CN105885812A - Well cementation working solution system and preparing method thereof - Google Patents

Abstract

The invention relates a well cementation working solution system and a preparing method thereof. The working solution system is mainly prepared by combining a base solution part and a dry ash part at the mass ratio of 1:(1.4-2.5). The base solution part is prepared from, by weight, 100 parts of water, 0.3-3.5 parts of a stabilizing agent, 1.5-5 parts of a suspending agent, 0-10 parts of a parting agent, 2-12 parts of an activating agent, 0-5 parts of a thickening time control agent and 0-4 parts of a thinning agent. The dry ash part is prepared from, by weight, 30-120 parts of a curing agent and 0-250 parts of a weighting agent. The preparing method comprises the following steps that firstly, the base solution part and the dry ash part are prepared according to the formula dosages respectively; secondly, the base solution part and the dry ash part prepared in the first step are mixed according to the formula dosages according to the construction requirement, and the working solution system is obtained, wherein the density of the working solution system ranges from 1.2 g/cm<3> to 2.8 g/cm<3>, and the suitable environment temperature ranges from 0 DEG C to 180 DEG C.

Description

A cementing working fluid system and its preparation method

technical field

The invention relates to a cementing working fluid system, specifically, a cementing working fluid system and a preparation method of the working fluid system.

Background technique

Cementing is the operation process of injecting cement slurry into the annular space formed by the casing and the formation to form a cement sheath after drilling and before completion. The purpose is to fix the casing, support the formation, and seal off water, oil and gas layers. After cementing, the cement sheath, drilling fluid mud cake and formation constitute the second interface in the annular space. The physical and chemical properties of these three materials are different, and the homogeneous integrated cementation cannot be realized, which induces the failure of the annulus seal, which is an important reason affecting the cementing quality. Especially in the deviated section, the cementing operation is more complicated and more difficult due to the frequent changes of the inclination angle and azimuth angle, and the uneven change rate of the borehole diameter due to the different formation lithology.

The failure of sealing the cementing interface is mainly due to the loose mud cake at the interface between the cement sheath and the formation, which blocks the direct contact and cementation between the cement slurry and the formation, and the mud cake becomes brittle after dehydration and drying. Different degrees of peeling occur between the annulus and the rock wall of the formation, resulting in the formation of micro-cracks, resulting in a decrease in the bonding strength of the cementing interface, providing channeling channels for the fluid trapped in the formation, and reducing the durability of the cement sheath.

At present, there are two technologies to solve the adverse effect of drilling fluid mud cake on cementing quality: drilling fluid mud cake removal technology and drilling fluid mud cake solidification technology:

Among them, drilling fluid mud cake removal technology includes three types of physical, chemical and biological removal, but the removal of drilling fluid mud cake is not conducive to the stability of the wellbore wall, and physical removal is likely to cause changes in borehole diameter and affect the quality of subsequent operations. Cause secondary erosion and corrosion damage to the casing;

Drilling fluid mud cake solidification technologies mainly include MTC (Mud to Cement) and MTA (Mud to Agglomerated Cake) technologies. MTC technology is to add solidification components to the drilling fluid to make the drilling fluid, including its mud cake, capable of solidification. MTA technology is Add mud cake modifier to the drilling fluid to assist its mud cake solidification and cementation. However, these methods may need to change the drilling fluid composition, or need to add specific technological measures, and the adaptability to the drilling fluid type is poor. In addition, the effects of the above technologies will all be affected by the subsequent working fluid system (isolating fluid, flushing fluid) and will be reduced.

To sum up, to improve the cementing quality, especially the cementing quality of the deviated section, it is not appropriate to modify the mud cake from the drilling fluid, but the working fluid before cementing should be used as the research object of the mud cake solidification technology. scientifically sound.

Contents of the invention

The purpose of the present invention is to: aim at the deficiencies of the above-mentioned prior art, provide a kind of cementing working fluid system that uses the working fluid before cementing as the mud cake solidification technology to improve the cementing quality, especially the cementing quality of the inclined well section, And the preparation method of the working fluid system.

The objective technical solution of the present invention is: a cementing working fluid system, the working fluid system is mainly composed of a base fluid part and a dry ash part, and the raw material ratio of the base fluid part is calculated according to the following parts by weight:

The raw material ratio of described dry ash part is calculated by following weight parts:

Curing agent 30～120 parts,

Weighting agent 0～250 parts;

The combination ratio of the base liquid part and the dry ash part is calculated according to the following mass ratio: 1:1.4-2.5.

Described stabilizer mainly is made up of following mass percent raw material:

Bentonite 70～100%,

Vermiculite 0-30%.

Described suspending agent mainly is made up of following mass percent raw material:

Described release agent mainly is made up of following mass percent raw material:

Described activator is mainly made up of following mass percent raw material:

The coagulation regulator is mainly composed of the following mass percentage raw materials:

The curing agent is an artificial geopolymer mainly composed of the following raw materials in mass percentage:

The weighting agent is mainly composed of barite, ilmenite powder, manganese iron powder and/or manganese powder.

The preparation method of the above-mentioned cementing working fluid system comprises the following steps:

Step 1). Configure the base liquid part and the dry ash part respectively according to the formula quantity;

Step 2). According to the construction requirements, configure the base liquid part and dry ash part prepared in step 1) according to the formula quantity to obtain the working fluid system. The density of the working fluid system is 1.2-2.8g/cm ³ , which is suitable for The ambient temperature is 0~180℃.

The beneficial effects of the present invention are:

1. The present invention has actively adjustable rheological properties. While not affecting other properties, it can be artificially and actively regulated according to the rheological properties of drilling fluid and cement slurry, so as to make it in the optimal state of replacement performance and meet the flow requirements. To meet the requirements of variable grade difference, the turbulent flow of drilling fluid can be efficiently displaced; at the same time, the invention can destroy the surface structure of drilling fluid mud cake, and replace the original drilling fluid mud without curing characteristics through the penetration and exchange mechanism of curing agent and activator Cake, forming a new curable layer on the surface of the interface, so as to achieve the improvement of interface bonding performance;

2. The present invention is used between drilling fluid and cement slurry, and has no special requirements on operating conditions and process design, ensuring that the cementing operation process is carried out continuously; moreover, the present invention has excellent advantages with drilling fluid and cement slurry. Chemical compatibility, which can fully isolate the direct contact between drilling fluid and cement slurry, avoid chemical pollution, ensure the safety of cementing and injection operations, and improve the cementing quality of the annulus cement sheath;

3. In addition to meeting the requirements for the use of water-based drilling fluids, the present invention also has high-efficiency cleaning capabilities for oil-containing or oil-based drilling fluids, and achieves wetting reversal through surface modification of oil-containing or oil-based drilling fluids, thereby effectively cleaning The oily drilling fluid remaining on the surface of the casing and well wall optimizes the cementation environment at the interface of the cementing annulus and helps improve the quality of wellbore preparation before cementing.

detailed description

The invention relates to a well cementing working fluid system for improving the cementing quality, especially the cementing quality of a deviated well section. The working fluid system is mainly composed of a base fluid part and a dry ash part according to a mass ratio of 1:1.4-2.5. The content of the present invention is further described in the form of a list in conjunction with a plurality of embodiments, and the overall formula of the present invention is shown in Table 1.

Table 1 Raw material components and content ratio results of six preferred embodiments of the present invention

In each of the examples shown in Table 1 above, the raw material ratio of the stabilizer in the base liquid part is shown in Table 2.

Table 2 The results of the ratio of stabilizer raw materials in the base liquid part

In each of the examples shown in Table 1 above, the raw material proportions of the suspending agent in the base liquid part are shown in Table 3.

Table 3 Proportion results of suspending agent raw materials in the base liquid part

In each of the embodiments shown in Table 1 above, the raw material ratio of the release agent in the base liquid part is shown in Table 4.

Table 4 Raw material ratio results of release agent in base fluid

In each of the examples shown in Table 1 above, the raw material ratio of the activator in the base liquid part is shown in Table 5.

Table 5 Ratio results of activator raw materials in the base liquid part

In each of the examples shown in the above Table 1, the raw material ratio of the coagulant regulator in the base liquid part is shown in Table 6.

Table 6 Ratio results of coagulation regulator raw materials in the base liquid part

In each of the examples shown in Table 1 above, the diluent in the base liquid is sulfonated tannin.

In each embodiment shown in the above table 1, the curing agent of the dry ash part is an artificial geopolymer, and its raw material ratio is shown in table 7.

Table 7 The results of the ratio of curing agent raw materials in the dry ash part

In each embodiment shown in the above Table 1, the weighting agent of the dry ash part is barite, ilmenite powder, manganese iron ore powder or manganese ore powder, or a mixture of two or more of them.

The preparation method of the cementing working fluid system of each of the above-mentioned embodiments comprises the following steps:

Step 1). Configure the base liquid part and the dry ash part respectively according to the formula quantity;

Step 2). According to the construction requirements, the base liquid part and the dry ash part configured in step 1) are configured according to the formula quantity to obtain a working fluid system. The density of the working fluid system ranges from 1.2 to 2.8 g/ Its suitable ambient temperature between cm ³ is 0～180℃.

The technical solutions of the above embodiments are only used to illustrate the present invention, not to limit it. Although the present invention has been described in detail with reference to the technical solutions of the aforementioned embodiments, those skilled in the art should understand that: they can still modify the aforementioned technical solutions, or perform equivalent replacements to some of the technical features; and these modifications or Substitution does not make the essence of the corresponding technical solution deviate from the spirit and scope of the present invention.

Claims (9)

1. A cementing working fluid system, the working fluid system is mainly composed of a base fluid part and a dry ash part, it is characterized in that, the raw material ratio of the base fluid part is calculated by the following parts by weight: 100 parts of water, Stabilizer 0.3～3.5 parts, Suspending agent 1.5~5 parts, Partition agent 0～10 parts, Activator 2 to 12 parts, Coagulant regulator 0-5 parts, Thinner 0~4 parts; The raw material ratio of described dry ash part is calculated by following weight parts: Curing agent 30～120 parts, Weighting agent 0～250 parts; The combination ratio of the base liquid part and the dry ash part is calculated according to the following mass ratio: 1:1.4-2.5. 2. according to the described cementing working fluid system of claim 1, it is characterized in that, described stabilizer is mainly made up of following mass percentage raw material: Bentonite 70～100%, Vermiculite 0-30%. 3. according to the described cementing working fluid system of claim 1, it is characterized in that, described suspending agent mainly is made up of following mass percentage raw material: Sodium carboxymethyl cellulose 3~8%, Sodium ethyl cellulose 3～10%, Polyvinyl alcohol 0~5%, Sodium polyacrylate 0～5%, Xanthan gum 0～10%, Acrylic copolymer 15-35%, Alkyl phthalate amide 5-25%, Sodium bentonite 5-20%, Metakaolinite 0~10%. 4. The cementing working fluid system according to claim 1, wherein the release agent is mainly composed of the following mass percentage raw materials: Sodium bentonite 20-40%, Sodium carboxymethyl cellulose 15-25%, Sodium hydroxyethyl cellulose 20-35%, Cellulose 15-35%. 5. The cementing working fluid system according to claim 1, wherein the activator is mainly composed of the following mass percentage raw materials: Sodium hydroxide 20-50%, Sodium bicarbonate 0～15%, Sodium carbonate 30～60%, Sodium silicate 20-50%. 6. The cementing working fluid system according to claim 1, wherein the coagulation regulator is mainly composed of the following mass percentage raw materials: Sodium tripolyphosphate 0～15%, Potassium Sodium Tartrate 0～75%, Sodium citrate 0～25%, Sodium salicylate 0～20%, Sodium gluconate 0-75%. 7. The cementing working fluid system according to claim 1, wherein the curing agent is an artificial geopolymer mainly composed of the following raw materials in mass percentage: Calcium oxide 20-50%, Silicon oxide 15-40%, Aluminum oxide 10-40%, Magnesium oxide 15-40%, Zinc oxide 5-20%, Titanium oxide 0~5%. 8. The cementing working fluid system according to claim 1, wherein the weighting agent is mainly composed of barite, ilmenite powder, manganese iron powder and/or manganese powder. 9. A preparation method of the cementing working fluid system according to claim 1, comprising the following steps: Step 1). Configure the base liquid part and the dry ash part respectively according to the formula quantity; Step 2). According to the construction requirements, configure the base liquid part and dry ash part prepared in step 1) according to the formula quantity to obtain the working fluid system. The density of the working fluid system is 1.2-2.8g/cm ³ , which is suitable for The ambient temperature is 0~180℃.