阅读说明：本技术 一种油田耐高盐高碱度水溶性微量元素示踪剂的制备方法 (Preparation method of oil field high-salt-resistance high-alkalinity water-soluble trace element tracer ) 是由 郑冻冻 史胜龙 温庆志 张东晓 房堃 于 2019-10-17 设计创作，主要内容包括：本发明属于水平井分段压裂示踪监测的技术领域,具体的涉及一种油田耐高盐高碱度水溶性微量元素示踪剂的制备方法。将可溶性稀土盐与络合剂通过络合形成稀土络合物,即得该微量元素示踪剂；其中络合剂为乙二胺四乙酸、磺基水杨酸钠、羟基乙酸、氨三乙酸三钠和二乙烯三胺五乙酸五钠中的至少一种。该方法所得的微量元素示踪剂可以同时耐高碱和高矿化度。(The invention belongs to the technical field of staged fracturing tracing monitoring of horizontal wells, and particularly relates to a preparation method of a high-salinity-resistant high-alkalinity water-soluble trace element tracer for an oil field. Complexing soluble rare earth salt and a complexing agent to form a rare earth complex, thus obtaining the trace element tracer; wherein the complexing agent is at least one of ethylenediamine tetraacetic acid, sodium sulfosalicylate, glycolic acid, trisodium nitrilotriacetate and pentasodium diethylenetriaminepentaacetate. The trace element tracer agent obtained by the method can resist high alkali and high mineralization simultaneously.)

1. A preparation method of a water-soluble trace element tracer agent with high salt and high alkalinity resistance for an oil field is characterized in that a soluble rare earth salt and a complexing agent are complexed to form a rare earth complex compound, and the trace element tracer agent is obtained; wherein the complexing agent is at least one of ethylenediamine tetraacetic acid, sodium sulfosalicylate, glycolic acid, trisodium nitrilotriacetate and pentasodium diethylenetriaminepentaacetate.

2. The preparation method of the oil field high-salinity-and-alkalinity-resistant water-soluble trace element tracer according to claim 1, wherein the molar ratio of the soluble rare earth salt to the complexing agent is 0.02-1: 0.003 to 0.6.

3. The method for preparing the water-soluble trace element tracer agent with high salt and alkalinity resistance for the oil field according to claim 1, wherein the soluble rare earth salt is at least one of rare earth nitrate, rare earth sulfate and rare earth hydrochloride.

4. The preparation method of the oil field high-salinity-and-alkalinity-resistant water-soluble trace element tracer according to claim 1, which is characterized by comprising the following specific steps: firstly, soluble rare earth salt is added to the degree of mineralization of 1 x 10⁴～20×10⁴mg/L and the pH value of 1-12, then adding a complexing agent, mixing, stirring for 1-3 hours, and complexing to obtain a rare earth complex, namely the tracer.

5. The water-soluble trace element tracer agent for resisting high salt and high alkalinity of oil field is characterized in that the mineralization degree of the tracer agent is 1 multiplied by 10⁴～20×10⁴mg/L; the pH resistance value is 1-12; the high temperature resistance is 300-350 ℃.

Technical Field

The invention belongs to the technical field of staged fracturing tracing monitoring of horizontal wells, and particularly relates to a preparation method of a high-salinity-resistant high-alkalinity water-soluble trace element tracer for an oil field.

Background

There are many types of tracers currently used in trace monitoring technology, and they can be classified into chemical tracers, radioactive tracers, isotopic tracers, and trace element tracers according to the age of the tracer. Chemical tracer is on the stratum surface, and then adsorbs less, and the consumption is little, and the kind is many, is easily detected by spectrophotometer method, but because this type of tracer needs the ore field operation, and the quantity is big, and its is with high costs, adaptability and selectivity are poor, and test resolution is low, can cause environment and personnel's safety problem, this type of tracer is the trend of eliminating gradually. The radioactive isotope tracer has radioactivity, is not safe to personnel and environment, and is limited in application. Although the stable isotope tracer has no radioactive hazard, less dosage and simple and convenient field operation, the application of the stable isotope tracer is limited because the variety of the stable isotope tracer is less, and the analysis and test means of the stable isotope tracer are complicated and expensive. The trace element tracer is used as a fourth generation tracer technology, has the advantages of no radioactivity, no pollution, corrosion resistance, good safety and stability, small using amount, direct addition from a well mouth, low price, low cost, high analysis precision, multiple selectable methods and the like, and has become the development direction of the current tracer technology.

The tracer monitoring technology still has certain not enough at present, and the main most temperature resistance of current tracer is poor, can not bear 300 ℃ high temperature under the general condition, even some tracers can bear so high temperature, these tracers also can not bear the high degree of mineralization of oil reservoir, under the high degree of mineralization condition, the tracer can take place chemical reaction, appears deposiing, loses the function of tracer. The problem when selecting the complexing agent is that the complexing agent can become clear when being added into the mineralized liquid containing rare earth salt, but if the adding amount of the complexing agent is small, the mineralized liquid is also turbid after being added; if the complexing agent is added in an excessive amount, precipitation occurs.

According to research, the maximum salt tolerance of the tracer in the literature is 50000mg/L, and no relevant report that the salt tolerance is more than 50000mg/L exists. At present, the mineralization degree of the western region is 70000mg/L, 80000mg/L and even 200000mg/L, and when the tracer is applied to the oil fields, the mineralization resistance needs to be improved. Therefore, the research and screening of tracers with stable performance, high temperature resistance and high mineralization degree resistance are needed.

Disclosure of Invention

The invention aims to provide a preparation method of a water-soluble trace element tracer with high salt resistance and high alkalinity for an oil field aiming at the technical problem that the tracer in the prior art cannot simultaneously meet the requirements of high temperature resistance, high alkali resistance and high mineralization degree.

The technical scheme of the invention is as follows: a preparation method of a water-soluble trace element tracer agent with high salt and high alkalinity resistance for an oil field comprises the steps of complexing soluble rare earth salt and a complexing agent to form a rare earth complex, thus obtaining the trace element tracer agent; wherein the complexing agent is at least one of ethylenediamine tetraacetic acid, sodium sulfosalicylate, glycolic acid, trisodium nitrilotriacetate and pentasodium diethylenetriaminepentaacetate.

The tracer elements contained in the soluble rare earth salt are as follows: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y) and scandium (Sc), which are elements closely related to 15 elements of the lanthanide series, in total, at least one of 17 rare earth elements.

The mol ratio of the soluble rare earth salt to the complexing agent is 0.02-1: 0.003 to 0.6. The molar ratio between the selected complexing agent and the soluble rare earth salt is creatively designed.

The soluble rare earth salt is at least one of rare earth nitrate, rare earth sulfate and rare earth hydrochloride.

The preparation method of the oil field high-salt-resistance high-alkalinity water-soluble trace element tracer comprises the following specific steps: firstly, soluble rare earth salt is added to the degree of mineralization of 1 x 10⁴～20×10⁴mg/L and the pH value of 1-12, then adding a complexing agent, mixing, stirring for 1-3 hours, and complexing to obtain a rare earth complex, namely the tracer.

A water-soluble trace element tracer agent with high salt and high alkalinity resistance for oil fields,the mineralization resistance of the tracer is 1 multiplied by 10⁴～20×10⁴mg/L; the pH resistance value is 1-12; the high temperature resistance is 300-350 ℃.

The invention has the beneficial effects that: the key point of the preparation method of the oil field high-salt and high-alkalinity water-soluble trace element tracer agent is that the complexing agent is creatively selected to react with the soluble rare earth salt. The selected complexing agent has no pollution to the bottom environment, no harm to personnel, less dosage and low cost; the complex product formed with soluble rare earth salt can resist 20X 10 as tracer⁴mineralization degree of mg/L and formation environment with alkali resistance.

The preparation method provided by the invention has the following characteristics: 1. the method is environment-friendly, pollution-free and safe to operate; 2. the prepared tracer can resist 1X 10⁴～20×10⁴Degree of mineralization in mg/L; 3. the obtained tracer can resist a pH value of 1-12; 4. the obtained tracer can resist the high temperature of 300-350 ℃; 5. the tracer is less in use amount and low in cost; 6. the selectable number is large; 7. the measurement and analysis precision is high.

Drawings

FIG. 1 is a graph showing the reaction results of the soluble rare earth salt and the complexing agent in example 1.

Detailed Description

The present invention will be described in detail below with reference to examples.