Well completion and pullout composition

FIELD: oil and gas production.

SUBSTANCE: composition 61.0-68.9% petroleum or petroleum processing product, 2.0-4.7% natural fatty acid, 2.1-4.0% sodium hydroxide, and natural calcium carbonate with particle size 2 to 50 μm - the rest. Natural fatty acid employs vegetable and animal fat production waste.

EFFECT: enabled killing of well at temperatures up to 80°C with middle and low-permeable reservoirs using inexpensive and accessible domestically available materials allowing oil reservoir properties of producing formations to be preserved.

3 cl, 2 tbl, 2 ex

The invention relates to gazoneftedobyvayuschie industry, in particular to hydrocarbon compositions used in the completion and workover.

Known hydrophobic composition used for drilling and plugging of wells containing hydrocarbon liquid, water and a mixture of acetamido, monoamide synthetic and salts of fatty acids VAT residue and Ethylenediamine or polyethyleneamine (patent USSR No. 1530636, From 09 To 7/06, 23.12.1989).

The disadvantage of this structure is the complexity of its preparation, the instability at elevated temperatures. When the damping layers with low permeability of 0.03 to 0.05 μm²due to the loss of aggregate stability is the saturation of the formation water filtrate, thereby reducing the relative permeability to oil.

The closest analogue to the claimed composition is a composition for completion and kill low-temperature gas wells, containing, wt.%: gas condensate - 81,0-84,9, synthetic fatty acid FFA - 1,7-2,3, caustic soda NaOH - 0,6-1,0, mineral filler is bentonite - rest (RF patent No. 2136717, From 09 To 7/06, 10.09.1999).

The disadvantage of this structure is that when interacting with the layers in the complex physico-chemical transformations is the blockage of the pore channels of the clay particles, sod is rasimone in solution, that results in lower permeability zones. At higher temperatures weaken connections between parts of the system that leads to the loss of its aggregate stability.

Object of the invention is to provide a composition for killing wells with temperatures up to 80°With middle-and low-permeability reservoirs using cheap non-deficient domestic materials, allowing to keep the reservoir properties of productive layers.

This task is solved in that the composition for completion and workover wells containing hydrocarbon-based, fatty acid, caustic soda NaOH and mineral filler, as the hydrocarbon framework contains oil or oil processing products, as fatty acids - contains natural fatty acid, and mineral filler - natural calcium carbonate with the following ratio of components, wt.%:

Petroleum base 61,0-89,0

Natural fatty acid 2,0-4,7

Caustic soda NaOH 2,1-4,0

Mineral filler rest

As a natural fatty acid (EFA) you can use waste vegetable and animal fats (LE), and as a mineral filler is a natural calcium carbonate with a particle size of from 2 to 50 microns.

Set Appl is controlled components of the composition at elevated temperatures up to 80° With provides a new technical result is the rapid creation of more sustainable patterns. This is explained by a variety of physico-chemical interaction between the components of the composition, with a strong surface-active properties and having active centers that provides increased structural strength and durability of the system. Thus, the synergistic effect of the interaction between the components is reflected in increased aggregate stability of the system, the indicators of which are not achieved in the known solutions.

In addition, due to the presence in the composition of natural calcium carbonate with a particle size of from 2 to 50 μm in the filtering process forms a thin crust that are fixed in the process of stimulation or acid treatment, which improves the permeability of the bottom zone.

A positive factor is the technological preparation of the composition and not scarce materials.

Examples of embodiment of the invention.

Example 1 (table 1, composition No. 1): 109 ml (89 g) oil at a temperature of 20°add 2.7 g LE, stirred for 1 hour. You can dissolve LE in a small amount of oil, then mix with the remaining amount of oil. In the mixture of oil and LE introduces 2.2 ml (2.8 g) of 30%aqueous NaOH solution. The mixture is mixed in the mixer with control is Kastania static shear stress to a value no lower than 10-15 DPA. Then the solution is introduced natural calcium carbonate to increase the density of the technological solution and the strength of the system and then the composition is applied as directed.

Example No. 2 (table 1, composition No. 3): 74,4 ml (61,0 g) diesel fuel at a temperature of 20°add 2.6 g LE and stirred for at least 1 hour. Then in the mixture of diesel fuel and LE introduces 2.2 ml (2.9 g) of 30%aqueous NaOH solution. To increase the density of the technological solution and the strength of the system is introduced into a solution of natural calcium carbonate. The mixture is mixed in the mixer with control buildup of static shear stress to a value no lower than 15-20 DPA, after which the composition is applied as directed.

Rheological and filtration properties of the obtained compositions were investigated and are presented in tables 1 and 2.

Viscosity was measured on the instrument SST-5, density was determined by hydrometer or based method, the static shear stress (SNA) - based device VSN-3. The volume of the liquid phase, ethylcarbamate of the composition for 30 minutes at 20°carried out on American filter press company Baroid, and at a temperature of 75°and the differential pressure of 40 MPa on the filter press WFTU-2.

thermal stability of the composition was evaluated by heating it in a metal laboratory autoclaves at a temperature of 75°C for 24 the aces, followed by measuring the difference between the densities of the liquid at the top and bottom parts of the special cylinder (Δ ρ=ρ_bottom-ρ_top, g/cm³).

To determine the effect of composition on the rocks of the productive strata in the well bottom hole was carried out studies on the action of the filtrate on the permeability of artificial cores and determined the coefficient of restitution permeability. The work was carried out on the installation wipk-1M. The results were processed using computer programs.

Analysis of test compounds 1, 2, 3, 4, are given in tables 1, 2, illustrates the advantages of the proposed structure in comparison with prototype:

- ability to maintain aggregate stability and thermal stability to a temperature of 80°C, table 1;

- minimum damage of the reservoir, which is confirmed by experimental data of table 2 for the definition of coefficient of restitution permeability;

- as the temperature increases there is an interaction oleophilic components with the formation of Soaps that create sustainable adsorption film on natural calcium carbonate with the formation of the conjugate mylocalmachinename patterns, which leads to reduced filtering with simultaneous increase aggregate stability system up to 80°C;

- technological preparation of composition for completion and well workover;

- not scarce and low cost material is domestic production.

1. Composition for completion and workover wells containing hydrocarbon-based, fatty acid, caustic soda NaOH and mineral filler, characterized in that as uglev the portly framework contains oil or oil processing products, as a fatty acid, a natural fatty acid, and mineral filler - natural calcium carbonate in the following ratio, wt.%:

Specified petroleum base 61,0-89,0

Natural fatty acid 2,0-4,7

Caustic soda NaOH 2,1-4,0

Indicated mineral filler Rest

2. The composition according to claim 1, characterized in that as a natural fatty acids it contains waste products of vegetable and animal fats.

3. The composition according to claim 1, characterized in that it contains a natural calcium carbonate with a particle size of from 2 to 50 microns.