Foam permeable cement for hydrate sand control and preparation method thereof

Abstract

The invention discloses foam permeable cement for hydrate sand control and a preparation method of the foam permeable cement. The foam permeable cement comprises the following components in parts by weight: 100 parts of oil well cement, 50-100 parts of a large-particle material, 15-40 parts of a water-soluble material, 0.1-10 parts of a communicating agent, 50-100 parts of water and 15-30 parts of a foaming material. Wherein the size of the large particle material is 20-80 meshes. The foam permeable cement disclosed by the invention can adapt to a low-temperature hydrate reservoir, has a sand prevention effect, and can effectively prevent the phenomena of well wall instability and serious sand production caused by the change of the mechanical property of a hydrate-containing stratum in the exploitation process. The thickening time of the foam permeable cement can meet the safety construction requirement at the temperature of 30 DEG C, the strength development can reach 5 MPa or above at the temperature of 10 DEG C, meanwhile, the permeability reaches 200 mD, and the on-site sand control requirement is met.

Description

Technical Field

[0001] The present application relates to the field of cementing operations, and in particular to a foam permeable cement for hydrate sand control and a preparation method thereof. Background Art

[0002] Natural gas hydrate is considered to be one of the most promising new clean energy sources to replace coal, oil and natural gas in the 21st century. Its total resource volume is approximately twice the total carbon content of traditional fossil fuels that have been proven worldwide. Due to its huge reserves, high efficiency, cleanness and high calorific value, countries are constantly competing to research and develop it.

[0003] Cementing operations during hydrate mining are a prerequisite and important guarantee for the effective exploration and development of hydrate resources. However, the terrain conditions for hydrate cementing operations in offshore areas are complex. Affected by the low natural permeability of the reservoir, shallow burial, weak cementation, high mud content, and small sand particle size, the natural production of the test wells is low. Foreign hydrate test production experience shows that sand production is one of the main reasons for the forced suspension of hydrate test production, which seriously limits the operating time of natural gas hydrate test production and affects operational safety.

[0004] At present, sand control focuses on the research and application of mechanical sand control methods, but there is a lack of research on chemical sand control materials and methods. Chemical sand control can use resin or other sand consolidating agents to cement the gravel in the formation or the sand and stone filled into the formation, stabilize the formation structure or form an artificial well wall with a certain strength and permeability, thereby preventing sand from coming out of the formation. The main chemical sand control materials used in China are phenolic resin, urea-formaldehyde resin and silicone-resin. However, there is a lack of research on the porous cementitious material sand consolidation system based on the geological characteristics of the hydrate reservoir. The existing sand control system is only suitable for relatively high temperatures. The temperature of the hydrate reservoir is 10-15°C, and the existing system is not applicable under the hydrate reservoir.

[0005] Therefore, it is urgently necessary to develop a cement slurry suitable for preventing sand penetration in hydrate formations in combination with cementing technology. Summary of the invention

[0006] The present application provides a foam permeable cement for hydrate sand control and a preparation method thereof, which can solve the problem of sand production in hydrate formations.

[0007] This application adopts the following technical solutions:

[0008] The present application provides a foam permeable cement for hydrate sand control, comprising the following components: 100 parts by weight of oil well cement, 50-100 parts by weight of large particle material, 15-40 parts by weight of water-soluble material, 0.1-10 parts by weight of connecting agent, 50-100 parts by weight of water, and 15-30 parts by weight of foaming material, wherein the large particle material has a mesh size of 20-80.

[0009] Furthermore, the large particle material includes one or a combination of ceramsite, quartz sand, and perlite particles.

[0010] Furthermore, the water-soluble material includes one or a combination of sodium chloride, water-soluble silicone oil, and ethylene glycol.

[0011] Furthermore, the connecting agent includes polyester fiber and / or hemp fiber.

[0012] Furthermore, the foaming material comprises the following components: 5 to 13 parts by weight of a gas generating agent FCA, 5 to 13 parts by weight of a gas generating agent FCB, and 3 to 5 parts by weight of a foam stabilizer.

[0013] Further, the foamed permeable cement comprises the following components: 100 parts by weight of oil well cement, 100 parts by weight of large particle material, 20 parts by weight of water-soluble material, 1 part by weight of connecting agent, 100 parts by weight of water, and 30 parts by weight of foaming material. Among them, the large particle material is 40 meshes. The foaming material comprises the following components: 13 parts by weight of gas generating agent FCA, 12 parts by weight of gas generating agent FCB, and 5 parts by weight of foam stabilizer.

[0014] The embodiments of the present application also provide a method for preparing the above-mentioned foamed permeable cement for hydrate sand control, comprising the following steps: mixing oil well cement, large particle material, a connecting agent, a water-soluble material, water and a foaming material to form foamed permeable cement.

[0015] Furthermore, the preparation method comprises the following steps: mixing oil well cement, large particle material, and gas generating agent FCA to form a dry mix; mixing a connecting agent, a water-soluble material, a gas generating agent FCB, a foam stabilizer, and water to form a mixed liquid; and mixing the dry mix and the mixed liquid to form foam permeable cement.

[0016] Compared with the prior art, this application has the following beneficial effects:

[0017] 1. The foam permeable cement of the present application can adapt to low-temperature hydrate reservoirs and has a sand control effect, which can effectively prevent the phenomenon of well wall instability and severe sand production caused by changes in the mechanical properties of hydrate-containing formations during mining.

[0018] 2. The thickening time of the foamed permeable cement of the present application can meet the safety construction requirements at 30°C, and the strength development can reach more than 5MPa at 10°C. At the same time, the permeability reaches 200mD, which meets the on-site sand control requirements. DETAILED DESCRIPTION

[0019] The technical methods in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0020] The main reason for sand production is that the hydrate reservoir, especially the hydrate in the sea area, is shallowly buried, and the sediment skeleton is mainly weakly consolidated and unconsolidated sandy and silty sediments with a high mud content. During the exploitation process, the hydrate phase change will cause the mechanical properties and porosity of the reservoir to change, and the in-situ formation stress will also be redistributed, which is easy to induce a series of geological risk problems such as well wall instability, wellbore sanding, formation settlement and submarine landslides. Among them, sand production is one of the bottleneck problems restricting the safe and efficient exploitation of hydrates. Sand production will increase the amount of sand in the wellbore, causing damage to underground equipment such as electric submersible pumps or even shutdown; and sand production will also cause damage to the formation structure around the well and reduce its strength, redistribute the ground stress, and increase the risk of geological disasters.

[0021] In response to the above-mentioned sand production problem in hydrate formations, an embodiment of the present application provides a foam permeable cement for hydrate sand control, comprising the following components: 100 parts by weight of oil well cement, 50 to 100 parts by weight of large particle material, 15 to 40 parts by weight of water-soluble material, 0.1 to 10 parts by weight of a connecting agent, 50 to 100 parts by weight of water, and 15-30 parts by weight of a foaming material.

[0022] Among them, the large particle material is 20-80 mesh, that is, the large particle material can be 20 mesh, 50 mesh, 80 mesh, etc. The large particle material can be one or a combination of ceramsite, quartz sand, and perlite particles, that is, the large particle material can be ceramsite, a mixture of ceramsite and quartz sand, or a mixture of quartz sand and perlite particles. The amount of the large particle material can be 50 parts by weight, 80 parts by weight, 100 parts by weight, etc. The above-mentioned large particle material can increase the interface transition zone and form a seepage channel.

[0023] The water-soluble material can be one of sodium chloride, water-soluble silicone oil, and ethylene glycol, or a combination of several of them, that is, the water-soluble material can be sodium chloride, or a mixture of sodium chloride and water-soluble silicone oil, or a mixture of water-soluble silicone oil and ethylene glycol, etc. The amount of the water-soluble material can be 15 parts by weight, 30 parts by weight, 40 parts by weight, etc. The above-mentioned water-soluble material does not react with cement, and can seep out through treatment in the later stage to increase the permeability of cement stone.

[0024] The connecting agent can be polyester fiber and / or hemp fiber, that is, the connecting agent can be polyester fiber, hemp fiber, or a mixture of polyester fiber and hemp fiber. The amount of the connecting agent can be 0.1 parts by weight, 1 part by weight, 10 parts by weight, etc. The connecting agent can connect the pores in the foam cement.

[0025] The foaming material may include the following components: 5 to 13 parts by weight of a gas generating agent FCA, 5 to 13 parts by weight of a gas generating agent FCB, and 3 to 5 parts by weight of a foam stabilizer.

[0026] The amount of the gas generating agent FCA can be 5 parts by weight, 8 parts by weight, 13 parts by weight, etc.

[0027] The amount of the gas generating agent FCB can be 5 parts by weight, 8 parts by weight, 13 parts by weight, etc.

[0028] The amount of the foam stabilizer can be 3 parts by weight, 4 parts by weight, 5 parts by weight, etc. The foam stabilizer can be specifically a foam stabilizer FCF.

[0029] For example, the foamed permeable cement includes the following components: 100 parts by weight of oil well cement, 100 parts by weight of large particle material, 20 parts by weight of water-soluble material, 1 part by weight of connecting agent, 100 parts by weight of water, and 30 parts by weight of foaming material. Among them, the large particle material is 40 mesh. The foaming material includes the following components: 13 parts by weight of gas generating agent FCA, 12 parts by weight of gas generating agent FCB, and 5 parts by weight of foam stabilizer.

[0030] The embodiment of the present application provides a method for preparing the above-mentioned foam permeable cement for hydrate sand control, comprising the following steps:

[0031] The foamed permeable cement is formed by mixing oil well cement, large particle material, connecting agent, water-soluble material, water and foaming material.

[0032] Specifically, the preparation method comprises the following steps:

[0033] (1) The oil well cement, the large particle material and the gas generating agent FCA are mixed evenly to form a dry mix.

[0034] (2) The connecting agent, the water-soluble material, the gas generating agent FCB, the foam stabilizer and water are mixed uniformly to form a mixed liquid.

[0035] (3) The dry mix and the mixing liquid are mixed evenly to form foamed permeable cement.

[0036] The cement slurry solidifies quickly under the conditions of hydrate formations to form oil and gas channels with certain permeability and high strength, which can effectively improve the sand production problem of hydrate formations. The oil and gas channels formed after the cement slurry system solidifies under the conditions of hydrate formations have high permeability and low-temperature strength, stable chemical properties, and can effectively improve the sand production problem of hydrate formations and meet the requirements of on-site engineering.

[0037] The following is a detailed description with reference to specific embodiments:

[0038] In the following embodiments, the water-soluble material is water-soluble silicone oil and the connecting agent is polyester fiber.

[0039] Example 1

[0040] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0041] 100 parts by weight of oil well cement, 60 parts by weight of 20 mesh quartz sand, 35 parts by weight of water-soluble material, 0.1 parts by weight of connecting agent, 60 parts by weight of water, and 15 parts by weight of foaming material. The foaming material is composed of: 6 parts by weight of gas generating agent FCA, 6 parts by weight of gas generating agent FCB, and 4 parts by weight of foam stabilizer.

[0042] The preparation process is:

[0043] 100 parts by weight of oil well cement, 60 parts by weight of 20 mesh quartz sand and 6 parts by weight of gas generating agent FCA are mixed into a dry mix. 5 parts by weight of water-soluble material, 0.1 parts by weight of connecting agent, 60 parts by weight of water, 6 parts by weight of gas generating agent FCB and 4 parts by weight of foam stabilizer are mixed into a mixed liquid. Then the dry mix and the mixed liquid are mixed into cement slurry, i.e., foam permeable cement.

[0044] Example 2

[0045] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0046] 100 parts by weight of oil well cement, 80 parts by weight of 40 mesh quartz sand, 15 parts by weight of water-soluble material, 0.3 parts by weight of connecting agent, 80 parts by weight of water, and 20 parts by weight of foaming material. The foaming material is composed of: 8 parts by weight of gas generating agent FCA, 8 parts by weight of gas generating agent FCB, and 4 parts by weight of foam stabilizer.

[0047] The preparation process is:

[0048] 100 parts by weight of oil well cement, 80 parts by weight of 40 mesh quartz sand and 8 parts by weight of gas generating agent FCA are mixed into a dry mix. 15 parts by weight of water-soluble material, 0.3 parts by weight of connecting agent, 80 parts by weight of water, 8 parts by weight of gas generating agent FCB and 4 parts by weight of foam stabilizer are mixed into a mixed liquid. Then the dry mix and the mixed liquid are mixed into cement slurry, i.e., foam permeable cement.

[0049] Example 3

[0050] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0051] 100 parts by weight of oil well cement, 100 parts by weight of 40 mesh quartz sand, 20 parts by weight of water-soluble material, 1 part by weight of connecting agent, 100 parts by weight of water, and 30 parts by weight of foaming material. The foaming material is composed of: 13 parts by weight of gas generating agent FCA, 12 parts by weight of gas generating agent FCB, and 5 parts by weight of foam stabilizer.

[0052] The preparation process is:

[0053] 100 parts by weight of oil well cement, 100 parts by weight of 40 mesh quartz sand and 13 parts by weight of gas generating agent FCA are mixed into a dry mix. 20 parts by weight of water-soluble material, 1 part by weight of connecting agent, 100 parts by weight of water, 12 parts by weight of gas generating agent FCB and 5 parts by weight of foam stabilizer are mixed into a mixed liquid. Then the dry mix and the mixed liquid are mixed into cement slurry, i.e., foam permeable cement.

[0054] Example 4

[0055] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0056] 100 parts by weight of oil well cement, 100 parts by weight of 80 mesh quartz sand, 30 parts by weight of water-soluble material, 0.8 parts by weight of connecting agent, 85 parts by weight of water, and 25 parts by weight of foaming material. The foaming material is composed of: 10 parts by weight of gas generating agent FCA, 10 parts by weight of gas generating agent FCB, and 5 parts by weight of foam stabilizer.

[0057] The preparation process is:

[0058] 100 parts by weight of oil well cement, 100 parts by weight of 80 mesh quartz sand and 10 parts by weight of gas generating agent FCA are mixed into a dry mix. 30 parts by weight of water-soluble material, 0.8 parts by weight of connecting agent, 85 parts by weight of water, 10 parts by weight of gas generating agent FCB and 5 parts by weight of foam stabilizer are mixed into a mixed liquid. Then the dry mix and the mixed liquid are mixed into cement slurry, i.e., foam permeable cement.

[0059] Example 5

[0060] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0061] 100 parts by weight of oil well cement, 70 parts by weight of 60 mesh quartz sand, 25 parts by weight of water-soluble material, 0.3 parts by weight of connecting agent, 75 parts by weight of water, and 20 parts by weight of foaming material. The foaming material is composed of: 8 parts by weight of gas generating agent FCA, 8 parts by weight of gas generating agent FCB, and 4 parts by weight of foam stabilizer.

[0062] The preparation process is:

[0063] 100 parts by weight of oil well cement, 70 parts by weight of 60 mesh quartz sand and 8 parts by weight of gas generating agent FCA are mixed into a dry mix. 25 parts by weight of water-soluble material, 0.3 parts by weight of connecting agent, 75 parts by weight of water, 8 parts by weight of gas generating agent FCB and 4 parts by weight of foam stabilizer are mixed into a mixed liquid. Then the dry mix and the mixed liquid are mixed into cement slurry, i.e., foam permeable cement.

[0064] Comparative Example 1

[0065] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0066] 100 parts by weight of oil well cement, 25 parts by weight of water-soluble material, 75 parts by weight of water, and 20 parts by weight of foaming material, wherein the foaming material comprises: 8 parts by weight of gas generating agent FCA, 8 parts by weight of gas generating agent FCB, and 4 parts by weight of foam stabilizer.

[0067] The preparation process is:

[0068] 100 parts by weight of oil well cement and 8 parts by weight of gas generating agent FCA are mixed into a dry mix. 25 parts by weight of water-soluble material, 75 parts by weight of water, 8 parts by weight of gas generating agent FCB and 4 parts by weight of foam stabilizer are mixed into a mixed liquid. Then the dry mix and the mixed liquid are mixed into cement slurry.

[0069] Comparative Example 2

[0070] The foam penetration cement slurry formula provided in this embodiment is composed of:

[0071] 100 parts by weight of oil well cement, 70 parts by weight of 60-mesh quartz sand, 25 parts by weight of water-soluble material, 0.3 parts by weight of connecting agent, and 75 parts by weight of water.

[0072] The preparation process is:

[0073] 100 parts by weight of oil well cement and 70 parts by weight of 60 mesh quartz sand are mixed to form a dry mix. 25 parts by weight of water-soluble material, 0.3 parts by weight of connecting agent and 75 parts by weight of water are mixed to form a mixed liquid. Then the dry mix and the mixed liquid are mixed to form cement slurry. The oil well cement is a G-grade high sulfur-resistant oil well cement that complies with GB / T 10238.

[0074] The performance of the cement slurry with the above formulation was tested according to GB / T 19139-2003, and the results are shown in Table 1.

[0075] Table 1 Cement slurry permeability evaluation test results

[0076] Serial number Coagulation time, min 48h compressive strength, MPa <![CDATA[Gas permeability, 10 -3 μm 2 > <![CDATA[Water permeability, 10 -3 μm 2 > Example 1 545 7.6 20.35 1.25 Example 2 566 6.8 43.63 2.23 Example 3 487 5.6 200.33 23.53 Example 4 602 5.9 103.35 17.65 Example 5 505 6.8 17.66 1.25 Comparative Example 1 542 6.5 1.23 0.03 Comparative Example 3 616 8.1 0.11 0.02

[0077] Table 1 shows that foam permeable cement has a high permeability, which can form oil and gas seepage channels and control sand production, thereby improving the production life and economic benefits of hydrate wells.

[0078] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present application. Without departing from the spirit and scope of the present application, the present application may have various changes and improvements, and the scope of protection required by the present application is defined by the attached claims, description and their equivalents.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present application.

Claims

1. A foam permeable cement for hydrate sand control, characterized in that: Includes the following components: 100 parts by weight of oil well cement, 50-100 parts by weight of large particle material, 15-40 parts by weight of water-soluble material, 0.1-10 parts by weight of connecting agent, 50-100 parts by weight of water, and 15-30 parts by weight of foaming material; Wherein, the large particle material is 20-80 mesh.

2. The foam permeable cement for hydrate sand control according to claim 1, characterized in that: The large particle material includes one or a combination of ceramsite, quartz sand and perlite particles.

3. The foam permeable cement for hydrate sand control according to claim 1, characterized in that: The water-soluble material includes one or a combination of sodium chloride, water-soluble silicone oil, and ethylene glycol.

4. The foam permeable cement for hydrate sand control according to claim 1, characterized in that: The connecting agent comprises polyester fiber and / or hemp fiber.

5. The foam permeable cement for hydrate sand control according to claim 1, characterized in that: The foaming material comprises the following components: 5 to 13 parts by weight of gas generating agent FCA, 5 to 13 parts by weight of gas generating agent FCB, and 3 to 5 parts by weight of foam stabilizer.

6. The foam permeable cement for hydrate sand control according to claim 1, characterized in that: The foam permeable cement comprises the following components: 100 parts by weight of oil well cement, 100 parts by weight of large particle material, 20 parts by weight of water-soluble material, 1 part by weight of connecting agent, 100 parts by weight of water, and 30 parts by weight of foaming material; wherein the large particle material is 40 mesh; The foaming material comprises the following components: 13 parts by weight of a foaming agent FCA, 12 parts by weight of a foaming agent FCB, and 5 parts by weight of a foam stabilizer.

7. A method for preparing the foam permeable cement for hydrate sand control according to any one of claims 1 to 6, characterized in that: The following steps are involved: The foamed permeable cement is formed by mixing oil well cement, large particle material, connecting agent, water-soluble material, water and foaming material.

8. The preparation method according to claim 7, characterized in that: The following steps are involved: The oil well cement, the large particle material and the gas generating agent FCA are mixed to form a dry mix; Mixing the connecting agent, the water-soluble material, the gas generating agent FCB, the foam stabilizer and the water to form a mixed liquid; The dry mix and the mixing liquid are mixed to form foamed permeable cement.