阅读说明：本技术 一种稀土元素示踪剂井间监测技术 (Rare earth element tracer interwell monitoring technology ) 是由 邬传威 刘秀明 王亚娜 于 2019-10-15 设计创作，主要内容包括：本发明公开了一种稀土元素示踪剂井间监测技术,包括以下步骤：S1：针对目标水井油井井组,筛选可用的稀土元素示踪剂类型；S2：在选定稀土元素示踪剂类型之后,计算储层中被跟踪流体的最大体积；S3：在确定储层中被跟踪流体的最大体积之后,计算稀土元素示踪剂注入量；S4：巡视井场情况,检测所需设备均可正常运行,将注入示踪剂采用缓慢注入方式,以使注入的示踪剂在井筒中形成适当长度的示踪剂段塞,且段塞中示踪剂分布均匀。本发明所述的一种稀土元素示踪剂井间监测技术,可计算高渗条带厚度、渗透率和喉道半径,计算注入流体驱动速度,了解生产井水、气窜方向,计算注入流体波及面积、波及体积、波及系数。(The invention discloses a rare earth element tracer interwell monitoring technology, which comprises the following steps: s1: screening the types of available rare earth element tracers aiming at a target water well, oil well and well group; s2: after selecting the rare earth element tracer type, calculating the maximum volume of tracked fluid in the reservoir; s3: after determining the maximum volume of tracked fluid in the reservoir, calculating the rare earth element tracer injection amount; s4: and (4) inspecting the well site condition, normally operating equipment required for detection, and injecting the tracer in a slow injection manner so that the injected tracer forms a tracer slug with a proper length in the wellbore, and the tracer in the slug is uniformly distributed. The inter-well monitoring technology of the rare earth element tracer can calculate the thickness, permeability and throat radius of a high-permeability strip, calculate the driving speed of injected fluid, know the water and gas channeling directions of a production well and calculate the swept area, swept volume and swept coefficient of the injected fluid.)

1. A rare earth element tracer interwell monitoring technology is characterized in that: the method comprises the following steps:

s1: screening the types of available rare earth element tracers aiming at a target water well, oil well and well group;

s2: after selecting the rare earth element tracer type, calculating the maximum volume of tracked fluid in the reservoir;

s3: after determining the maximum volume of tracked fluid in the reservoir, calculating the rare earth element tracer injection amount;

s4: inspecting the well site condition, normally operating the equipment required for detection, and slowly injecting the injected tracer to form a tracer slug with a proper length in the wellbore, wherein the tracer in the slug is uniformly distributed;

s5: sampling for months, and detecting the concentration of the rare earth element tracer to the sample by adopting an inductively coupled plasma mass spectrometer to obtain a tracer concentration curve;

s6: inverting the response curve by using semi-analytical method tracer monitoring data interpretation software to obtain parameters such as permeability, throat radius, swept volume, equivalent thickness and the like of the flooded channel;

s7: and cooperating with clients, performing overall analysis on data, combining with multi-party geological data, and finally providing a final development adjustment report to guide oil field development and production.

2. The inter-well monitoring technique of a rare earth element tracer according to claim 1, wherein: the tracer has the following conditions:

1) the injection fluid can be well dissolved and can be transported at the speed of the fluid;

2) a low detection limit;

3) long term chemical stability;

4) no adsorption on the rock surface or around the wellbore;

5) has no chemical reaction with reservoir fluid and no element exchange.

3. The inter-well monitoring technique of a rare earth element tracer according to claim 1, wherein: the maximum volume calculation formula for the tracked fluid is: v = a · H · Φ · S _WWherein A is the well group swept area (m) ²) H is the average thickness (m) of the well group communicating layer, phi is the porosity (%) of the reservoir, S _WIs the reservoir water saturation (%).

4. The inter-well monitoring technique of a rare earth element tracer according to claim 1, wherein: the rare earth element tracer injection amount calculation formula is as follows: q = V · f, where f is an empirical coefficient.

5. The inter-well monitoring technique of a rare earth element tracer according to claim 1, wherein: the theoretical method and the path of the semi-analytical method tracer monitoring data interpretation software comprise calculation of pressure, calculation of flow line, calculation of tracer concentration, adsorption consideration and calculation of wellbore output concentration.

Technical Field

The invention relates to the field of oil well and water well monitoring, in particular to a rare earth element tracer interwell monitoring technology.

Background

In the process of oil field development, because the development of a block needs a plurality of oil-water wells to coordinate production simultaneously, the influence factors caused by injected water on a reservoir are monitored, the monitoring comprises the development direction of a crack, the heterogeneity of the reservoir, the effective condition of initial water injection, the utilization rate of the injected water, the interlaminar utilization condition, the source of produced water, the development condition of a hypertonic strip, the effective condition of an oil well and the like, all the monitoring results have important values for determining the distribution condition of reservoir parameters, carrying out reservoir development and evaluation and determining the design, adjustment and implementation of future development schemes, the current method for directly and intuitively determining more than well parameters is less, the problem can be better solved by the inter-well tracer monitoring technology, the inter-well monitoring technology is to inject a water-soluble tracer into the water injection wells, take water samples from the surrounding monitoring wells and analyze the concentration of the tracer in the taken water samples, and drawing a tracer output curve, and analyzing the tracer output curve by using matched tracer interpretation software to determine the heterogeneous condition of the oil reservoir.

The currently used tracers include chemical tracers (containing dyes, salts), isotopic tracers (including radioactive and non-radioactive tracers). The chemical tracer agent needs to be constructed by means of a special large pump truck, the construction cost is high, and the risk index of the construction process is high. The chemical tracer detection depends on a chromatographic method, the detection precision is low, and errors caused by human factors exist, so that the monitoring result is unstable or the monitoring fails. The rare earth elements have the characteristic of not being adsorbed in the stratum, the injection can be quickly and efficiently realized by matching with special injection equipment, and meanwhile, the extremely high detection precision (can reach ppq level) is achieved by using an inductively coupled plasma mass spectrometer (ICP-MS), so that the industrial application of tracer monitoring is wider, and the selection range of the types of oil field tracers is enriched.

Disclosure of Invention

The invention mainly aims to provide a rare earth element tracer interwell monitoring technology which can effectively solve the problems in the background technology.

In order to achieve the purpose, the invention adopts the technical scheme that:

a rare earth element tracer interwell monitoring technology comprises the following steps:

s1: screening the types of available rare earth element tracers aiming at a target water well, oil well and well group;

s2: after selecting the rare earth element tracer type, calculating the maximum volume of tracked fluid in the reservoir;

s3: after determining the maximum volume of tracked fluid in the reservoir, calculating the rare earth element tracer injection amount;

s4: inspecting the well site condition, normally operating the equipment required for detection, and slowly injecting the injected tracer to form a tracer slug with a proper length in the wellbore, wherein the tracer in the slug is uniformly distributed;

s5: sampling for months, and detecting the concentration of the rare earth element tracer to the sample by adopting an inductively coupled plasma mass spectrometer to obtain a tracer concentration curve;

s6: inverting the response curve by using semi-analytical method tracer monitoring data interpretation software to obtain parameters such as permeability, throat radius, swept volume, equivalent thickness and the like of the flooded channel;

s7: and cooperating with clients, performing overall analysis on data, combining with multi-party geological data, and finally providing a final development adjustment report to guide oil field development and production.

Preferably, the tracer has the following conditions:

1) the injection fluid can be well dissolved and can be transported at the speed of the fluid;

2) a low detection limit;

3) long term chemical stability;

4) no adsorption on the rock surface or around the wellbore;

5) has no chemical reaction with reservoir fluid and no element exchange.

Preferably, the maximum volume calculation formula of the tracked fluid is: v = a · H · Φ · S _WWherein A is the well group swept area (m) ²) H is the average thickness (m) of the well group communicating layer, phi is the porosity (%) of the reservoir, S _WIs the reservoir water saturation (%).

Preferably, the calculation formula of the injection amount of the rare earth element tracer is as follows: q = V · f, where f is an empirical coefficient.

Preferably, the theoretical method and path of the semi-analytical method tracer monitoring data interpretation software comprise calculation of pressure, calculation of flow line, calculation of tracer concentration, adsorption consideration and calculation of wellbore output concentration.

Compared with the prior art, the invention has the following beneficial effects:

in the invention, the thickness, permeability and throat radius of a hypertonic strip can be calculated by using a rare earth element tracer interwell monitoring technology, the driving speed of injected fluid is calculated, the water and gas channeling directions of a production well are known, the swept area, swept volume and swept coefficient of the injected fluid are calculated, so that the distribution of a pressure field and a seepage field can be known, the heterogeneity of a stratum is evaluated, the corresponding effect conditions among wells are analyzed, the interbedded channeling conditions are monitored and evaluated, and the direction of artificial or natural cracks is known, and meanwhile, as the types of the rare earth element tracer are as many as 15, the application range of tracer monitoring is widened, so that the method can realize the following steps: the method comprises the steps of single-well multi-layer tracer monitoring, multi-well single-layer tracer monitoring, multi-well multi-layer tracer monitoring, evaluation of the corresponding conditions of the whole injection and production of a block, evaluation of the water injection effect of single-well component layers, evaluation of the effectiveness of a block well pattern and guidance understanding for the whole adjustment of the block.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.