SU1337751A1 - Method of regulating water transfer of drilling fluid - Google Patents

Abstract

The invention relates to the control of drilling process parameters and can be used in the oil and gas industry. The aim of the invention is to increase the efficiency of the flow control by eliminating the repeated measurement of the current values of the flow rate by a direct method and analysis of the component composition of the solution. The drilling fluid is prepared by mixing in a certain mass ratio of its components on the basis of a given initial yield value (c) and maintaining the chosen value B by changing the component composition of the drilling fluid. Indirectly, the value of B is determined by conductometric measurement of the resistivity of the solution during drilling and varies in real time the mass of the reagent most sensitive to change B. All these operations are carried out on the basis of a predetermined relationship between the specific electric resistance B and the composition solution. 1 il. (L has conquered

Description

1133

The invention relates to the control of the parameters of the technological process of drilling oil and jazz wells and can be used to control the water loss of drilling fluids.

The aim of the invention is to increase the efficiency of the control of the yield by eliminating the repeated measurement of the current values of the yield by a direct method and analysis of the component composition of the solution.

The method is based on the definition of experience

In a production environment, the drilling fluid is prepared by mixing in a specific weight ratio.

functional way between the electrical resistivity 15 of its components (with a given value (resistivity) and the water loss of the drilling mud - the concentration of clay powder) and the specified pa. The resistivity can serve as an indirect observable parameter reflecting variations in the main factors of the state

the value of water loss B and measure the initial water loss of drilling mud V. and its resistivity

d p L J v RD. From the set of available solutions, if its mineralization by 20 pallets is chosen, the one that corresponds to (%) lies within 0.1 6 C, e. D-4. the applied concentration of clay powder (for the

Experimentally established relationships between water yield B, mineralization, amount of chemical agent (C (%) carboxymethylcellulose - CMC) in the drilling fluid at different concentrations of mud powder and drill fluid resistivity show that, for example, 8% of tech- nology).

On the graph of the chosen dependence 25 in f (p), the working point is established which lies on the curve of the B f (p) family, corresponding to the initial concentration of the chemical agent.

ecological optimal values

C) ds in the prepared drilling mud-30 (in curve 3 of the drawing), after which the solution is included in the fluid circulation system in the well, a well is drilled, during which the current values of the resistivity of the drilling mud 3 are measured; .

When drilling a well, there is a change in the component composition of the drilling fluid, its temperature or salinity, and, consequently, of its mineralization, its concentration, the concentration of the recorded value of the resistance of the chemical agent C, the most sensible and fluid loss of the drilling fluid. water loss. To eliminate the effect of changing and resistivity of the drilling fluid at different temperatures of the drilling fluid in the re-concentration of mud powder in the drilling, the resistive value of resistivity p; administered to the solution. Based on these dependencies, the 45th amendment, obtaining the current value, establishes the relationship between the water and resistivity zones; drilling mud reduced

before delivery, cm correspond to the degree of mineralization of the C aci solution 3-4%, i.e. when resistivity is an informative parameter of water return B.

The method is carried out in the following sequence.

Under laboratory conditions, the dependencies between the water yield B of the drilling solution B and UES — p drilling mud at certain concentrations of clay powder and a given concentration of chemical agent C (ddts (carboxymethylcellulose) are set in the laboratory, and a family of curves B f (p) is built for different concentrations of the chemical CMC, which strongly influences the value of water loss.

to the temperature at which the dependence B f (p) was established in the laboratory.

50 The dependence of water loss on the magnitude of the resistivity of the drilling fluid B f (p) is established laboratory at a certain fixed temperature of the solution (in the drawing at t 20 ± 1 ° С). 55 In case of temperature deviation

The drawing shows a family of drilling mud during the passage of curves B (p) at a variable well value versus temperature, at which the concentration of chemical CMC in the drilling swarm shows the dependence B f (p), the solution. introduced

Curve 1 corresponds to a one percent weight content of CMC; curve 2 - 0.75%; curve 3 - 0.5%; curve A 0, 25%. Such a set of palette curves is constructed for all used clay powder concentrations (usually 4 to 12%) in the drilling mud. Drilling mud prepared on clay bentonite

(montmorillonite) containing clay powder 8 wt.%.

In a production environment, the drilling fluid is prepared by mixing in a specific weight ratio.

its components (with the specified value of the clay powder) and the specified

its components (with the specified value of the clay powder) and the specified

the value of water loss B and measure the initial water loss of drilling mud V. and its resistivity

d p L J v RD. From the set of available palettes, choose the one that corresponds to the applied concentration of clay powder (for

example 8%).

On the graph of the chosen dependence 25 in f (p), the working point is established which lies on the curve of the B f (p) family, corresponding to the initial concentration of the chemical agent.

the amendment u p, obtaining the current value of the electrical resistivity P; corresponding to the temperature at which the dependence B f (p) was established in the laboratory.

R, . (1) The correction value is the recorded resistivity value p; (. At the temperature of the drilling fluid {determined from the expression

  - -H: P

DJ.

where t is the initial value of the temperature of the drilling fluid, at which the dependence В t (р) is established;

 Pf - resistivity value, corresponding to I о

temperature

bi. t - tp is the difference between the recorded value of the temperature of the drilling fluid and its initial value. The coefficient a is determined experimentally when building the correction curve (2) by studying the sample solution in the temperature range under study and measuring its resistivity.

The resistivity value p, and the temperature t of the drilling fluid are determined simultaneously, after which the correction 4p is calculated (or graphically), the recorded resistivity value rm is corrected, obtaining the current resistivity value pj of the drilling fluid, set in the plot of f (p) a new operating point A, (Bd, p;), which is located on the isoline of the concentration of chemical agent CMC A - and determines the mass of the reagent that is most sensitive to the change in water loss necessary to achieve the specified or maximum allowable value of water loss.

Since the resistivity of a drilling fluid changes at a given initial concentration of the chemical agent C, then the change in fluid loss B of the drilling fluid occurs along the isoline of a constant concentration C ,, | (in the drawing along line 3), The current value of water return B j in the drilling process becomes different from the specified value of water return CW and in order to maintain it at a given level (B), a certain amount of chemical CMC must be introduced into the drilling fluid. With the introduction of chemical CMC new working

point A turns out to be lying on curve B f (p) with chemical concentration С | (П || A (on drawing 2). The required amount of chemical depends on the deviation value of the current value of water loss B from the given value B. calculated graphically as the difference

C | (mi A,

Thus, when CMC is introduced into the Oura solution up to the concentration of CPC AJ, the water output of the drilling fluid, B will take the value B when

electrical resistivity p; drilling mud. Controlling the current value of the resistivity of the drilling fluid P; , regulates its water loss with the help of dosed

chemical agent additives that are most sensitive to the amount of water loss, the required volume of which is determined by the family of curves B (p),

Claims (1)

Invention Formula The method of controlling the water loss of the drilling fluid, which consists in preparing the drilling fluid by mixing in a certain weight ratio of its components, determines the initial value of water loss, includes the drilling fluid in the fluid circulation system. and maintain the value of water loss in the process of drilling a well by changing the component composition of the drilling fluid, characterized in that, in order to improve efficiency control of water loss by eliminating multiple measurements of current values of water loss by a direct method and analysis of the composition of the solution, measure the specific electric the resistance of the drilling fluid, corresponding to its initial value of the output, is measured by the current 3hu4Ci.jfo of the electrical resistivity of the solution in the drilling process of a well and the pre-established relationship between the water loss, the specific electrical resistance of the solution and its component composition determines the mass of the reagent, most sensitive to changes in water loss, necessary to achieve its maximum allowable value, smu zi Jz 30 28 26 2U 22 20 18 76/4 & S 8 6  2 o m AO, and 0.6 av J), OM.M Compiled by Yu. Korshunov Editor E. Kopcha Tehred M. Khodanych. Proofreader. Shekmar Order 4122/40 Circulation 776 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk iab., d. 4/5 Production and printing company, Uzhgorod, st. Project, 4