SU1677240A1 - Method for determination of circulation time during drilling - Google Patents

Abstract

The invention relates to the drilling of oil and gas wells. The goal is to reduce the likelihood of complications and reduce unproductive drilling time. The radii of the wells and the drill string are determined. The density of the rock and the flushing fluid leaving the well are measured, the average velocity of the flushing fluid in the annulus. The density of the drilling fluid entering the well, the continuous drilling time, the mechanical drilling rate is determined. The duration of the washing time is determined by a mathematical formula. The use of this method prevents the likelihood of oily formation, absorption of sticking of the column, and also improves the quality of drilling, reduces unproductive drilling time. 1L

Description

The invention relates to the drilling of oil and gas wells and is intended to determine the duration of the flush.

The purpose of the invention is to reduce the likelihood of complications and reduce unproductive drilling time.

The method is as follows.

The radii of the well and the drill string are determined, the densities of the rock and the drilling fluid leaving the well, respectively, and the average velocity of the flushing fluid in the annulus. Additionally, the density of the drilling fluid entering the well, the continuous drilling time, the mechanical drilling rate, and

the duration of the washing time is determined from the following relationship:

about

tn

one

1800

ЈL

R2

To sk

VM6 tH6

Vn -a (rvsh-rvh) - (Roc

R2

K to

)

Yu

&

where the trenches are the density of the washing liquid leaving the annular space (well), kg / m3;

RVH is the density of the drilling fluid entering the well, kg / cm3;

/ a, - rock density, kg / m3;

RCK, RK - radius of well and drillstring, respectively, m,

tH b continuous drilling time, h;

/ mb mechanical drilling rate, m / h;

Vn — average flow velocity in the annular space, m / s;

a - coefficient of proportionality, characterizing the probability of the discharge of the slag to the day surface per unit of time, is determined by the formula

the complications and reduction of the unproductive drilling time are additionally determined by the density of the drilling fluid entering the well, the continuous drilling time, the mechanical drilling rate, and the duration of the washing time is determined by the formula

but

BUT

The use of a method for determining the duration of flushing while drilling a well from drill cuttings particles suspended in the solution prevents the possibility of oily formation and absorption of sticking of a column. All this improves the quality of drilling, reduces unproductive drilling time and generally has a positive effect on the technical and economic indicators of drilling,

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A method for determining the duration of a wash when a well is drilled, including determining the radii of the well and the drill string, the density of the rock, respectively, and the flush fluid coming out of the well, and the average speed of the flush fluid in the annular space, to the fullest possible ЈL p2 g sk  Vn.6. t, m. vn "(В-р-(RCK-RK) where FIR is the density of the flushing fluid exiting the well, kg / m3; RVH — density of drilling fluid entering the well, kg / m3; RF - rock density, kg / m; RCK, RK — radii, respectively, of the well and drill string, m; tn.e. - time of continuous drilling, h; Vm.6. - mechanical drilling rate, m / h; Vn — average velocity of the flushing fluid in the annular space, m / s; a - coefficient of proportionality, which characterizes the probability of sludge removal to the day surface per unit of time, is determined by the formula thirty R