SU924080A1 - Hydrocarbon-based drilling mud - Google Patents

Description

The invention relates to the drilling of oil and gas wells, in particular to the drilling of a well bore.

Known various compositions of hydrocarbon-based drilling fluids. For example, lime-bitumen ⁵ solution containing diesel fuel, lime, highly oxidized bitumen, surfactant and water

The disadvantage of this solution ⁱⁿ yavlya- etsya use of toxic components - quick lime, which, falling on the human skin and in the process causes burns, requires protection against inhaled PU ¹⁵ minute eyes.

The closest to the present invention is a hydrocarbon-based drilling fluid containing asbestos and a surfactant [2].

A disadvantage of the known drilling mud is the difficulty of controlling the rheological and filtering. "

2

characteristics of drilling wells. With increasing temperature, the filtration loss of the solution increases dramatically, the rheological parameters deteriorate, and the weighting agent falls out. Therefore, in the process of drilling a well, the solution constantly changes its properties. Stabilization of technological parameters (especially filtration at elevated temperatures) constantly requires additional input of reagents. Therefore, such solutions can only be used in wells with bottom-hole temperatures not exceeding 80 °.

The purpose of the invention is to improve the rheological and filtration characteristics at temperatures up to 150 ° C.

This goal is achieved by the fact that the drilling rig on a hydrocarbon basis additionally contains oxidized bitumen, and as a hydrocarbon base - diesel 924030

fuel in the following ratio of components, wt.%:

Oxidized

bitumen 12.0-18.0

Asbestos O, 5 ~ 5, O

Surface active

substance 0.5 ~ 3.0

Diesel

fuel Else _ί0

The drilling fluid may contain various surfactants.

four .

substances., for example, oxidized petrolatum (CMA0) ukromin.

If necessary, the solution can be weighted to a density of 19002000 kg / m ³ .

Drilling mud is prepared as follows.

Oxidized bitumen is dissolved in diesel fuel, then a surfactant and asbestos are introduced.

Table!

Solution

Composition,

Asbestos

weight.%

Diesel

fuel

Oxidized

bitumen

Surface active

substance

one 12.0 0.5 0.50 87.0 2 15.0 2.0 1.0 82.0 3 18.0 5.0 3, about 74.0 four 10.0 0.5 0.25 89.25 five • 20.0 7.0 5.0 68.0 T a blitz 2 Indicator Solution kg / m ⁴ % cm ^th 1 ’m-Pa.s Θ Pa n ⁰ Pa one 920.0 0 ’2.20 2.40 0.20 0.40 2 940.0 0 3.20 3.20 0.30 0.85 3 1010.0 0 3.60 3.50 0.55 1.4 four 910.0 0 1.20 1.10 0 0.1 five 1100.0 0 - - - * 6 1002.0 8.0 - - 64.0 116.0 * 7 1500.0 0 6.98 1.55 0.80 1.50 eight 1500.0 0 6.10 1.90 0.60 1.40 9 1500.0 5.0 - - *

£

Due to the high viscosity of the drilling fluid determine its parameters

on the VSN-Zm and SNS-2 devices it was not possible.

5 924080

ό

In tab. 1 given the compositions of the proposed solution.

Prepare known samples of the solutions, as well as weighted oil-based and 5 drilling muds.

based on diesel fuel and oxidized bitumen with the following content of substances.

A solution of 6 wt.%: Asbestos 7.0; surface-active substance; synthetically synthesized 1% fatty acids (SMC) with a y | - hydrogen sulfide Cd-Cp 2.50; oil 90.50.

Solution 7, wt.%; oxidized bitumen, 5.50; lime CaO 10.95; water 3.40; 15

sulfonyl 0.65; barite 40.5; diesel fuel 39.0.

Solution 8, wt.%: Oxidized bitumen 8.0; Smad 1.0; asbestos 0.55; barite 53.20; diesel fuel 37.25.20

Solution 9, wt.%: Asbestos 5.0; synthetic fatty acids (FFA) 2.0; barite 48.5; oil 44.5.

Indicators of the properties of the obtained solutions are given in table. 2

(P - density, F - water loss,

1 — viscosity, co — limiting dynamic shear stress, I — limiting static shear stress).

Also, samples 7 "9 define filtering ^minutes at 150 C and 2.5 MPa pressure drop according to the method. Then the samples are subjected to mechanical strength testing at a pressure of P - 60 MPa.

The test results are presented in Table. 3

Table 3

Solution Filtration at 150 ° C and a pressure drop of 2.5 MPa (in cm) The strength of the test sample at a pressure of 60 MPa (in MPa) 7 9.0 11.0 eight 7.0 15.0 9 g ---------- Filtered out 3.5

As can be seen from the presented data, the use of diesel fuel in combination with asbestos, oxidized bitumen and surfactant ^ results in an unexpected effect, which consists in the fact that under conditions of elevated temperatures and pressures comparable to baseline ones, the stability of rocks represented by clay, highly sensitive to water. Since the core strength at 150 ° C and a pressure Rd_ - 60 MPa in a medium mud on oil basis was 3.5 MPa in an inert mud IBR - 10 MPa, and in the proposed solution - 15 MPa.Ispolzoaa- ⁵⁰ of such a solution allows to conduct trouble-free drilling during drilling in unstable clay deposits.

In the proposed drilling fluid ^{55, the} rheological and filtration properties are regulated not only by the ratio of aromatic and paraffin

hydrocarbons in a dispersion medium and a change in the degree of solvation of colloid-dispersed particles of asphaltenes, which can undergo phase transitions with temperature and pressure, but also due to the presence of inert asbestos, whose properties remain almost unchanged with increasing temperature and pressure.

Claims (1)

<claim-text> Formula of Invention </ claim-text> <claim-text> A hydrocarbon-based drilling fluid containing asbestos and a surfactant, characterized in that, in order to improve the rheological and filtration characteristics at temperatures up to 150 ° C, it additionally contains oxidized bitumen, and as a hydrocarbon base - diesel fuel in the following ratio of components, weight: </ claim-text> <table border = "1"> <tr> <td> <claim-text> 7 </ claim-text> </ td> <td colspan = "2"> <claim-text> 924080 · 8 </ claim-text> </ td> </ tr> <tr> <td> <claim-text> Oxidized bitumen </ claim-text> </ td> <td> <claim-text> 12.0-18.0 </ claim-text> </ td> <td>