JP3091479B2 - Water loss prevention method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Industrial Application Field The present invention relates to drilling wells for drilling wells using water-clay drilling fluids such as oil drilling wells, natural gas drilling wells, and geothermal drilling wells. The present invention relates to a water loss prevention method for effectively preventing water loss.

b. Conventional technology In recent years, the rotary excavation method has many advantages, and it is recognized that it is highly versatile.

In this rotary drilling method, a drill is attached to the lower end of a hollow pipe (hereinafter referred to as "drill string"), and the drill bit is used to break the rock in the stratum by rotating the drill string and the bit. Drilling waste (hereinafter referred to as "cuttings") is drilled through a well while carrying it out with drilling fluid. At this time, the cuttings in the stratum crushed by the bit have to be carried to the surface of the ground, and the drilling fluid (hereinafter, referred to as “muddy water”) plays the role.

As the mud, generally, water-bentonite suspension is mainly used, and if necessary, a dispersant, polymers,
A mixture obtained by adding and mixing a lubricant, a surfactant, a weighting agent and other various modifiers is used.

The cuttings are carried out by pumping the muddy water through the drillstrings using a pump and jetting it out from the tip of the bit, thereby cooling the bit and raising the muddy water together with the cuttings to the surface between the pit wall and the drillstrings. This is done by letting

However, if the mud circulated by the pump during excavation encounters a low-pressure layer, fissure, crack, or porous layer in the formation (hereinafter referred to as the “discharge layer”), the mud will penetrate into the formation. This causes a phenomenon in which normal circulation of mud cannot be ensured. This is called Itsumi.

c. Problems to be Solved by the Invention When a well encounters an aquifer, mud penetrates into the formation and the circulation of the mud becomes insufficient, hindering the removal of cutting from the mine and making the mine uncleanable. Will be possible. In other words, because cuttings in the mine cannot be removed and removed, drill strings are detained, and most of the mud escapes to the drainage layer. I do. Thus, it is extremely important to completely block the lost water layer.

Until now, for example, a capsule or the like enclosing a reactant solution is lowered into a borehole, and the capsule and the like are ruptured with an explosive against the lost water layer, so that a crack in the lost water layer has a multi-bubble structure. A method of filling a gel substance has been proposed (JP-B-58-41397). However, this method is not suitable for preventing water loss under high temperature and high pressure. For example, as a capsule,
PVC pipe, glass plate, PVC film, etc.
This is because a relatively weak material is used for high-temperature and high-pressure conditions. In addition, this method causes the capsule to rupture, so that the capsule portion cannot be reused.

That is, under high temperature and high pressure conditions (70 ° C or higher, 20 kgf / cm ²
It was difficult to prevent the water loss in the above-mentioned method) by the conventional water loss prevention method.

In view of such circumstances, the present inventors have conducted intensive studies and as a result, put the polyisocyanate component and the polyol component constituting the polyurethane foam and / or the polyisocyanurate foam in separate containers, and have dedicated I came up with a method to prevent water loss by foaming polymerization using an injector.

d. Means for Solving the Problems The present invention provides a solution containing an organic polyisocyanate having an active isocyanate group, a polyol obtained by addition-polymerizing an alkylene oxide to a compound having two or more active hydrogens, a catalyst, A foaming agent, and a solution prepared by mixing and adjusting a foam stabilizer, if necessary, are housed in separate solutions, and a dedicated injector equipped with the container is lowered into a well, and each solution is cooled to 70.
℃ above, 20kgf / cm ² (about 19.4 atmosphere) ~60kgf / cm ² (about 5
(8.2 atm), contact mixing and foaming in the area of the water layer under the conditions of high temperature and high pressure (8.2 atm) to harden the obtained low density polyurethane foam and / or polyisocyanurate foam. It is an object of the present invention to provide a method for preventing a lost water layer under a high temperature and a high pressure from being effectively blocked.

According to the water loss prevention method of the present invention, each container of the dedicated injector having two containers has a solution mainly containing a polyisocyanate containing an isocyanate group (NCO group) and an active hydrogen. A polyol containing a hydroxyl group (OH group) is filled with a catalyst, a foaming agent, a foam stabilizer, and a solution obtained by mixing and adjusting other auxiliaries as necessary,
The exclusive injector is lowered into the well and the above 2
The different types of solutions can be discharged, contact-mixed and foamed, penetrated and hardened in the drainage layer to close the drainage layer.

As the organic polyisocyanate, an aromatic polyisocyanate, an aliphatic polyisocyanate monomer mixture, a composition, or a modified product thereof can be used. The most preferred organic polyisocyanates are aliphatic polyisocyanates, and more specifically, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, dicyclohexylmethane diisocyanate, and the like.

The reason why the aliphatic polyisocyanates are most preferable among the organic polyisocyanates can be explained as follows.

That is, the formation reaction of the polyurethane foam and / or the polyisocyanurate foam sufficiently progresses under the environmental conditions in the drilling well when the water loss prevention method of the present invention is performed, and causes a sufficient volume expansion. Polyurethane foam and / or polyisocyanurate foam, a hydroxyl group-containing polyol having active hydrogen and a foaming agent added to the polyol component liquid,
The polyisocyanate is obtained by causing a foaming polymerization reaction, which is accompanied by a considerably high exothermic reaction in the course of the reaction. This has the characteristic that the reaction rate is further increased and the curing proceeds more. Therefore, when the environmental conditions in the wellbore are considerably high temperature and high pressure, it is necessary to control the rate of the foam polymerization reaction in order to delay the curing time. Among polyisocyanates, aliphatic polyisocyanates have a lower reaction rate than aromatic polyisocyanates. Therefore, aliphatic polyisocyanates are effective for controlling the foaming polymerization reaction.

The organic polyisocyanate has an NCO / OH equivalent ratio to the polyol of the present invention of 0.5 to 5.0, preferably 0.8 to 1.5.
It can be used after being adjusted to the range described below.

The polyol is obtained by addition-polymerizing an alkylene oxide to a compound having two or more active hydrogens, and is conventionally used in the production of a soft, semi-rigid or rigid polyurethane foam. be able to. Specifically, polyether polyol,
Examples include polyester polyols and polymer polyols.

However, preferred polyols in the present invention are polyether-based and polyester-based polyols obtained by addition-polymerizing an alkylene oxide to a compound having two or more active hydrogens, such as low-molecular-weight polyhydric alcohols and polyamines. It is preferably a polyether polyol having 2 to 8 functional groups and a hydroxyl value (mg KOH / g) of 200 to 6
00, more preferably those having 3 to 4 functional groups and a hydroxyl value (mg KOH / g) of 350 to 500, and one or a mixture of one or more polyols selected from these. Either can be used.

As the catalyst, those conventionally used can be used. Specifically, as basic substances such as salts of tertiary amine weak acids, monoethanolamine, diethanolamine, triethanolamine, dimethylmonoethanolamine, diethylmonoethanolamine,
There are tertiary amines such as triethylenediamine, tetramethylethylenediamine, tetramethylpropanediamine, tetramethylbutanediamine, tetramethylhexanediamine, and pentamethyldiethylenetriamine, and as an organic metal compound, stannas octoate, dibutyltin dilaurate, dibutyltin Examples include diacetate, dimethyltin mercaptide, dibutyltin mercaptide, tetrabutyl-1,3-diacetoxystannoxane, tetrabutyl-1,3-dilauroyloxydistannoxane, and the like.
These catalysts can be used alone or as a mixture of two or more. The most preferred catalyst is an organotin catalyst, which is used in an amount of about 0.1 to 0.5 part by weight based on 100 parts by weight of the polyol.

As the foaming agent, those conventionally used as foaming agents can be used. Specifically, it is a low-boiling-point inert blowing agent such as trichloromonofluoromethane and dichloromonofluoromethane, and water, a compound containing water of crystallization, and the like can also be used. The amount of the blowing agent can be empirically determined according to the type of the blowing agent.

As the foam stabilizer, any substance can be used as long as it is a substance conventionally known as a foam stabilizer. In particular, a silicone-based foam stabilizer is effective, and among them, a copolymer having a high molecular weight structure has a strong surface elasticity effect and a surface viscosity effect, and is effective. Among these foam stabilizers, a water-soluble polyether siloxane is effective for a polyether foam, and a polysiloxane / polyoxyalkylene copolymer is effective for a polyester foam. The foam stabilizer is not limited to these. The amount of the foam stabilizer is appropriately determined according to the type and the like.

In the present invention, inorganic additives are expected to have effects of increasing the strength of the polyurethane foam and / or the polyisocyanurate foam, improving the thermal stability and decreasing the thermal expansion coefficient as other additives. A filler, an organic filler, and the like are used.

In the present invention, the solution containing the organic polyisocyanate and the solution obtained by mixing and adjusting the catalyst and the like in a polyol are placed in separate containers, and using a special injector, under conditions of high temperature and high pressure, for example, 70 ° C. As described above, contact mixing is performed in the water-discharging layer region under the condition of 20 kgf / cm ² (about 19.4 atmospheric pressure) to 60 kgf / cm ² (about 58.2 atmospheric pressure). As a result, a foaming reaction occurs, and the water escape layer is closed by the obtained polyurethane foam and / or polyisocyanurate foam.

e. Examples Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited thereto.

In the following Examples 1-3, a polyisocyanate containing an NCO group and a polyol component in which a catalyst, a foaming agent and other auxiliaries are mixed in advance with respect to a formation in which water was lost during excavation. Using a special filling machine filled in separate containers, mix quickly through a static mixer (mixer) at the tip of the filling machine, and discharge this chemical solution from the nozzle to infiltrate the lost water layer. After that, foaming and curing were performed to close the voids in the water lost layer.

[Example-1] As a polyol component of Liquid A, a hydroxyl value obtained by addition polymerization of propylene oxide to trifunctional glycerin was 400 mg.
Liquid B was prepared by mixing 200 parts by weight of KOH / g polyether, 10 parts by weight of a foaming agent, 10 parts by weight of a foam stabilizer (water-soluble polyether siloxane), and 0.6 parts by weight of an organotin catalyst (dibutyltin diacetate). As an aliphatic polyisocyanate component, 1,3-bisisocyanatocyclohexane 228.4
Using parts by weight, these solutions are taken in independent vessels of a high-temperature and high-pressure reaction vessel capable of adjusting the temperature and pressure of Solution A and Solution B, and the inside of the reaction layer is maintained at the set environmental conditions, and the temperature and pressure are uniform. The liquid A and the liquid B were simultaneously discharged into the reaction layer at the time when the mixture became, contact-mixed, and foamed to produce a foam. At this time, the reaction state, the volume expansion ratio, and the density of the foam were measured. Table 1 shows the results.

Example 2 As a polyol component of the liquid A, a hydroxyl value obtained by addition polymerization of propylene oxide to tetrafunctional methyl glucoside was 46.
180 parts by weight of 0 mg KOH / g polyether, 12 parts by weight of a blowing agent,
10 parts by weight of a foam stabilizer (water-soluble polyether siloxane), 0.6 parts by weight of an organic tin catalyst (dibutyltin mercaptide) and 20 parts by weight of oleic acid as an organic filler are mixed and adjusted, and a liquid B is used as an aliphatic polymer. Using 235.4 parts by weight of 1,3-bisisocyanatocyclohexane, which is an isocyanate component, take these solutions in independent containers and keep the inside of the reaction layer under the set environmental conditions until the temperature and pressure become uniform. The solution A and the solution B were simultaneously discharged into the reaction layer, mixed by contact, and foamed to form a foam.
At this time, the reaction state, the volume expansion ratio, and the density of the foam were measured. Table 1 shows the results.

[Example-3] As a polyol component of the liquid A, a hydroxyl value of 400 mg KO obtained by addition polymerization of propylene oxide to trifunctional glycerin.
180 parts by weight of H / g polyether, 12 parts by weight of foaming agent, 10 parts by weight of foam stabilizer (water-soluble polyether siloxane), 0.6 parts by weight of organotin catalyst (dibutyltin mercaptide) and oleic acid as organic filler Mix and adjust 20 parts by weight,
As liquid B, 235.4 parts by weight of dicyclohexylmethane-4,4-diisocyanate which is an aliphatic polyisocyanate component was used, and these solutions were each taken in an independent container. When the pressure and the pressure became uniform, the liquid A and the liquid B were simultaneously discharged into the reaction layer, mixed by contact, and foamed to produce a foam. At this time, the reaction state, the volume expansion ratio, and the density of the foam were measured. Table 2 shows the results.

In Comparative Example 1, a commercially available polyethylene foam was used.

Density of volume expansion ratio = stock solution (Kg / m ³⁾ measured the density of the ÷ foam (Kg / m ³⁾ In Comparative Example 2, a commercially available polyethylene foam was used.

Volume expansion ratio = Density of source solution (Kg / m ³ ) ÷ Measured density of foam (Kg / m ³ ) [Example-4] Inner diameter as drainage layer model 5 of the simulated well test device shown in FIG. The following water loss prevention test was carried out using two types each having a length of 16.7 mm and 28.0 mm and a length of 1000 mm.

In FIG. 1, 1 is a container for liquid A, 2 is a container for B,
Is a mixer, 4 is a simulated well, and 5 is a lost water model.

Water loss prevention test-1 Hydroxyl value 400mg KO obtained by addition polymerization of propylene oxide to trifunctional glycerin as the polyol component of solution A
250 parts by weight of H / g polyether, 12.5 parts by weight of a foaming agent, 12.5 parts by weight of a foam stabilizer (water-soluble polyether siloxane) and 0.75 parts by weight of an organotin-based catalyst (dibutyltin mercaptide) are mixed and prepared as a liquid B. 1,3-bisisocyanatocyclohexane 2 which is an aliphatic polyisocyanate component
Using 75.8 parts by weight, these solutions were placed in independent vessels 1 and 2 of the simulated well test device shown in Fig. 1, and the simulated well 4 was maintained at the set environmental conditions, and the temperature and pressure were uniform. At that point, the solution A and the solution B were mixed in contact with the mixer 3 and mixed.
At the same time, the water was discharged into the simulated well 4 and foamed to close the lost water layer. When the hardening of the foam is completed, the part of the lost water layer model 5 is removed, the filling rate of the lost water layer model 5 by the foam is measured, and then, using the simulated well test device shown in FIG. Is released to atmospheric pressure and installed, and in the simulated well 4, 1.5% of lightweight aggregates with an average diameter of 0.4 mm and 1.0 mm, respectively
The simulated well 4 was filled with muddy water containing the muddy water, and the simulated well 4 was kept at the set environmental conditions and allowed to stand for 30 minutes. After that, mock well 4 was weighed 10kgf /
m ² (about 9.68 atmospheric pressure) pressurized to each, maximum pressure 70 kgf / m ² (about
(67.75 atmospheric pressure).

The presence or absence of a pressure drop under each pressure was measured. Table 3 shows the results.

Water loss prevention test-2 Hydroxyl value 46 obtained by addition polymerization of propylene oxide to tetrafunctional methyl glucoside as a polyol component of solution A
250 mg by weight of 0 mg KOH / g polyether, 12.5 parts by weight of a foam stabilizer (water-soluble polyether siloxane), 12.5 parts by weight of a blowing agent (dichloromonofluoromethane), and 0.75 parts by weight of an organotin-based catalyst (dibutyltin mercaptide) After mixing and adjusting, as liquid B, dicyclohexylmethane-4,4-diisocyanate 27 which is an aliphatic polyisocyanate component was used.
Using 5.5 parts by weight, these solutions were placed in independent vessels 1 and 2 of the simulated well test equipment shown in Fig. 1, and the simulated well 4 was maintained at the set environmental conditions, and the temperature and pressure were made uniform. At that point, the solution A and the solution B were mixed in contact with the mixer 3 and mixed.
Simultaneously, the water was discharged into the simulated well 4 and foamed to close the lost water layer model 5. When the hardening of the foam is completed, the part of the lost water layer model 5 is removed, the filling rate of the lost water layer model 5 by the foam is measured, and then, using the simulated well test device shown in FIG. Is released to the atmospheric pressure and installed, and lightweight aggregates with average diameters of 0.4 mm and 1.0 mm are set in the simulated well 4 respectively.
Mud water containing 1.5% was filled, the inside of the simulated well 4 was maintained at the set environmental conditions, and allowed to stand for 30 minutes. After that, mock well 4
The pressure was increased every kgf / m ² , and the pressure was increased to a maximum pressure of 70 kgf / g ² .

The presence or absence of a pressure drop under each pressure was measured. Table 3 shows the results.

Water loss prevention test-3 Hydroxyl value 400mg KO obtained by addition polymerization of propylene oxide to trifunctional glycerin as the polyol component of solution A
H / g polyether 225 parts by weight, foaming agent 15 parts by weight, foam stabilizer (water-soluble polyether siloxane) 12.5 parts by weight, organotin catalyst (dibutyltin mercaptide) 0.75 parts by weight, and olein as an organic filler 25 parts by weight of an acid were mixed and adjusted, and as a liquid B, 253.3 parts by weight of 1,3-bisisocyanatomethylcyclohexane which was an aliphatic polyisocyanate component was used. These solutions were used in the simulated well test apparatus shown in FIG. Take them in independent vessels 1 and 2 respectively, keep the inside of the simulated well 4 under the set environmental conditions, and when the temperature and pressure become uniform, mix and mix the solution A and the solution B with the mixer 3 and simultaneously simulate The water was discharged into the well 4, foamed, and the lost water layer model 5 was closed. When the setting of the foam is completed, the part of the lost water layer model 5 is removed, the filling factor of the lost water layer model 5 by the foam is measured, and then the simulated well test device shown in FIG. 1 is used. Atmospheric pressure is released and installed, and the simulated well 4 is filled with muddy water containing 1.5% each of lightweight aggregates having an average diameter of 0.4 mm and 1.0 mm, and the simulated well 4 is maintained at the set environmental conditions. Let stand for 30 minutes. After that, the simulated well 4 was changed to 10 kgf / m ²
Each time, the pressure was increased to a maximum pressure of 70 kgf / m ² .

The presence or absence of a pressure drop under each pressure was measured. Table 3 shows the results.

Comparative test for water loss prevention Muddy water containing 8% of a water loss prevention agent (walnut grain crushed material: cottonseed slag = 1: 1) conventionally used was filled in a simulated well test device shown in FIG. The inside of the simulated well 4 was kept under the set environmental conditions, and allowed to stand still for 30 minutes to block the lost water layer. Next, the model well 4 was pressurized every 10 kgf / m ² , and the maximum pressure was 70 kg.
Pressurized to f / m ² .

The presence or absence of a pressure drop under each pressure was measured. Table 3 shows the results.

Filling ratio of the aquifer layer = length of the foam molded in the aquifer layer model / length of the aquifer layer model × 100 f. Effects of the Invention The water loss prevention method of the present invention contains an organic polyisocyanate. Fill the solution and the solution containing the polyol into separate containers, using a dedicated injector equipped with these containers,
Drop this into the well and raise it to 70 kg or more and 20 kgf / cm ² (approximately 19.4
The above two types of solutions are mixed and foamed in the aquifer layer region under the conditions of high temperature and high pressure (atmospheric pressure) or higher, so it is not necessary to pay attention to the temperature and pressure conditions, The water can be prevented from escaping from the spill layer and the dedicated injector with the container can be reused.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a simulated well test device used in Example-4. 1 ... container for liquid A, 2 ... container for liquid B, 3 ... mixer, 4 ... simulated well, 5 ... lost water layer model.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-52-144111 (JP, A) JP-A-50-55502 (JP, A) JP-A-49-79008 (JP, A) 41397 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K ^7/ 00-7/02 C09K 17/30

Claims (3)

(57) [Claims] 1. A catalyst and a blowing agent are mixed with a solution containing an organic polyisocyanate having an active isocyanate group and a polyol obtained by addition polymerization of a compound having two or more active hydrogens with an alkylene oxide. Using a special injector equipped with a container separately filled with
This was lowered into a wellbore, 70 ° C. or higher, the missing water layer area in the conditions of high temperature and high pressure 20~60kgf / cm ^2, to foam in contact mixture discharged the two solutions, missing water And the resulting low-density polyurethane foam and / or
Alternatively, a method for preventing water from flowing out of a water-emitting layer under high temperature and high pressure, comprising closing the water-emitting layer by curing a polyisocyanurate foam. 2. The method according to claim 1, wherein the organic polyisocyanate having an active isocyanate group comprises an aromatic or aliphatic polyisocyanate monomer or mixture or a modified product thereof. The described water loss prevention method. 3. A polyol comprising a polyether-based or polyester-based polyol obtained by addition-polymerizing an alkylene oxide to a compound having two or more active hydrogens, such as a low-molecular-weight polyhydric alcohol or polyamine. The method for preventing water loss according to claim (1).