Directional perforation technology of straight wells

Directional perforation technology of straight wells combines gyro inclination survey technology with perforation technology for the purpose of directional perforation of straight wells, which is applied successfully in oil field prospecting wells in Xinjiang.

Directional perforation is implemented in the direction of maximum stratum stress:

① Perforation channel runs effectively through the crack caused by stratum stress, which improves perforation completeness coefficient and makes initial capacity of oil-gas well target stratum close to original form and reduce commissioning procedures and period of oil-gas wells.

② The limit on fracturing fluid flow could be reduced and flow friction resistance decreased during fracturing operation for the purpose of improving fracturing effect, and large crack groups series could be formed easily in near-well and far-well zones.

③ The stability of perforation channel could be increased to the maximum extent in target stratum of poor concretion and great stress difference, thus sand production rate of pay formation could be decreased effectively.

Technical indicators:

1. perforator

Perforator Name

Pressure resistance (Mpa)

Applicable inside dia. of casing (mm)

Hole density

 (holes/m)

Phase

 (°)

Temperature resistance

(/2h)

Concrete  target  detection (mm)

Bore dia.

penetration depth

DX89 directional perforator

100

120-150

16

0,180

154 (180)

9.0

543

DX102 directional perforator

95

120-180

16

0,180

154 (180)

12

856








      3、 Gyroscope

measuring range and precision

azimuthal angle: 0°~360°; error ≤±2° at angle of inclination≤50°;

angle of inclination: error ≤±0.3° at 0°~70°;

measurement mode: point measurement;

operating temperature: - 20℃ - +125℃;

pressure resistance: 70Mpa.