any two of the following conditions are met:
• 0.2<Rl≤0.35, 0.4<Fs≤0.9, and 60° C.<T≤65° C., Gwr=1.75;
• if the quartz sand is used as the packing material, Cf=1.35%;
• if the ceramic proppants are used as the packing material, Cf=1.25%;
• (3) when any two of the following conditions are met:
• 0.35<Rl≤0.45, 0.1<Fs≤0.4, and 65° C.<T≤70° C., Gwr=2;
• if the quartz sand is used as the packing material, Cf=1.5%;
• if the ceramic proppants are used as the packing material, Cf=1.35%;
• (4) when any two of the following conditions are met:
• 0.45<Rl, Fs<0.1, and T>70° C., Gwr=2.25;
• if the quartz sand is used as the packing material, Cf=1.75%;
• if the ceramic proppants are used as the packing material, Cf=1.5%;
• wherein Rl represents the reservoir fluid loss rate;
• Fs represents the packing safety index;
• and T represents the reservoir temperature, ° C.;
• S2:
• calculating an apparent density ρf and apparent viscosity μf of a nitrogen foam fluid in a washpipe-screen annulus under downhole temperature and pressure conditions;
• and
• S3:
• calculating a pumping rate and sand ratio for construction operations based on the apparent density ρf and apparent viscosity μf of the nitrogen foam fluid under the downhole temperature and pressure conditions.