Seawater polymer drilling fluid

Application range:

It is generally used for drilling in the upper part of the large wellbore, and can also be used for shallow well operations with weak formation water sensitivity.

1. Basic formula (kg/m³):

Pre-hydration general soil 20~40

Caustic soda 3~5

Soda ash 1~3

PAC-HV 3~5

PF-FLO 5~10

2. Common performance:

FV: 40 ~ 60 s

MW: 1.10~1.30 g/cm³

YP: 20~35 lb/100ft2

Gel: 3~10/8~20

pH: 9~10

FL: <10~5 ml

MBT: <70 g/l

2. Maintenance treatment:

a. Add caustic soda and soda ash to the seawater to reduce the content of calcium and magnesium ions, and then add the required amount of pre-hydrated bon earth;

b. Adjust the pre-hydration soil content, dilute with water or treat with lignosulfonate, lignite, PF-THIN, etc. to control the stickiness of the mud;

c. When necessary, add biopolymer XC to increase the yield value YP and shear force Gel of the mud, and increase the amount of PAC-HV to increase the viscosity of the mud;

d. The ammonium salt NPAN can also be used to control the fluid loss of mud. When the well temperature is higher, the temperature-resistant starch PF-FLO HT can be used instead of PF-FLO, and SMP and SPNH can also be used to control the fluid loss;

e. Adding potassium chloride and PF-TEX can improve the inhibition performance of the system;

f. Add PF-LUBE or PF-BLA (plastic microbeads) to improve the lubricity of the system.