FR2591657A1 - METHOD AND AGENT FOR BLOCKING THE COMING OF MINERALIZED WATER AND / OR CONTAINING ACID - Google Patents

Abstract

at. Process and agent for blocking inflows of mineralized and / or acid-containing water. b. Process characterized in that a complex treatment fluid is prepared at the surface consisting of a homogeneous aqueous solution containing 0.5 to 5% by weight of a nonionic surfactant such as an exoethylated fatty alcohol, or d 'a mixture of nonionic and ionic surfactants, such as amino salts, these mixtures not containing more than 5% by weight of ionic surfactants, and then introduced continuously, through injection wells, into a geological horizon containing water, that the injection pressure is at least 0.2 MPa lower than the fractional pressure of the horizon containing water or of the layer above it, and that the a determined volume of gas is injected in order to transform the treatment fluid into foam.

Description

"Process and agent for blocking the entry of mineralized water and / or

  The present invention relates to a method for blocking mineralized and / or acid-containing waterstorms from water-containing soil layers and, in particular, from cracked solid rocks or

  porous, in excavations or openings of mines.

  As is generally known, the inflow of water that would come from the layers of ground containing it in openings or excavations of mines,

  are avoided by extracting water from these layers.

  The appropriate methods are: well drainage at specific points; drainage by galleries; and combination of drainaqe by galleries and filter wells, and drainage through galleries and filter drains provided between the layers containing water and the

drainage galleries.

  Other methods used to prevent water ingress include those where separation trenches are provided, and the injection of blocking agents into the porous spaces of the layers which contain

  the water. In principle, the processes mentioned help to

  to keep within the limits of water inflow

  openings or excavations of mines.

  However, the above methods have important defects. They require considerable investment in materials and technology. In the

259 1657

  drainage by wells or drifts, large quantities of water are extracted through the openings of the mines, but these drainage operations have adverse effects on large areas that would not otherwise have been disturbed by the mining works. In addition to the water that is on site, water from the hydrographic

  excavations or mine openings must be continuous-

  evacuated. Mainly, blocking operations,

  Until now, great technological efforts are required

  logical, or are limited in relation to blocking depths. They also require significant expense of blocking agents, such as synthetic resins, or polymers, or similar substances, used for the blockage of porous spaces (Patents DD 21 902, DE

44,443).

  The object of the invention is to reduce or block the entrances of mineralized water and / or acid-containing layers of soil that contain it, and in particular solid rocks, cracked or porous, in the excavations or openings of mines, thereby eliminating the defects mentioned above and reducing the

  expenditure on materials that they entail.

  The invention is intended to block the entrances of mineralized water and / or acid-containing surrounding geological formations in openings or excavations mines, injecting appropriate agents

  in layers of land containing water.

  According to the invention, a homogeneous complex liquid is prepared on the surface, which is then introduced into injection wells, in order to reach

  and treat all the layers that need to be blocked.

  After the continuous injection of this liquid, by the wells, in the geological horizons containing water, including the cohesive layers which surmount them, a calculated volume of gas is injected, to form a

  dispersed agent (foam) to ensure blocking.

  The required injection pressure is at least 0.2 MPa below the fractional pressure of the geological horizons containing water or the layers above them. Technological modifications to stimulate the formation of foam will consist, for example, in injecting gas before and after the injection of the solution,

  or to alternate the gas and solution injections.

  By these methods, the formation of a dispersed medium is

particularly important.

  The treatment fluids consist of aqueous solutions of surfactants, which form finely dispersed and stable foams, having a relatively high density (p> 0.04 g / cm3) when put in contact with a gas. , and are introduced into the layers containing water and converted into foam by means of the injected gas. By using determined concentrations, a temporary barrier is established, blocking the flow of water contained in the soil, by the formation of foam by the fluid, this barrier having a specific extension which is a function of the quantity

of treatment fluid used.

  Preferably, the treatment fluids

  contain 0.5 to 5% by weight of a surfactant.

  Nonionic agents, such as oxoethylated fatty acid alcohols, or mixtures of nonionic and ionic surfactants, such as amine salts, are used, these mixtures containing not more than

  5% ionic surfactants.

  Optionally, stabilizers such as polymers, clays or kaolin minerals, or higher alcohols are added to increase the blocking effect, at a rate of 0.01 to 0.5% by weight calculated on the weight

total of the treatment fluid.

  Barriers formed by the process of

  the result of the invention is to ensure a temporary control

  sure of the water contained in the geological layer.

  Unlike current processes that require great technological efforts and large financial investments, the method according to the invention consists in blocking the water inflow by means of a foam that fills the porous spaces of a given geological horizon. This foam meets the quality requirements for stability and resistance to highly mineralized surface waters. If appropriate surfactants are used, the treatment fluids that will be produced will form stable blocking foams.

  in the porous spaces of rocks, even in conditions

  extreme pressure and temperature conditions.

  Injection of the blocking fluid and gas

  must not cause significant technological expenditure.

  aunts. The blocking method can be used separately, or in combination with known methods, such as blocking adjacent deep sub-surface water zones

at the bottom of a practiced trench.

Specific description:

  The treatment fluid, the quantity of which is 5 m3 per meter of thickness of the geological horizon giving water, and constituted by a 5% solution of a

  nonionic surfactant (such as for example the "Disper-

  gator BO "), mixed with 5 parts by weight of a surfactant

  ionic active agent (such as, for example, FCF 350), is introduced in equal portions, the number of which can go up to 5, in an operation of alternative injections of this fluid and a gas in the geological horizon containing the water, at a depth of 250 m, the incoming water being highly mineralized. To increase the blocking effect, 0.1% by weight of a polymer (TBS-0) was added to the process fluid, the calculation being made on the total amount of fluid. The pressure used to introduce the process fluid is 2.8 MPa, and the gas injection pressure is 2.8 to 3.5 MPa. By this operation, the permeability of the geological horizon containing water was reduced to 10-3 m / sec.

Claims (3)

  1) A process for blocking the entrances of water, mineralized and / or containing acid, from geological layers containing this water and, in particular, from solid, cracked or porous rocks, in the excavations or openings of the mines, characterized in that a complex treatment fluid is prepared at the surface, and then continuously introduced by injection wells into a geological horizon containing water which layers of cohesive material overlie,   that the injection pressure is at least 0.2 MPa less than   than the fractional pressure of the horizon containing water or the layer above it, and that a given volume of gas is injected to transform into foam the treatment fluid.   2) Process according to claim 1, characterized in that, whatever the composition of the substances used, these substances are injected in portions, alternating the injections of the fluid and the gas, to intensify the formation of a medium scattered for blocking.   3) Agent for] the implementation of the process   for the blockage of mineralized water and / or   acid from geological layers containing water, and in particular layers of rock containing   groundwater, these waters entering into the exca-   applications, open mines, or other mine openings, this agent being contained in a treatment fluid, characterized in that it is constituted by a solution   aqueous solution containing 0.5 to 5% by weight of a surfactant   nonionic active agent such as an oxoethylated fatty alcohol, or a mixture of nonionic and ionic surfactants such as amino salts, these mixtures containing not more than% by weight of ionic surfactants, that this medium forms a stable and finely dispersed foam as a result of the injection of a gas, this foam having a density of p> 0.04 g / cm3 and, optionally, stabilizing agents are added to increase the blocking effect. such as polymers, kaolin or clay, or higher alcohols, in portions in an order of magnitude of 0.01 to 0.5% by weight, calculated on the amount of treatment fluid