SU1028837A1 - Method of thnermochemical treating of hole-bottom area - Google Patents

Abstract

THERMOCHEMICAL TREATMENT OF THE WELD UNDER WELLS WELLS by sequential injection of a chemical reagent and hydrochloric acid solution through the pipe string, so that, in order to increase the efficiency of formation treatment and reduce the degree of destructive effect on the metal a column of pipes; calcium carbide is used as a chemical reagent.

Description

about

SD

X

eo

;: AE

vJ The invention relates to the oil and gas industry, in particular to secondary methods of influencing the formation by treating it in the bottomhole zone. The known method of processing the productive formation by exposing it to hydrochloric acid 1. The SdKofi method is effective only when carbonate compounds (limestone, doloMIT, magnesite) are present in the reservoir and are completely ineffective when the productive formation is represented by quartzite or heavily polluted (sandy) clays. The closest to the proposed method is the thermochemical treatment of the well bottom-hole zone by sequential injection of a chemical reagent and hydrochloric acid solution into the reservoir through the pipe string. 2 The disadvantages of the method are that hydrogen release during the reaction negatively affects the pipes and leads to increase its fragility. The purpose of the invention is to increase the efficiency of the formation treatment and reduce the degree of destructive effect on the metal pipe string. This goal is achieved by the fact that according to the method of thermochemical treatment of the well borehole zone by sequential injection of a chemical reagent and a solution of hydrochloric acid into the formation through the pipe string, calcium carbide is used as a chemical reagent. The method is carried out as follows. A suspension of calcium carbide in the hydrocarbon fluid is pumped into the formation. Then hydrochloric acid is pumped into the formation, as a result of which an exothermic reaction takes place, accompanied by a large increase in the heat and combustible gas — acetylene. The reaction proceeds in two stages, the final products being acetylene gas and highly soluble calcium chloride. CQCe, -v2.Hce-v2H,; ,, 2.H, j-i-СаСг, (- 2Й 2.0- -h30, 4KKa / v / Mc Ab,, kcal / l o bCaCe, 2 1 reaction stages CoCe2 2} liO - C2.M, j + CQCOH), 4 2 stages of reaction –HsecA (OH) ,, .H20-1 When interacting with water, 1 kg of CaSbp, the amount of heat produced is 47 kcal / 1sg. When interacting with 15% hydrochloric acid, 1 kg of calcium oxide dehydrate calcium oxide exothermic effect is 1 g, b Yucca l / kg. According to the reaction, 1 kg of calcium carbide forms 1.734 kg of calcium chloride, the total amount of heat released by over-injection of 15% hydrochloric acid is Q QCzH:. (., Coce2 476r-l20.) Kg. At the same time, the effect on the reservoir is achieved as a result of a thermochemical reaction with the formation of acetylene and strong heating, as well as the interaction of hydrochloric acid with calcium hydroxide formed, accompanied by additional heating of the reservoir. An even greater effect is achieved if the reservoir is represented by carbonate rocks, in this case an excess of 15% acid injected into the well in the second stage, reacts with carbonate rocks to form soluble calcium chloride, additional heating of the reservoir and carbon dioxide evolution. , giving an additional impetus to the gas-lift effect of the intensification of hydrocarbon production. Such a reaction has the following form: 2 ICE- -CQCO ,, CQCe2t-c02. TdOgmm IIOKKa l-Kr Sasg. The volume of acetylene from pure calcium carbide is 277.73 l / kg at 20 ° C and an atmospheric pressure of 760 mm Hg. When using technical calcium carbide used for acetylene welding, the volume of acetylene is 245-280 L / kg, depending on the size of the pieces. Calcium carbide can be replaced by magnesium carbide, which, upon interaction with water, gives methylacetylene CH ,, which is, like acetylene, a valuable product for the energy and chemical industries. It also contributes to the gas lift effect and intensifies the production of hydrocarbons. For the purpose of deep penetration of a suspension of calcium carbide in a hydrocarbon fluid into the reservoir, it is recommended to inject one hydrocarbon fluid under pressure to fracture the formation, which is especially important for low permeability reservoirs. In the implementation of the proposed method, 1 liter of calcium carbide is injected with 8 liters of 15% hydrochloric acid. The required consumption of calcium carbide for heating the productive zone depends on the thickness of the productive formation, its reservoir and thermal properties, around the bottomhole area at the level of the product horizon. The proposed method allows smooth control of the reaction of calcium carbide with water or a water-containing formation fluid before the injection of 15% hydrochloric acid. In the absence of plas310260374

The well water in the well to call the state has the following advantages:

Calcium carbide stocks in wells increase hydrocarbon extraction after calcium carbide suspension by strong and long-lasting

in the hydrocarbon fluid injects-warming up the bottomhole zone and strengthening

with water. When injected into the well vogaelift effect; The second stage of the 15% hydrochloric acid process on the reservoir yields an exothermic reaction and, accordingly, the adjustment that causes

By warming up the productive formation, the cost-effectiveness process is significantly enhanced. This pro-vi can be done at any time.

warming continues when an excess of salt geological conditions is formed

Acid Acid interacts with the formation of Calcium Chloride can be isolated

Calcium oxide hydrate from a pumped out hydrocarbon thermochemical product and used in the industrial wellbore zone treatment.

Claims (1)

METHOD OF RHEMOCHEMICAL TREATMENT OF A BOTTOM BOREHOLE ZONE • by sequential injection into a formation through a pipe string of a chemical reagent and a solution of hydrochloric acid, which is necessary in order to increase the efficiency of processing the formation and reduce the degree of destructive impact on the metal pipe column, calcium carbide is used as a chemical reagent.