RU2245895C1 - Drilling mud - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: water-based drilling mud appropriate for boring vertical, inclined, and horizontal holes contains, wt %: clay 3.0-6.9, filtration hinderer 0.1-0.3, phosphatide concentrate 1.0-1.4, sodium organosiliconate 0.1-0.5, and water - the balance. Drilling mud can further contain thinning agent, in particular nitrilotrimethylphosphonic acid.

EFFECT: decreased structural-mechanic, inhibiting, and dispersing properties of drilling mud without loss in collecting properties of bored oil-bearing beds.

3 cl, 1 tbl, 7 ex

Description

The invention relates to the drilling of oil and gas wells, namely to water-based drilling fluids for drilling vertical, directional and horizontal wells.

A well-known drilling fluid containing clay, water, a filter reducing agent, an organosilicon additive, which is used as an alkali metal organosiliconate (1).

The disadvantage of this solution is its low inhibitory properties, which is a consequence of the high alkalinity of sodium organosiliconates and the physical nature of their sorption on the surface of clay particles, slightly inhibiting their hydration. Moreover, these solutions are characterized by high surface tension of the filtrate at the “water-carbon (oil)” interface, which creates problems in the process of opening productive formations.

Closest to the claimed is a drilling fluid containing clay, water, a filter reducing agent, a lubricant additive, which is used as a phosphatide concentrate (2).

Its main disadvantage is the increased values of structural and mechanical parameters and insufficiently low values of the dispersing properties of the cuttings.

The technical result of this invention is to reduce the structural-mechanical, inhibitory, dispersing properties of the drilling fluid while maintaining the reservoir properties of the drilled oil horizons.

The technical result is achieved in that the drilling fluid containing clay, water, a filter reducing agent and a phosphatide concentrate additionally contains sodium organosiliconate in the following ratio of components, wt.%:

Clay 3.0-6.9

Filtration Reducer 0.1-0.3

Phosphatide Concentrate 1.0–1.4

Sodium Organosiliconate 0.1-0.5

Water rest

The drilling fluid may further comprise a thinner.

As a diluent, nitrilotrimethylphosphonic acid (NTP) can be used.

As a filtration reducer, CMC carboxymethyl cellulose, carbon-alkali reagent UShR, condensed sulphite-alcohol vinasse distillers KSSB are used.

The combined use of phosphatide concentrate and sodium organosiliconates allows one to obtain inhibited drilling fluid systems with a low dispersing ability of drill cuttings, with improved values of structural and mechanical properties and, at the same time, low surface tension of the filtrate at the “water-carbon (oil)” interface.

Here, the synergism between the interaction of sodium organosiliconates and phosphatide and their combined effect on the drilling fluid is manifested, which can be explained by the fact that, being adsorbed on clay, phosphatide modifies its surface in such a way that it promotes chemisorption fixation of organosiliconates on active centers of hydration of clay particles, which creates strong hydrophobic barrier that prevents clay from contacting with the dispersion medium and the dispersibility of the cuttings decreases.

This composition of the drilling fluid can prevent scree and collapse of the walls of the borehole, reduce the likelihood of sticking tools, improve the structural and mechanical properties of the flushing fluid. In addition, experiments showed that the combined presence of a phosphatide concentrate and sodium organosiliconates in a solution in combination with other components of the solution and in the claimed proportions helps to preserve the natural reservoir properties of productive formations (see table). This also shows the synergistic effect of the interaction of all components of the solution.

Drilling fluid is obtained by mechanical mixing of the components within the claimed limits of the content. A detailed description of the preparation of drilling fluids is given hereinafter in examples 1-7. After obtaining a homogeneous drilling fluid, its technological properties are determined.

The technological properties of drilling fluids are determined by standard methods on standard instruments. The inhibitory ability of drilling fluids is evaluated by the moisturizing ability index (P _o ,% / h) of specially prepared clay samples. Lubricating (anti-sticking) ability is determined in the “filter cake - metal” pair on an advanced SNS-2 instrument by the cake shear coefficient (KSK) and by the ANI standard on the Baroid Mud friction machine by determining the friction coefficient (μ _TP ) of the pair “ metal-metal ”in the medium of the drilling fluid. Structural-mechanical (rheological) properties of drilling fluids are evaluated on a VSN-3 rotational viscometer (CHC _1/10 , ∂Pa; η _square , MPa · s, τ _о , ∂Pa). The surface tension of the drilling fluid filtrate at the “water-carbon (oil)” interface is determined by the stalogmometric method by the interfacial tension index (σ, mn / m).

The composition, general technological, filtration, inhibitory, lubricating, dispersing properties of solutions are given in the table. The composition of the solutions is given in wt.%, Which corresponds to the amount of reagents in grams required for the preparation of 100 g of solution.

Example 1 (experiment No. 1). Of 92.2 g (92.2%) of water and 7 g (7%) of clay (bentopowder per dry product), a 7% clay suspension is prepared for 1 hour with stirring. Filtration reducer, for example carboxymethyl cellulose (CMC), is added in an amount of 0.3 g (0.3%), stirred for 30 minutes. Then, 0.5 ml of sodium organosiliconate (0.5%) is added and stirred for 1 hour. Then measure the parameters of the resulting clay suspension. The results of the obtained parameters are shown in the table, experiment No. 1.

Example 2 (experiment No. 2). From 90.7 g (90.7%) of water and 7 g (7%) of clay (bentopowder per dry product), a 7% clay suspension is prepared for 1 hour with stirring. 0.3 g of CMC (0.3%) is added, stirred for 30 minutes. Then 2.0 g of a phosphatide concentrate (2.0%) are added and mixed for 15 minutes. Measure the parameters of the resulting clay suspension. The results of the obtained parameters are given in the table, experiment No. 2.

Example 3 (experiment No. 3). From 92.9 g (92.9%) of water and 5 g (5%) of clay (bentopowder per dry product), a 5% clay suspension is prepared for 1 hour with stirring. Add 0.2 g (0.2%) of CMC, mix for 30 minutes. Then 1.4 g (1.4%) of the phosphatide concentrate are added and mixed for 15 minutes. Then add 0.5 ml of sodium organosiliconate (0.5%) and mix for another 30 minutes. Measure the parameters of the resulting clay suspension. The results of the obtained parameters are given in the table, experiment No. 3.

Example 4 (experiment No. 4). From 95.85 g (95.85%) of water and 3 g (3%) of clay (bent powder based on dry product), a 3% clay suspension is prepared for 1 hour with stirring. Add 0.1 g (0.1%) CMC, mix for 30 minutes. Then, 1.0 g (1.0%) of a phosphatide concentrate is added and mixed for 15 minutes. Then add 0.05 ml (0.05%) of sodium organosiliconate and mix for another 30 minutes. Measure the parameters of the resulting clay suspension. The results of the obtained parameters are given in the table, experiment No. 4.

Example 5 (experiment No. 5). From 95.4 g (95.4%) of water and 3 g (3%) of clay (bentopowder per dry product), a 3% clay suspension is prepared for 1 hour with stirring. Add 0.1 g (0.1%) CMC, mix for 30 minutes. Then 2.0 g (2.0%) of a phosphatide concentrate are added and mixed for 15 minutes. Then add 0.1 g (0.1%) of sodium organosiliconate and mix for 30 minutes. Measure the parameters of the resulting clay suspension. The results of the obtained parameters are given in the table, experiment No. 5.

Example 6 (experiment No. 6). From 87.1 g (87.1%) of water and 10 g (10%) of clay (bentroproshka per dry product), a 10% clay suspension is prepared for 1 hour with stirring. Add 0.3 g (0.3%) CMC, mix for 30 minutes. Then, 2 g (2.0%) of a phosphatide concentrate are introduced and mixed for 15 minutes. Then add 0.6 g (0.6%) of sodium organosiliconate and mix for 30 minutes. Measure the parameters of the resulting clay suspension. The results of the obtained parameters are shown in the table, experiment 6.

Example 7 (experiment 7). From 67.57 g (67.57%) of water and 30 g (30%) of clay (bent powder per dry product), 30% clay suspension is prepared for 1 hour with stirring. Add 0.3 g (0.3%) CMC, mix for 30 minutes. Then, 1.0 g (1.0%) of a phosphatide concentrate is added and mixed for 15 minutes. After that, 0.3 g of sodium organosiliconate and 0.03 g (0.03%) of a diluent, for example nitrilotrimethylphosphonic acid (NTP), are added and stirred for 30 minutes. The results of the obtained parameters are shown in the table, experiment 7.

As can be seen from the data given in the table, the drilling fluid of the proposed composition (experiments 3,5) has the best structural-mechanical, inhibitory, dispersing properties and does not have a negative effect on the formation (see σ, mn / m) compared to known drilling fluids (experience No. 1 and No. 2). The content of sodium organosiliconates in the solution of less than 0.1 wt.% Does not give an effect in improving technological parameters (experiment No. 4), and the content of sodium organosiliconates of more than 0.5 wt.% Is impractical, since there is no noticeable improvement in technological parameters (experiment No. 6 )

Thus, the data presented in the table indicate the synergistic effect of the phosphatide concentrate and sodium organosiliconates on the parameters of the clay solution,

Table Experience The composition of the solution, wt.% (Water-rest) Properties of the resulting clay solutions No. clay CMC phosphatide sodium organosiliconate thinner ρ,
g / cm ³ T, s CHC _1/10 ,
∂Pa η _square ,
MPa · s τ _about
∂Pa pH F
cm ³ KSK By,
%/hour D% σ,
mn / m 1. 7.0 0.3 - 0.5 - 1.05 37 6/14 18.0 48.0 9.5 5,0 0.20 4.8 32.8 47.1 2. 7.0 0.3 2.0 - - 1.05 45 18/42 26.0 81.0 8.7 4.0 0.11 2.6 39.14 28.3 3. 5,0 0.2 1.4 0.5 - 1,03 27 3/18 8.0 21.0 9.2 4.0 0.11 1.8 30.1 12,2 4. 3.0 0.1 1,0 0.05 - 1,02 42 18/36 25.0 79.0 8.6 4.0 0.11 2.6 39.0 - 5. 3.0 0.1 1.4 0.1 - 1,02 37 9/27 18.0 42.0 8.9 4.0 0.11 2.1 33.7 20.6 6. 10.0 0.3 2.0 0.6 - 1,07 27 25/15 8.0 18.0 10.0 4.0 0.11 1.8 30,0 - 7. 30,0 0.3 1,0 0.3 0,03 1.41 40 6/27 11.0 36.0 9.3 4.0 0.11 1.92 32.6 17.4

which makes it possible to obtain systems with improved inhibitory, dispersing and structural-mechanical properties, as well as reduce the negative impact of drilling fluids on the permeability of productive formations.

Due to the small component nature of the system, managing the properties of this flushing fluid does not present any great difficulties, which makes it possible to obtain drilling fluids with parameters preset along geological and technical parameters, including drilling of directional and horizontal sections of wells.

Used sources

1. Bulatov A.I., Penkov A.I., Proselkov Yu.M. Handbook of flushing wells, M .: "Nedra", 1984, p.55.

2. S.A. Garyan and others A.S.SSSR No. 1640141, class. S 09K 7/02, 1989, Bull. No. 13, 04/07/91.

Claims (3)

1. A drilling fluid, including clay, a filter reducing agent, a phosphatide concentrate and water, characterized in that it additionally contains sodium organosiliconate in the following ratio, wt.%: Clay 3.0-6.9 Filtration Reducer 0.1-0.3 Phosphatide Concentrate 1.0-1.4 Sodium Organosiliconate 0.1-0.5 Water Else 2. The drilling fluid according to claim 1, characterized in that it further comprises a thinner. 3. The drilling fluid according to claim 2, characterized in that as a diluent contains nitrilotrimethylphosphonic acid.