METHOD OF CONTROL AND ADJUSTMENT OF DRILLING BOTTOM HOLE PARAMETRES Russian patent published in 2009 - IPC E21B47/02 E21B44/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling directional and deep walls using bottom hole navigation telemetry systems (BNS). The proposed method comprises usage of BNS, surface systems of controlling drilling conditions parametres, measuring the zenith angle at well bottom, azimuth of wallbore and whipstock location. Note here that, in first measurement effected without flushing, BNS measure the azimuth of whipstock location A₁. In the second measurement with flushing and downhole engine operated idle (with no load at the bit), BNS measure the azimuth of whipstock location A₂. In subsequent measurements with the bit loaded by drilling control station weight pickup (DCS) P_i, where i=3,4,…,n, BNS measure the azimuth of whipstock location A_i, where i=3, 4,…, n. Then proceeding from DCS readings, mechanical velocity V_i is determined, where (i=3, 4, …,n), while the BNS reaction torque pickup readings are used to determined the BNS reaction torque on the bit and the drill column (DC) twist angle is calculated as the difference in measured values of the azimuth of whipstock locations φ₂=A₁-A₂ on the bottom, where i=2, 3, 4,…, n, using BNS. The aforesaid difference depends uponc lateral moment brought about by defecting force acting upon the bit in flushing and operation of drillhole engine. Then in subsequent BNS measurements of the azimuth of whipstock location A_i, at bit load P_i (i=3, 4,…, n), measured on the surface, the DC twisting angle is determined φ_i=A₂-A₁ (i=3, 4,…,n). Now the optimum DC twisting angle is calculated φ_o=A₂-A₁ (i=3 or 4 or … or n), corresponding to criteria of drilling conditions optimisation. Further on the optimised angle of whipstock location A_yo=A_t+φ_o, is determined where A_t is the required designed azimuth, φ_o is optimum DC twisting angle, at which maximum mechanical velocity is reached. In compliance with the said maximum, whipstock is located to determine critical states of drilling process from maximum variations of whipstock location azimuth A_yo and DC twisting angle φ_I (i=2, 3, 4,…, n). Aforesaid operations are repeated after stopping the drilling, drillhole flushing, after drilling the next interval, DC spudding and drill-pipe connection.

EFFECT: simplified production accessories, transfer of bottom hole data, optimised measurements, higher accuracy and reliability of measurements expanded applications.

11 dwg, 1 ex