Organic boron-zirconium cross-linking agent and preparation method thereof

Abstract

The invention provides an organic boron-zirconium cross-linking agent and a preparation method thereof, and belongs to the technical field of oilfield fracturing fluids. The invention provides a preparation method of an organic boron-zirconium cross-linking agent, and the preparation method is used for solving the problems of expensive selected raw materials, strict preparation conditions, cumbersome preparation procedures and the like of the existing organic boron-zirconium cross-linking agent during preparation. The preparation method comprises the following steps: adding inorganic zirconium salt and isopropanol in water, uniformly stirring, then introducing ammonia gas and carrying out a reflux reaction at 55-60 DEG C for 0.5-1 hour; then adding polyhydric alcohols, alpha-hydroxyl sodium carboxylate and alkanolamine, continuing to react for 2-4 hours, then adding the boron solution prepared from an inorganic boron compound and methanol, and continuing to react for 2-4 hours, thereby obtaining the organic boron-zirconium cross-linking agent. The preparation method provided by the invention is moderate and easily controllable in preparation conditions, and simple in preparation process and easy to operate; the organic boron-zirconium cross-linking agent prepared by the method is applied to a high-temperature-resistant fracturing fluid system, and the formed gel has good temperature resistance and shear resistance at a high temperature above 135 DEG C.

Description

technical field [0001] The invention relates to oilfield fracturing fluid technology, in particular to an organoboron-zirconium crosslinking agent used in a high-temperature resistant fracturing fluid system and a preparation method thereof. Background technique [0002] Oilfield fracturing technology is a major measure for oil and gas well stimulation, and it is widely used in various oilfields. It uses ground high-pressure pumps to pump fracturing fluid into the formation with a displacement that greatly exceeds the absorption capacity of the formation, forming cracks in the formation, improving the conductivity of oil and gas layers, and achieving the purpose of increasing production. [0003] Fracturing fluids have undergone tremendous evolution since they were first used to stimulate fractures in 1947. The early fracturing fluid was to add viscous fluid enough to open and extend fractures to gasoline; later, with the increase of well depth and well temperature, higher ...

AI Technical Summary

Problems solved by technology

Organometallic (titanium, zirconium) cross-linked fracturing fluid systems have the advantages of high temperature resistance and delayed cross-linking. However, the jelly formed by this type of cross-linking agent is severely degraded mechanically under high-speed shearing, and has poor proppant-carrying ability. Moreover, the jelly formed by it does not have the ability to completely break the gel and degrade in a short time, resulting in serious damage to the conductivity of the support crack; the organoboron crosslinking agent has the advantages of good solubility and delayed crosslinking characteristics, but its formation The temperature resistance of jelly has certain limitations; organoboron zirconium crosslinking agent combines the advantages of organometallic crosslinking agent and organoboron crosslinking agent, which can effectively improve the temperature resistance and shear resistance of the fracturing fluid system High efficiency, low dosage, and delayed cross-linking

[0006] There have been many studies on how to prepare organoboron-zirconium crosslinking agents, such as: The organoboron-zirconium crosslinking agent invented by the US patent US5217632 is made of zirconium α-hydroxycarboxylate such as zirconium lactate as raw material, after reacting with polyol for a period of time, and then reacting with inorganic boron and sodium hydroxide for a period of time Apparently, this method uses expensive organic zirconium as raw material, which has high cost and low economic benefit; Cross-linking agent OBZ-1 (Zhang Wensheng, Qin Liping. Organoboron-zirconium cross-linking agent OBZ-1 for fracturing fluid[J]. Oilfield Chemistry, 1996, 13 (3): 210-212.) and Xin Jun, Southwest Petroleum University The organoboron-zirconium crosslinking agent BA1-21 developed by et al. (Guo Jianchun, Xin Jun, Wang Shibin, et al. Development and application of abnormally high temperature guar gum fracturing fluid system[J]. Petroleum Drilling Technology, 2010, 32 (3): 64-67.) is to introduce organoboron zirconium complexes into organoboron under strictly controlled reaction conditions to obtain organoboron zirconium crosslinking agent. The organoboron colloidal particles are firmly bonded by zirconium ions to form larger colloidal particles, thus increasing the crosslinking density and crosslinking strength, this preparation method needs to strictly control the reaction conditions, the operation process is complicated, and it is not conducive to the market production of organic zirconium boron crosslinking agent; Wang Dong et al. from Zhongyuan Oilfield prepared a high-temperature delayed organoboron-zirconium crosslinking agent CZB-03 (Wang Dong, Wang Junying, Liu Hongsheng, et al. Water-based fracturing fluid high-temperature delayed Preparation of type organoboron zirconium crosslinking agent CZB-03[J]. Oilfield Chemistry, 2004, 21 (2): 113-115.), the crosslinking agent is compounded by organoboron and organozirconium crosslinking agent, The temperature resistance of the formed fracturing fluid system is higher than 160°C, but this preparation method is to synthesize the organoboron crosslinking agent and the organozirconium crosslinking agent separately, and then compound to obtain the organoboron zirconium crosslinking agent. The method is divided into three steps Carried out separately, the procedure is cumbersome and time-consuming; US Patent US7683011 invented the organoboron-zirconium crosslinking suitable for 135~163℃ reservoir The agent is reacted with alkanolamine and zirconium complex and then reacted with water and hydroxyalkylene diamine , and finally reacted with boron compounds, but this method is also prepared through complicated steps using expensive organic zirconium complexes as raw materials

[0007] It can be seen from the above that when preparing organoboron-zirconium crosslinking agents, the raw materials used are expensive, the preparation conditions are harsh, and the preparation procedures are cumbersome, which greatly reduces the The economic benefits of organoboron-zirconium crosslinking agents have been hindered, and the market production and wide application of organoboron-zirconium crosslinking agents in high-temperature resistant fracturing fluid systems have been further hindered.

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