DD289283A5 - ADDITION TO LIBERATION FLUIDS - Google Patents

Abstract

The invention relates to an addition to relief fluids for drilling in which technical equipment adjacent to the borehole wall are limited in their mobility or completely blocked. By the sole addition of anionic n-alkyl ether sulfosuccinates of the general structure RO- (C ind 2 H ind 4 O) ind n -OC-CH (CH ind 2 COONa) -SO ind 3 Na preferably n-Kokosalkylethersulfosuccinat with a degree of oxylation of 3 is at high interfacial activity good hard water resistance achieved at the same time low foaming. The additive mentioned is added at 0.05-0.5% to the systems of water, polymer solution and oil and pumped into the borehole in a targeted manner into the nip. technical equipment; Borehole wall; Agility; Oxylierungsgrad; Surface activity}

Description

Field of application of the invention

The invention relates to relief fluids for drilling in which technical equipment adjacent to the borehole wall are limited in their mobility or completely blocked and are used to remedy this disorder.

Characteristic of the known technical solutions

During the drilling process, different technical equipment is used in the borehole. These are usually a drill string and a drilling tool for direct drilling. To stabilize the borehole wall, geothermal pipe routes are installed. To evaluate the different geological and technical conditions measuring and testing facilities are used. Due to geological conditions, there are mountain ranges with different geological pressure and mountain contents. This has the consequence that occur by pressure differences between mountain content and mud pressure on the mountains Festwerdeerscheinunqen or solidification of equipment. The elimination of these complications or production disruptions brings high economic losses that can lead to the loss of clothing and measuring equipment.

The causes of fouling are often differential pressure forces on infiltration of the drilling fluid or medium downhole into receptive formations, adhesion to the clay-containing infiltration crust, mechanical crust tightening in curved wellbore sections, or a combination of these phenomena.

By tensile tests and other mechanical operations, such as vibration shooting, reliefs and loads, rotational movements u.a.m. The aim is to solve the problem of established facilities. The circulating drilling mud is usually adjusted in its parameters to this work, z. B. by lowering the filtrate behavior or the density, so that differential pressures between the well and mountains and thus possible differential pressure solidification is avoided or completely eliminated.

Another well-known measure for solving festering phenomena in the borehole is the pumping of liberation fluids directly to the fixed point in order to bring about the changes already described by solids-free solutions or drilling fluids. For this purpose, water or polymer tubs are set, which bring about a reduction in the density on-site, oil or oil-containing tubs are pumped, which cause a lubricating effect.

Aeration of existing in the borehole flushing or inserted trays has been known and used recently (DDR-WP 263325). This type of density relief is difficult to implement in water and polymer tubs, as the air is not or only slightly bonded and after a short time by the respective tub and the above flushing column breaks through, so this method is effective only with highly viscous flushing in the borehole.

More effective is the use of surface-active substances, which are deposited on the surfaces of the filter crust and the attached drill string and pipe string. These surfactants reduce the holding force and thus the power to freeze the festtened technical equipment. Furthermore, the time to free is reduced.

The surfactants employed in differential pressure relief wells in buckets have the specific task of regulating the interfacial tension between the metal solid phases and mud crust to wet either the metal or the mud body solids.

Chemically, a distinction is made in principle between three groups of surfactants:

the anionic,

the cationic and

the non-ionic substances.

The use of cationic surfactants is avoided due to the strong adsorptive effect (hydrophobic properties). Non-ionic and anionic surfactants, on the other hand, have a high wetting effect, i. H. the ability to lower the interfacial tension at each point. To date, the use of nonionic surfactants has been predominantly carried out (US Pat. No. 4,230,587.4494610, Rum. 74573, SU 791931). The use of anionic surfactants is mostly combined with nonionic surfactants to combine the high surfactant properties of the anionic surfactants with the balanced hydrophilicity balance of the nonionic surfactants (U.S. Pat. No. 2,976,209, 3,236,222, Rum. Pat. No. 7,473, GB Pat .-Nr.2084632). The sole use of anionic surfactants is hitherto not recommended due to an assumed poor resistance to hard water. (Lit .: Diener, H., interface-active substances and their suitability as additives for drilling muds, petroleum natural gas journal 1966, P. 146-150).

Object of the invention

The object of the invention is to develop an improved and economically producible additive for liberation liquids obtained from domestic raw materials and available inexpensively in sufficient quantity.

Explanation of the essence of the invention

The object of the invention is to develop an additive for liberation liquids, which consists of the smallest possible number of components and, given a high interfacial activity, has good hard water resistance and at the same time a low foaming coefficient.

It has surprisingly been found that by a sole addition of anionic n-alkyl ether sulfosuccinates of the general structure:

RO- (C ₂ H ₄ O) _n -OC-CH (CHjCOONa) -SO ₃ Na

preferably n-Kokosalkylolhersulfosuccinat with a degree of ethoxylation of 3, wherein R represents a Alkylkettonlängengemisch of 8 to 16 carbon atoms and η is in the range of 2 to 8, given a high surface activity, a good hard water resistance with low foaming ratio is achieved. It has been found that the additive is a low cost surfactant for all types of pure water-based release fluids, polymer solutions, and water and oil based muds, which simultaneously reduces metal-to-crust holding force and improves free-wheeling force. The cited additive is added to the systems of water, polymer solution or oil with 0.05-0.5% and pumped into the borehole in a targeted manner at the nip. There, the liberation fluid remains 1-5 h. After the positive tensile tests, the tub is usually mixed into the circulating rinse or sheared out. There is also the possibility of the circulating drilling muds directly add the addition of the invention in the order of 0.2-1%, so that the tendency of the mud to Festwerdeerscheinungen in certain formations is prevented from the outset.

AusfOhrungsbeisplel

Laboratory and field measurements compare the effect of the proposed surfactant with international products. The determination of the steady-state tendency in the laboratory and the time to free the drilling equipment are used for the quality assessment of the additive for liberation fluids. In the following examples, various anionic surfactants were compared under use conditions. Product A is the n-alkyl ether sulfosuccinate, product B is an n-alkyl ether sulfonate, and product C is an n-alkyl benzene sulfonate. As comparison product D, a surfactant combination consisting of 50% by weight of nonionic surfactant (cocoalkyl polyethoxy alcohol) and 50% by weight of anionogendm surfactant B was used.

example 1

In 500 ml of water at 10 ° dH 15 g Na-carboxymethyl cellulose are stirred and swollen for 4 h at 20 ° C. The viscosity of this solution is 35OmPa · s. This solution is based on the content of washing-active substance (WAS content) with 0.5 g / l of the surfactants A, B, C and D added and mixed.

The following parameters were determined:

parameter A B C D Festwerdekoeffment Foaming number 0.045 1.6 0.15 3.7 0.18 5 0.085 1.5

The Festwertdekoeffizient is determined by an internationally known method in which a filter crust is formed and the force is determined for free pulling of a metal sheet with the addition of various liberation fluids. The foaming number is a measure of the stability of the foam formed (according to the standard 026/08 of the VEB Kombinat Erdöl-Erdgas Gommern).

Example 2

To a drilling field mud with 60g / l bentonite, 20g / l starch, 55g / l NaCl and 650g / l barite are added the surfactants A, B, C, D in the concentrations of 5g / l (based on WAS content).

The following parameters were determined:

parameter without addition A B C D Fixed Pay coefficient 0.11 0.0055 0.085 0.12 0.0095 Filtratinml 7.6 7.8 9.6 10.8 7.9 Yield point in dPa 96 142 245 307 200 expansion ratio 0 1.0 1.8 2 0.9

Filtrate and yield point are determined according to international API standards.

Example 3 During the fight against Festwerdeerscheinunnen in the Teufenbereiche from 1830m to 1840m were

used different water pans. The amount of water pumped was on a hole with 2.5 kg / m ^{3 of} the

Surfactants A. and on another well in the same well field with 4.4 kg / rn ^{3 of} the surfactant B. After a period of exposure

from 3 hours the drill set with the product A was again movable and free. In contrast, the use of B only led to a positive result after repeated treatment.

The examples show that the n-alkyl ether sulfosuccinate is superior to other known anionic surfactants and is disclosed in U.S. Pat

same conditions improved parameters can be achieved in the Festwerdeerscheinungen.

Claims (3)

1. additive for relief fluids for drilling, characterized in that the addition of an n-alkyl ether sulfosuccinate with the formula RO- (C ₂ H ₄ O) _n -CO-CH (CH ₂ COONa) -SO ₃ Na where R is an alkyl chain length mixture of 8 to 16 carbon atoms and η is in the range 2-8, predominantly 3. 2. Additive according to claim 1, characterized in that the additive is a Kr kosalkylethersulfosuccinat with a degree of ethoxylation of 3. 3. additive according to claim 1 and 2, characterized in that it is added in concentrations of 0.01-0.5% of the liberation fluid.