RU2387689C1 - Drilling waste inertisation composition - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention aims at hardening (inertisation) neutralisation of drilling waste (spent clay mud and drilling sludge, and other core boring), containing mineral oil, heavy metals, surfactants and other contaminants. The drilling waste inertisation composition contains, wt %: cement 40-80; natural silica gel 20-60; 20% liquid glass 10-20 of a dry setting material.

EFFECT: lower labour input for preparing the drilling waste inertisation composition for neutralisation and recycling.

3 tbl, 3 ex

Description

The invention relates to the protection of the natural environment during the construction, operation and dismantling of oil and gas wells and is intended to neutralize by the method of curing (inertization) of drilling waste (spent clay drilling fluids and drill cuttings, as well as other cuttings) containing oil products, heavy metals, surfactants and other pollutants .

Known compositions used to neutralize by curing the entire volume of buried drilling waste. They are based on cement dust and gypsum production waste (see patent RU No. 2162918, IPC 7 E02D 31/02, D09D 1/00, C09K 7/02 of February 10, 2001).

The main significant disadvantages of the known composition are:

- the problem of salt utilization has not been resolved;

- a barn storage method for drilling waste is required;

- the complexity of the mixing process in the barn of the total volume of drilling waste with consolidating material.

Also known is a composition for inertizing drilling wastes based on cement and with dolomite flour (see RF patent No. 2040633, IPC EV 3/16, C09R 7/02 of July 25, 1995).

The main significant disadvantages of the known composition are:

- the need to use the barn method of accumulation of drilling waste;

- the complexity of the mixing process in the barn of the total volume of drilling waste with consolidating material;

- the need for the disposal of cured material in barns.

The closest analogue selected as a prototype of the proposed solution is a composition based on cement and other materials (see SU 1754881 from 08/15/1992, 4 pp.).

The main significant disadvantages of using the known prototype are:

- the complexity of the process of mixing the components of the composition and drilling waste;

- the problem of salt disposal has not been resolved.

The main objective of the proposed technical solution is to reduce the complexity of the preparation of the composition for inertization of drilling waste and the high efficiency of its use for the disposal and disposal of drilling waste contaminated with heavy metals, phenols, oil products and other pollutants.

The problem is solved in the invention due to the use of cement for drilling waste inertization, in addition, natural silica gel and 20% water glass in the following ratio, wt.%:

cement 40-80 natural silica gel 20-60 specified liquid glass 10-20 from dry curable material

Neither from the scientific nor from the patent literature is we aware of the existence of a composition used to inert the drilling waste containing components identical to those proposed.

As cement use Portland cement brand M-500 and other types of cement.

As a natural silica gel, flask is used - siliceous rocks containing up to 97% silica, amorphous silica (opal) and a small amount of other impurities (see the website http://www.idt-invest.ru/termin4.htm.). Opal is a water-containing colloidal silicon oxide of globular structure (Mining Encyclopedia, Volume 3, M .: Soviet Encyclopedia, 1987, p. 569).

The essential features of the proposed solution together have novelty, and the proposed composition meets the criterion of novelty for recognition of his invention. The set of essential features inherent in the claimed solution is necessary and sufficient to achieve the objectives of the invention (each of the features is necessary, but all together are sufficient). Thus, the essential features of the proposed invention as a problem directly affect the implementation of the task. The conclusion about the existence of a causal relationship between the essential features of this decision and the task being implemented is legitimate, which indicates that the claimed composition meets the criterion of "inventive step".

The proposed composition with its essential features can be implemented in an industrial environment repeatedly with a complete solution of the problem.

Hence the conclusion that the proposed solution meets the criterion of "industrial applicability" is legitimate.

The proposed composition for the inertization of drilling waste was tested in semi-production conditions for the operation of the Astrakhan gas condensate field, where most of the drilling waste is highly mineralized. The results of this testing are given below (Tables 1, 2, 3).

Example 1

Drilling wastes came to the inertization unit (industrial installation for the neutralization of sludge). Here, with the help of a paddle mixer, mechanical mixing of drilling waste with the AORCIT-IN consolidating material was carried out on the basis of Portland cement grade M 500-40 wt.% And finely dispersed (0.01-0.25 mm) active additive - flask - 60 wt.% . In quantitative terms, the consumption of curing composition was approximately 200 kg (cement - 80 kg, sorbent - 120 kg) per 1 ton of drilling waste. Then, 10% of the dry curable material was added; a hardening activator solution (100 kg per 1 ton of waste) 20% sodium liquid glass, which is a thick liquid and having the following characteristics: mass fraction of silicon dioxide - 24.8-34.3; mass fraction of iron oxide and aluminum oxide - not more than 0.25%; mass fraction of calcium oxide - not more than 0.12%; mass fraction of sulfuric anhydride - not more than 0.07%; mass fraction of sodium oxide - 9.0-12.9%; silicate module - 2.7-2.9; density - 1.36-1.5 g / cm ³ .

When the inertization mixture is mixed with drilling waste, toxic impurities are bound by a sorbent. Sorption of toxic impurities in the complex proceeds to complete neutralization (Table 1).

The addition of hardening activators (cement and water glass) makes it possible to obtain a sufficiently strong material based on the neutralized waste. The strong preservative matrix formed during hardening prevents the dissolution of toxic substances under the influence of environmental components, additionally binds them physically and chemically, and reduces the contact surface with the environment.

Table 1 The results of the analysis of the water extract extracted from the cured mixture (drill cuttings + AORSIT-IN curing compound) Name pH Dense residue,% Optical density, A Na ⁺ % Cl ^- % Ca ²⁺ % Mg ²⁺ % SO ₄ ^2- % NSO ₃ ^- % CO ₃ ^2- % Drill cuttings 8.89 42.05 0.691 9.94 9.94 1.15 0.05 1.87 0.04 0.24 Cured mixture 11.65 2.88 0.166 0.08 0.05 0.77 0,03 1,02 0.02 3.01

Example 2

Drilling wastes came to the inertization unit (industrial installation for the neutralization of sludge). Here, with the help of a paddle mixer, mechanical mixing of drilling waste with the AORCIT-IN consolidating material was performed on the basis of Portland cement grade M 500-60 wt.% And finely dispersed (0.01-0.25 mm) active additive - flask - 40 wt.% . In quantitative terms, the consumption of the curing composition was approximately 200 kg (cement - 120 kg, sorbent - 80 kg) per 1 ton of drilling waste. Then, 20% of the dry curable material was added, a hardening activator solution (200 kg per 1 ton of waste), 20% sodium liquid glass.

The results of testing the composition in example 2 are given in table.2.

table 2 The results of the analysis of the water extract extracted from the cured mixture (drill cuttings + AORSIT-IN curing compound) Name pH Dense residue,% Optical density, A Na ⁺ % Cl ^- % Ca ²⁺ % Mg ²⁺ % SO ₄ ^2- % NSO ₃ ^- % CO ₃ ^2- % Drill cuttings 8.89 42.05 0.691 9.94 9.94 1.15 0.05 1.87 0.04 0.24 Cured mixture 11.96 3.35 0,098 0.02 0.15 0.64 0.00 0.85 0,03 4.86

Example 3

Drilling wastes came to the inertization unit (industrial installation for the neutralization of sludge). Here, with the help of a paddle mixer, mechanical mixing of drilling waste with the AORCIT-IN consolidating material was performed on the basis of Portland cement grade M 500-80 wt.% And finely dispersed (0.01-0.25 mm) active additive - flask - 20 wt.% . In quantitative terms, the consumption of curing composition was approximately 200 kg (cement - 160 kg, sorbent - 40 kg) per 1 ton of drilling waste. Then, 15% of the dry curable material was added, a hardening activator solution (150 kg per 1 ton of waste), 20% sodium liquid glass.

The results of testing the composition in example 3 are given in table.3.

Table 3 The results of the analysis of the water extract extracted from the cured mixture (drill cuttings + AORSIT-IN curing compound) Name pH Dense residue,% Optical density, A Na ⁺ % Cl ^- % Ca ²⁺ % Mg ²⁺ % SO ₄ ^2- % NSO ₃ ^- % CO ₃ ^2- % Drill cuttings 8.89 42.05 0.691 9.94 9.94 1.15 0.05 1.87 0.04 0.24 Cured mixture 11.69 4.32 0.156 0.04 0.10 0.69 0.05 1.14 0,03 3.62

The product of the neutralization of drilling waste in examples 1, 2, 3 is an inert mass with the characteristics of technogenic soils corresponding to hazard class IV, which can be used as an inert soil to level the terrain, backfill barns freed from sludge, and also during road construction.

The proposed composition for the inertization of drilling waste contaminated with heavy metals, phenols, petroleum products, surfactants and other pollutants has several advantages over known similar solutions, including and before the prototype, namely:

- complete neutralization and disposal of drilling waste;

- reuse of products of neutralization and disposal of drilling waste;

- reduction of economic costs when handling drilling waste.

Claims (1)

Composition for inertization of drilling waste based on cement, characterized in that it additionally contains a finely dispersed active additive - natural silica gel and 20% liquid glass, in the following ratio, wt.%:
cement 40-80 natural silica gel 20-60 specified liquid glass 10-20 from dry curable material