A method of using a consolidated proppant for temporary plugging of a hollow whipstock for high temperature wells

Abstract

The application discloses a method for temporarily plugging of a consolidated proppant in a high-temperature well hollow whipstock, which comprises the following steps: (i) determining the amount of the consolidated proppant to be used and weighing the consolidated proppant; (ii) plugging the bottom of a hollow position of the hollow whipstock; (iii) filling the consolidated proppant into the hollow position of the hollow whipstock, and compacting and scraping the top; (iv) wrapping a heating jacket outside the hollow position of the hollow whipstock, and heating to completely solidify the consolidated proppant. The temporary plugging method can realize that the consolidated body has good permeability at different times, the compressive strength gradually decreases with the increase of the heating time in the stratum environment, the temporary plugging and deblocking of the consolidated proppant in the hollow whipstock under the high-temperature state are realized, and the problem of insufficient temperature resistance of the traditional self-degradation temporary plugging material is solved.

Description

Technical Field

[0001] This invention belongs to the field of petroleum extraction, specifically relating to a method for temporarily plugging hollow deflectors in high-temperature wells using consolidated proppant. Background Technology

[0002] The directional drilling tool is one of the necessary tools for sidetracking multi-branch wells and sidetracking with casing opening in old wells. However, after using conventional directional drilling tools, the old wells often cannot be preserved because they cannot be retrieved or are difficult to retrieve. Especially for multi-branch wells, using conventional directional drilling tools means that the branch wells are blocked by the directional drilling tools, making it impossible to simultaneously exploit the main well and the branch wells, and thus impossible to maximize the production capacity of a single well.

[0003] Hollow directional drilling rigs or salvageable directional drilling rigs can enable simultaneous production in the main wellbore and branch wells after well completion. However, the salvage process for salvageable directional drilling rigs is complex and the operation cycle is long. Especially for the development of offshore oil fields, the daily cost of drilling operations is high, and salvage of directional drilling rigs will inevitably increase the number of procedures and extend the operation cycle, thus limiting the economic value.

[0004] There are generally two methods for plugging hollow directional ducts: plugging (directional perforation) and temporary plugging (natural unblocking). However, opening the directional duct channel of a hollow directional duct requires drilling a new side-drilled well, then using directional perforation to penetrate the inclined surface of the directional duct tool to connect the branch well and the main well. This method of opening the directional duct also has limitations such as complex technology and high operating costs.

[0005] Hollow directional drilling rigs capable of temporary plugging are a hot topic in their development. The temporary plugging materials for these rigs primarily utilize soluble metals or polymers, both of which can be used in low- to medium-temperature reservoirs. However, both materials have limited temperature resistance. When the applicable temperature of the directional drilling rig exceeds 150℃, the temporary plugging layer formed by these materials quickly fails, failing to provide effective plugging and thus preventing the completion of branch well drilling operations. Therefore, it is necessary to research a temporary plugging method for hollow directional drilling rigs with a temperature resistance exceeding 150℃. Summary of the Invention

[0006] This invention provides a method for temporarily plugging hollow inclined planes with a consolidated proppant. It overcomes the shortcomings of earlier methods using soluble metals or polymers for temporary plugging of hollow inclined planes, which resulted in insufficient temperature resistance. This method significantly improves the temperature resistance of hollow inclined planes, making them particularly suitable for operating environments with temperatures above 150°C.

[0007] This invention is achieved through the following technical solution:

[0008] A method for temporarily plugging a hollow directional probe in a high-temperature well with a consolidated proppant includes the following steps:

[0009] (i) Determine the required mass of the solidification proppant based on the volume of the area to be temporarily plugged in the hollow inclined plane and the bulk density of the solidification proppant. The calculation formula is as follows: (1)

[0010] m=ρ×V×α (1)

[0011] In equation (1): m is the mass of the consolidated proppant in g; ρ is the bulk density of the consolidated proppant in g / cm³. 3 α is an additional coefficient, with a value ranging from 1.1 to 1.3;

[0012] (ii) Weigh the consolidated propped material according to the mass of the consolidated propped material calculated in step (i);

[0013] (iii) Seal the bottom of the hollow part of the hollow inclined plate with a soft rubber plug to prevent the solidification proppant from falling out of the bottom after being installed in the hollow part;

[0014] (iv) After mixing the solidifying support and liquid curing agent in step (ii) at a volume ratio of 1:(0.8-1.5), fill the hollow position of the hollow inclined plane and use a scraper to compact and level the top.

[0015] (v) Wrap a heating jacket around the hollow part of the hollow inclined plane. The heating range of the heating jacket should at least cover the hollow part of the hollow inclined plane. Heat the hollow inclined plane for 48 hours at a temperature of 60℃~100℃ to ensure that the solidified proppant can be completely cured.

[0016] (vi) After sealing the hollow position with a consolidation proppant, connect the hollow directional tool to the drilling tool and send it into the designated position of the branch wellbore according to the set construction procedure before starting construction.

[0017] In the above technical solution, the consolidation proppant is the HLC-SCC type consolidation proppant or a similar consolidation proppant product with a glass transition temperature >200℃ produced by the Engineering Technology Branch of CNOOC Energy Development Co., Ltd. The type of consolidation proppant can be consolidable coated quartz sand or coated ceramsite; the mesh size of the consolidation proppant is 20-40 mesh or 30-50 mesh; the glass transition temperature of the consolidation proppant after curing is >200℃; the initial uniaxial compressive strength of the consolidation proppant is greater than 10MPa, and the temporary plugging strength retention rate is >20% after aging at reservoir temperature for 20 days.

[0018] In the above technical solution, the liquid curing agent is formed by mixing a solute and a solvent in a volume ratio of 1:(30-50), wherein the solute is any one or a mixture of several of m-phenylenediamine, m-xylenediamine, diethylenetriamine or maleimide.

[0019] The beneficial effects of this invention are:

[0020] This invention provides a method for temporarily plugging hollow directional drilling rigs using consolidated proppant, which differs from the technical route of temporarily plugging hollow directional drilling rigs using soluble metals or soluble polymers. This method can significantly improve the temperature resistance of hollow directional drilling rigs, and is especially suitable for well types with bottom hole temperatures exceeding 150°C, or even reaching 200°C. Utilizing the permeability of the consolidated proppant, it can effectively isolate the main wellbore from the branch wells during the drilling stage, and also enable oil production after well completion. Furthermore, as the consolidated proppant remains at the bottom of the well, the consolidated body can naturally degrade and detach. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below through specific embodiments.

[0022] Example 1

[0023] Hollow stainless steel pipes were used to simulate the hollow section of a hollow directional drilling rig. A solidifying proppant was filled into the pipes, and the pipes were heated to solidify. Then, they were placed in an aging tank containing drilling fluid and hot-rolled at 190°C for different times. The permeability after hot-rolling for different times was tested to simulate whether the directional drilling rig could be produced normally during the production stage. The compressive strength of the pipes after hot-rolling for different times was tested to assess its degradation at high temperatures. This experiment successfully simulated the entire process of a hollow directional drilling rig from temporary plugging to production in a laboratory setting using hollow stainless steel pipes, verifying the reliability of the method. The specific steps are as follows:

[0024] (i) Mix 20-40 mesh HLC-SCC type solid support agent and m-phenylenediamine diluted 50 times with water at a volume ratio of 1:1 and set aside.

[0025] (ii) Plug the bottom of the hollow inclined device (hollow stainless steel tube) with a rubber stopper, fill the hollow stainless steel tube with the mixed solidification support and liquid curing agent, and compact and flatten the top surface of the solidification support from the top with an iron rod slightly smaller than the inner diameter of the stainless steel tube.

[0026] (iii) Place the hollow stainless steel tube containing the solidification proppant in a 60°C water bath for 48 hours to allow the solidification proppant to solidify completely.

[0027] (iv) Place the fully cured hollow stainless steel pipe with the solidified proppant completely solidified in an aging tank containing drilling fluid and heat-roll it at 190°C for 10 days, 20 days, 30 days and 50 days respectively.

[0028] (v) Take out hollow stainless steel tubes that have been hot rolled for different times (10d, 20d, 30d, 50d), use a press to displace the solidified proppant in the hollow stainless steel tubes, and test the permeability and uniaxial compressive strength of the solidified proppant body.

[0029] The test results are shown in the table below.

[0030] 1 0 7.89 7.02 2 10 7.13 6.59 3 20 6.83 6.35 4 30 7.05 4.14 5 50 6.65 2.13

[0031] The hollow directional thruster manufactured using the temporary plugging method of this invention has a certain degree of permeability in the hollow area after temporary plugging. During the drilling stage, drilling fluid leakage can be controlled by matching the solid particle size of the drilling fluid. After well completion, negative pressure backflow unplugs the temporary plugging layer in the hollow area of ​​the hollow directional thruster, allowing fluids such as oil and gas to pass through the temporary plugging layer, thus enabling normal production after well completion and solving the problem of insufficient temperature resistance of traditional temporary plugging materials. As the production time extends, the resin in the solidified proppant will gradually fail at high temperatures (above 150°C), thereby losing its ability to bind the proppant. The solidified proppant in the hollow area of ​​the hollow directional thruster will also gradually degrade and fall off naturally, thus completely opening the fluid channels of the entire directional thruster.

[0032] The temporary plugging method of this invention uses coated quartz sand or coated ceramic particles of a certain specification as a consolidation proppant. After consolidation, this type of consolidation proppant can have a high permeability, ensuring that a temporary plugging layer with a certain temperature resistance and permeability can be formed inside the hollow inclined plane after the consolidation of the proppant. Unlike the traditional temporary plugging method that uses materials with degradation function, even if the temporary plugging layer is not degraded, it will not affect normal production.

[0033] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for temporarily plugging a hollow directional drilling tool in a high-temperature well with a consolidated proppant, characterized in that: Includes the following steps: (i) Determine the amount of consolidation proppant to be used and weigh it for later use; The consolidated proppant is a consolidateable coated quartz sand or coated ceramsite; the mesh size of the consolidated proppant is 20-40 mesh or 30-50 mesh; the glass transition temperature of the consolidated proppant after curing is >200℃; the initial uniaxial compressive strength of the consolidated proppant is greater than 10MPa, and the temporary plugging strength retention rate is >20% after aging at reservoir temperature for 20 days; (ii) Seal the bottom of the hollow section of the hollow inclined plane; (iii) After weighing the solidified proppant and liquid curing agent in step (i), mix them evenly and fill them into the hollow position of the hollow inclined device, and compact and level the top. The volume ratio of the solidification support to the liquid curing agent is 1:(0.8-1.5). The liquid curing agent is composed of a solute and a solvent mixed in a volume ratio of 1:(29~49), wherein the solute is any one or a mixture of several of m-phenylenediamine, m-xylenediamine, diethylenetriamine or maleimide; (iv) Wrap a heating sleeve around the hollow part of the hollow inclined plane and heat it until the solidification proppant is completely cured; The hollow inclined plate is heated for 48 hours at a temperature of 60℃ to 100℃.

2. The method for temporarily plugging a hollow directional drilling tool in a high-temperature well using a consolidated proppant according to claim 1, characterized in that: The amount of consolidation proppant used is determined based on the volume of the area to be temporarily plugged in the hollow directional thruster and the bulk density of the consolidation proppant, and the calculation formula is as follows: m=ρ×V×α In the formula: m is the mass of the consolidated proppant, in grams; ρ is the bulk density of the consolidated proppant, in g / cm³. 3 α is an additional coefficient, ranging from 1.1 to 1.3; V is the volume of the area to be temporarily blocked in the hollow inclined plane, in cm³. 3 .

3. The method for temporarily plugging a hollow directional drilling tool in a high-temperature well using a consolidated proppant according to claim 1, characterized in that: The bottom of the hollow position of the hollow inclined plate is sealed with a soft rubber plug.

4. The method for temporarily plugging a hollow directional drilling tool in a high-temperature well using a consolidated proppant according to claim 1, characterized in that: The heating range of the heating jacket at least covers the hollow part of the hollow inclined plane.