SU1278354A1 - Method of treating water-base drilling mud - Google Patents

Abstract

. The invention relates to the field of drilling oil and gas wells and is intended for flushing the wellbore. The purpose of the invention is to reduce the dispersing ability of the drilling fluid during the drilling of clay rocks and to increase its clay content. A previously prepared alkaline humate reagent is injected into a water based drilling solution in an amount of 2.0-10.0 wt.%. Immediately before the introduction of the alkaline humate reagent, an aqueous solution of an inorganic or low molecular weight aliphatic carboxylic acid, or an inorganic acid, or a hydrolysis reagent is added to it (L value of hydrogen index in the range of 4.5-7.5. Concentration of aqueous solution of inorganic or organic acids 5-10 wt.X. Introduction of modified alkaline reagent to the drilling fluid reduces peptizing action of the solution. 2 tab.

Description

The invention relates to the field of drilling oil and gas wells, in particular to the washing of the wellbore.

The purpose of the invention is to reduce the dispersing ability of the drilling fluid during the drilling of clay rocks and increase its clay content.

The method for treating a water based drilling mud is carried out in the following sequence. Immediately prior to the introduction into the buccal solution, the alkaline humate reagent is mixed with an aqueous solution of a low molecular weight aliphatic carboxylic acid or an inorganic acid or hydrolyzed lignin.

An alkaline humate reagent is either obtained by mixing a humate-containing substance (coal coal, peat, sapropel), or using reagents derived from them - carbon alkali reagent (UShR), peat alkali reagent (TSR).

Inorganic acids, such as sulfuric, hydrochloric, nitric, etc., or low molecular weight aliphatic carboxylic acids, such as acetic acid, oxalic acid, tartaric, or hydrolysis lignin, can be used to modify (acidify) the alkaline humate reagent.

In tab. Figure 1 presents data showing a change in the rheological properties of drilling fluids depending on the sequence of input of reagents into the drilling fluid.

In tab. 2 shows the data characterizing the effectiveness of the proposed method of processing various types of water-based drilling fluids.

Example 1. 20 g of KOH are dissolved in 100 ml of water, and then 30 g of brown coal are introduced and stirred for 1 hour. 25 g of the resulting hydro-alkaline mixture, having a pH of 10.3, is treated with 5 After a 10-minute stirring, a modified aqueous humor, pH 5.0, is injected into the drilling fluid.

Example 2. In a 100 ml of water, 30 g of ASCR (pH 10.1) is dissolved in a alkali slurry and modified with 10 ml of 10% acetic acid (pH 6.0) and introduced into the drilling fluid.

0 5

0

about

0

five

Example 3. In 25 ml of 20% T11IP (pH 9.8), 5 g of hydrolysis lignin are introduced, stirred for 20 minutes. After this, a modified humate (pH 5.4) reagent is injected into the drilling fluid.

The obtained modified humate reagents are introduced into 250 ml of mud drilling mud containing 10% kaolin clay powder, 2% bentonite clay powder (the parameters of the solution are shown in Table 1, experiment 1). After that, 20% clay powder is introduced into the solution and, by changing the structural and viscous characteristics, the reduction of the peptizing effect of modified humate reagents is judged.

In tab. 1 also shows the effect of modified humate reagents on mineralized clay solution (1-0% kaapin clay mud + 2% bentonite + 5% NaCl + 0.2% CMC-600), asbestos-polymer (2% asbestos + 0.7% CMC- 600 + 0.4% Al, j (Sq,) g + + 0.1% NaOH) and clay solution, stabilized with acrylic polymers (5% bentonite + 0.3% PC-2 reagent, including 10 ma.h. 8 % piacrylamide and 1.5 wt.h. NaOH).

This effect is provided in the pH range of 4.5 to 7.5 of the treated humate reagent. For example, at a pH below 4, the yield of treated solutions increases dramatically with coagulation thickening at the same time (Run 13). At pH values of 7.5, an increased thickening of the solution is observed (test 10). This effect is explained by micelle formation in solutions of humate substances, which are micellar electrolytes. At elevated pH, the humate reagents are in a dissociated state and thicken the system strongly when ingested with clay. A decrease in pH leads to micelle formation — associates are formed, and, the higher the molecular weight of humic substances, the more likely they are to form micelles, which are effective clogging agents that reduce filtration, low molecular weight fractions of humic substances provide an inhibitory effect. A decrease in pH below 4 „5 leads to the formation of humic acids, which do not provide stac3127835A4

bilization of the colloidal system, and the reagent in the amount of 20- falls into the sediment.

The acid concentration is chosen 510%. At acid concentrations below

Claims (3)

The invention relates to the field of drilling oil and gas wells, in particular to the washing of the wellbore. The purpose of the invention is to reduce the dispersing ability of the drilling fluid during the drilling of clay rocks and increase its clay content. The method for treating a water based drilling mud is carried out in the following sequence. Immediately prior to the introduction into the buccal solution, the alkaline humate reagent is mixed with an aqueous solution of a low molecular weight aliphatic carboxylic acid or an inorganic acid or hydrolyzed lignin. An alkaline humate reagent is either obtained by mixing a humate-containing substance (stormy coal, peat, sapropel), or using reagents derived from them - carbon alkaline reagent (UShR), peat alkali reagent (TChR). Inorganic acids, for example, sulfuric, hydrochloric acid, nitrogen, etc., or low molecular weight aliphatic carboxylic acids, such as acetic acid, oxalic acid, tartaric acid, or lignin hydroline, can be used to modify (acidify) alkaline humate reagent. In tab. Figure 1 presents data showing a change in the rheological properties of drilling fluids depending on the sequence of input of reagents into the drilling fluid. In tab. 2 shows the data characterizing the efficiency of the proposed method of processing various types of water-based drilling fluids. Example 1. In 100 ml of water, 20 g of KOH are dissolved, and then 30 g of brown coal are added and stirred for 1 hour. 25 g of the resulting alkaline alkaline mixture, having a pH of 10.3, is treated with 5% - After a 10-minute stirring, the modified reagent, whose pH is 5.0, is introduced into the drilling fluid. Example 2. In 100 ml of water dissolve 30 g of ANSAR (pH 10.1) hydro-alkaline suspension is modified with 10 ml of 10% acetic acid (pH 6.0) and injected into the drilling fluid. Example 3. In 25 ml of 20% T11IP (pH 9.8), 5 g of hydrolysis lignin are introduced, stirred for 20 minutes. After this, a modified humate (pH 5.4) reagent is injected into the drilling fluid. The resulting modified humate reagents are introduced into 250 ml of mud drilling mud containing 10% kaolin clay powder, 2% bentonite clay powder (the parameters of the solution are shown in Table 1, Test 1). After that, 20% clay powder is introduced into the solution and, by changing the structural and viscous characteristics, the reduction of the peptizing effect of the modified humate reagents is judged. 1 also shows the effect of modified humate reagents on mineralized clay solution (1-0% koapin clay mud + 2% bentonite + 5% NaCl + 0.2% CMC-600), asbestos-polymer (2% asbestos + 0.7% CMC-600 + 0.4% Al, j (Sq,) g + + 0.1% NaOH) and clay solution, stabilized with acrylic polymers (5% bentonite + 0.3% PC-2 reagent, including 10 parts by weight. 8% - paryacrylamide and 1.5 parts by weight of NaOH). This effect is provided in the pH range of 4.5 to 7.5 of the treated humate reagent. For example, at a pH below 4, the yield of treated solutions increases dramatically with coagulation thickening at the same time (Run 13). At pH values of 7.5, an increased thickening of the solution is observed (test 10). This effect is explained by micelle formation in solutions of humate substances, which are micellar electrolytes. At elevated pH, the humate reagents are in a dissociated state and thicken the system strongly when ingested with clay. A decrease in pH leads to micelle formation, associates are formed, and the higher the molecular weight of humic substances, the more likely they are to form micelles, which are effective clogging agents that reduce filtration, low molecular weight fractions of humic substances provide an inhibitory effect. A decrease in pH below 4 ± 5 leads to the formation of humic acids, which do not ensure the stabilization of the colloidal system, but precipitate. The acid concentration is chosen 510%. At acid concentrations below 5%, a diluted product is obtained, 5 which does not provide the necessary properties for the drilling mud. The use of concentrated acid (more than 10%) impairs the properties of the drilling fluid, in addition, processing of the humate reagent is possible. Claims A method of treating a water-based drilling fluid, comprising introducing into the drilling fluid a previously prepared alkaline humate 35A4 reagent in an amount of 2010, 0 wt.%, Characterized in that, in order to reduce the dispersing ability of the drilling fluid P, to drill clay and increase its clay intensity, just before introducing an aqueous solution of an inorganic or low molecular weight aliphatic carboxylic acid or hydrol into the alkaline humate reagent directly into the drilling fluid. zny lignin to pH value in the range 4.5-7.5, wherein the concentration of the aqueous solution of an inorganic or low molecular weight aliphatic carboxylic acid of 5-10 wt.%. Cotplespo mshmtyugv RMGSYATS X from av% y (lump; rmgs tatil. 1 GPNYAKSPY I1 "" P 1U ", (, 7 30 oMmtMyokaTschromishA 3.2 2 1 nrMLtmA pur icrJ (7) General Assembly (P2.106.0 O.F.) (P 2.10U6.0 O.F. .i AevmtoM pripM Ittfüfomim gumatyuyu (to) 0.31.512.09.1 Io and proPoA 0,2I.e12,07, a glittM pMrtiiT2 (12) rimatCTWI nOtCMrfl 3O.S4,04.9 in the United States 50.34.0lO.t Ma f vm m 2 4) I, S0.34.0eO Pr 1s «« 111Я1.) - st stichka and lunpimcimo sd p, 1 t in n 2 caste, t, - dngani e “about“ sprzheyu edmp, in - etapsko f - Anltmsh. 2.02.912.02.0 ", 2 e.22.t0,520.0" .7 ".0 2.0O.E14.0," 18.08.9 "." 14.07, (14.0e, "5.012.0f, l 11.24 , J1,812.07. RImiMftpNND ICMM 264.52.) 2.08.2