CN-121991646-A - Phase change composite material for oil-based drilling fluid and preparation method and application thereof

CN121991646ACN 121991646 ACN121991646 ACN 121991646ACN-121991646-A

Abstract

The invention provides a phase change composite material for oil-based drilling fluid, a preparation method and application thereof, wherein the phase change composite material for the oil-based drilling fluid comprises the following components: phase change base material, amination modified porous material, modified asphalt and macrocyclic compound molecule cucurbituril [ n ]. The preparation method comprises the steps of mixing NaNO 3 、KNO 3 and LiNO 3 , heating, cooling and crushing to obtain a phase-change basic substance, modifying expanded graphite and/or montmorillonite to obtain an amination modified porous material, adding macrocyclic compound molecular cucurbituril [ n ] in an aqueous solution of the amination modified porous material to obtain a first suspension, preparing the phase-change basic substance into a solution, adding the solution into the first suspension to obtain a second suspension, calcining the second suspension to obtain a first phase-change composite material, dissolving modified asphalt in petroleum ether to obtain a third suspension, dispersing the first phase-change composite material in the third suspension, freezing, vacuum filtering and drying to obtain the phase-change composite material for the oil-based drilling fluid.

Inventors

Tang Wenyue
ZOU CHANGJUN
XIAO FENGFENG
LIANG HAO
RAN QIHUA
LUO YUFENG
PENG BIQIANG
TAN JIEYUN
YANG YE
KANG JINGXIN

Assignees

中国石油天然气集团有限公司
中国石油集团川庆钻探工程有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (10)

1. The phase change composite material for the oil-based drilling fluid is characterized by comprising a phase change base substance, an amination modified porous material, modified asphalt and macrocyclic compound molecular cucurbiturils [ n ].
2. The phase change composite material for oil-based drilling fluids according to claim 1, wherein the phase change base material is nitrate co-crystal composed of NaNO 3 、KNO 3 and LiNO 3 , the aminated modified porous material is amino expanded graphite and/or amino montmorillonite, the modified asphalt is one or more of acrylic resin modified asphalt, polyethylene modified asphalt and petroleum resin modified asphalt, the macrocyclic compound molecule cucurbituril [ n ] is one or more of cucurbituril [5], cucurbituril [6] and cucurbituril [7], and the molar ratio of NaNO 3 、KNO 3 to LiNO 3 is 2:3:2 to 3:2:2.
3. The phase change composite material for oil-based drilling fluids according to claim 1, wherein the phase change temperature of the phase change composite material for oil-based drilling fluids is 133.9-143.2 ℃, and the particle size of the phase change composite material is 35-68 μm.
4. A method for preparing the phase change composite material for oil-based drilling fluid according to any one of claims 1 to 3, wherein the preparation method comprises the following steps: S1, mixing NaNO 3 、KNO 3 and LiNO 3 , heating, cooling and crushing to obtain the phase change base material; s2, modifying the expanded graphite and/or montmorillonite to obtain the amination modified porous material; S3, adding the macrocyclic compound molecular cucurbituril [ n ] into the aqueous solution of the amination modified porous material to obtain a first suspension, preparing the phase change basic substance into a solution, adding the solution into the first suspension to obtain a second suspension, and calcining the second suspension to obtain a first phase change composite material; s4, dissolving the modified asphalt in petroleum ether to obtain a third suspension, dispersing the first phase-change composite material in the third suspension, and then freezing, vacuum filtering and secondary drying to obtain the phase-change composite material for the oil-based drilling fluid.
5. The preparation method of the phase-change composite material for the oil-based drilling fluid, which is characterized in that the molar ratio of NaNO 3 、KNO 3 to LiNO 3 is 2:3:2-3:2:2, and the ratio of the amination modified porous material, the macrocyclic compound molecular cucurbituril [ n ], the modified asphalt and the phase-change base material is 1:1:2:10-1:2.5:5:10.
6. The preparation method of the phase change composite material for the oil-based drilling fluid, which is disclosed in claim 4, is characterized in that the heating temperature is 235-250 ℃, the heating time is 10-12 hours, the dispersing stirring speed is 1000-1300 r/min, the dispersing stirring time is 20-30 min, the freezing temperature is-5-8 ℃, the freezing time is 1-3 hours, the secondary drying temperature is 80-100 ℃, and the secondary drying time is 10-12 hours.
7. The method for preparing a phase change composite material for an oil-based drilling fluid according to claim 4, wherein the step S2 further comprises the steps of: S21, dispersing the amination modified porous material in water for ultrasonic treatment and adjusting the amination modified porous material into an acidic solution to obtain a first solution; s22, adding the silane coupling agent aqueous solution into the first solution to obtain a second solution; S23, mixing the first solution and the second solution, carrying out alkylation reaction, and drying for the first time after removing unreacted silane coupling agent to obtain the amination modified porous material.
8. The method for preparing the phase-change composite material for the oil-based drilling fluid according to claim 7, wherein the pH value of the acidic solution is 3-5, the ultrasonic treatment time is 30-50 min, the alkylation reaction temperature is 80-100 ℃, the alkylation reaction time is 22-24 h, the primary drying temperature is 80-100 ℃, and the primary drying time is 22-24 h.
9. The method for preparing a phase change composite material for an oil-based drilling fluid according to claim 4, wherein the step S3 further comprises the steps of: s31, stirring the first suspension for 8-12 hours at 80-85 ℃; and S32, stirring the second suspension for 7-9 h at the temperature of 60-65 ℃.
10. The use of the phase change composite material for oil-based drilling fluids according to any one of claims 1 to 3 in oil-based drilling fluids, wherein the addition amount of the phase change composite material for oil-based drilling fluids in the oil-based drilling fluids is 6wt.% or less based on the total weight of the oil-based drilling fluids.

Description

Phase change composite material for oil-based drilling fluid and preparation method and application thereof Technical Field The invention relates to the field of oilfield drilling, in particular to a phase change composite material for oil-based drilling fluid, a preparation method thereof and application thereof in the oil-based drilling fluid. Background At present, the energy demands of petroleum and natural gas are rapidly increased, the exploitation of conventional oil and gas reservoirs enters the exhaustion stage, and deep and ultra-deep oil and gas reservoirs need to be developed to meet the continuously increased energy demands of human beings. The oil-based drilling fluid has the advantages of high temperature stability, good lubricity, formation hydration expansion resistance, high drilling speed, good sand carrying performance, strong pollution resistance and the like, and is widely used for deep wells, high-temperature high-pressure wells, complex wells, water-sensitive formations, salt-containing bottom layers and the like. Along with the continuous increase of drilling depth, formation temperature continuously rises, and long-time drilling process produces a large amount of heat simultaneously, and traditional oil-based drilling fluid's heat transfer ability is relatively poor, can not timely transfer the heat to lead to bottom hole assembly and drilling fluid temperature to rise, make drill bit and rotatory direction instrument receive the harm, can't transmit effective information to the earth's surface, and then hinder the normal clear of drilling operation. Particularly, when the horizontal well oil-based drilling fluid is drilled, the failure rate of the rotary guiding tool at the bottom of the well at 120-150 ℃ is up to 32%. Thus, capturing and storing the formation and the heat energy generated by friction of the drill bit with the formation is critical to successful completion of the drilling operation. At present, a ground cooling device can be used for reducing the temperature of the well bore returning drilling fluid, but the method can only indirectly reduce the circulating temperature of the drilling fluid in the well bore by reducing the inlet temperature of the drilling fluid, the cooling requirements of high-temperature drilling fluid at the bottom of the well and a drilling tool can not be met, and huge energy loss exists. The phase change material (PHASECHANGE MATERIALS, PCM) absorbs or releases heat in the phase change process, and the characteristic is reasonably utilized, so that the temperature in a shaft can be effectively reduced, and the distribution of the shaft fluid temperature field is changed. However, the phase change material may cause leakage problems when converting from a solid to a liquid. The drilling fluid phase change temperature control material is often encapsulated by microencapsulation, porous material molding, coaxial classical spinning and other encapsulation methods, so that the leakage problem is avoided. The method can wrap the phase change material in a certain space to isolate the phase change material from contacting with the external environment, so that the leakage problem when the phase change material is in a solid state to a liquid state can be solved, and the problems of increasing the volume, increasing the heat transfer area and reducing the temperature control effect of the phase change material in the phase change process can be controlled. For example, publication No. CN115491183A discloses a preparation method and application of a high-temperature and high-pressure resistant microsphere for active cooling of a high-temperature drilling fluid, wherein a phase change core material of the microsphere is an organic polymer material (paraffin modified composite material), a wall material is nano silicon dioxide, the organic polymer phase change material is modified and sprayed at high pressure, the high-temperature and high-pressure resistance of the microsphere is improved by an in-situ polymerization method, the nano silicon dioxide forms a compact shell by a self-assembly deposition mode, and the particle size of the phase change microsphere is controllable. The phase-change microspheres are used for cooling water-based drilling fluid, and cannot be used for cooling oil-based drilling fluid for deep wells and horizontal wells. The publication No. 2024.03.15 and the publication No. CN117701255A disclose a phase change capsule for cooling drilling fluid, a preparation method and application thereof, wherein the core material of the capsule is a mixture of NaNO 3 and KNO 3, the shell material is silicon dioxide, and cellulose nanofibrils supplement the shell, so that the mechanical strength of the capsule can be improved, and the thermodynamic performance of the capsule can be improved. However, the phase-change microspheres can only be used for cooling water-based drilling fluid, but cannot be used for cooling oil-based drilling f