CN103615237B - A kind of microelement interwell tracer agent and application thereof - Google Patents

Abstract

The invention discloses a kind of microelement interwell tracer agent and application thereof, relate to oil-field flooding slight trace agent and this tracer using method in deposit dynamic monitoring. Utilize in stratum and contained fluid thereof not or containing atomic trace element as tracer, high molecular weight hydrophilic complex and rare earth element is adopted to carry out complexation preparation tracer, inject from injecting well, then withdrawal well sampling around is specified by certain sampling, monitor its output situation, sample is analyzed, draws spike production curve. Slight trace agent provided by the invention, stability is high, be easy to accurately determine and alter groove and fracture orientation outside the thickness of Water Flooding Layer and permeability, macropore diameter, water flooding well pipe.

Description

A kind of microelement interwell tracer agent and application thereof

Technical field

The invention belongs to oil field injection and extraction technical field, relate to a kind of tracer, be specifically related to a kind of microelement interwell tracer agent and application process thereof.

Background technology

Enter the oil field in waterflooding extraction later stage, due to oil reservoir respectively to the imbalance of Hydrodynamic field in infiltrative difference, profit viscosity differences and development process, injection water monolayer in the vertical certainly will be caused to advance by leaps and bounds and the tonguing phenomenon in plane, make producing well premature water breakthrough, and moisture content is more and more higher. Now recovery percent of reserves is low, and substantial amounts of remaining oil remains in oil reservoir.

Oil-field flooding tracer technique is one of produced on-site measuring technology, and its principle is from injecting well injection tracer. Then withdrawal well sampling around is specified by certain sampling, monitor its output situation. sample is analyzed, draw tracer production curve, then it is fitted, the connection situation of oil-water well in reflection waterflooding extraction process, grasp and inject the direction of propulsion of water, displacement velocity, sweep area and reservoir heterogeneity and remaining oil saturation distribution etc., thus instructing the design of oilfield exploitation and the adjustment of latter period of oilfield development. When adding a certain amount of tracer in water injection well, it can be dissolved in the water, and forms the abundance zone of a slug-wise, follows the trail of and injects water, and labelling injects the movement locus of water. By monitoring the concentration production curve of tracer, appliance computer numerical analysis means in surrounding oil well, just can feed back oil-yielding stratum geologic parameter and inject the flow performance of water. Current Tracer Technique decapacitation is determined and is altered groove outside the thickness of Water Flooding Layer and permeability, macropore diameter, water flooding well pipe and interlayer is altered and outside fracture orientation etc., can also reflecting the contradiction between the change of water filling layer position internal water flooding amount, each water filling layer position and residual oil in water drive field distribution etc., the reasonable development for oil field provides important evidence.

For a long time, the most frequently used in oil field development tracer mainly has chemical tracer and isotopic tracer. Although these tracer techniques are widely used in each oil field, but there is also shortcoming in various degree: chemical tracer consumption is generally all relatively big, cost is high, detection error is bigger;Isotopic tracer then requires it must is professional construction personnel, and application specific equipment Inspection is unfavorable for large-scale promotion application.

CN1699998A discloses a kind of for the constant material tracer in oilfield monitoring process and this tracer using method in deposit dynamic monitoring, the tracer wherein provided is lanthanide series, is any one or more in lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutecium and scandium and yttrium totally 17 kinds of elements; It is be respectively synthesized its water soluble complex that any one or more in these 17 kinds of elements is used as the tracer in oil field; This water soluble complex in this oil field stratum water without element or the little element of content make, the chelating agent used is ethylenediaminetetraacetic acid: EDTA, EDETATE SODIUM salt, ethylenediamine ethoxy triacetic acid, diethylenetriamine pentaacetic acid, nitrilotriacetic acid: NTA and TBP-EDTA system, any one or more in P350-EDTA system, and utilize tracer interpretation software that test result is processed, obtain the various dynamic parameter of oil reservoir.

Multiple tracer is separately had to be disclosed report, including inorganic salts, dyestuff, alcohols, isotope etc., to adapt to various working condition. But current tracer monitoring technique yet suffers from certain deficiency, mainly existing tracer major part heat resistance is poor, and these tracers can not bear the high salinity of oil reservoir, when high salinity, can there is chemical reaction in tracer, lose the function of spike. Additionally, the high salinity of oil reservoir can produce serious matrix effect, have a strong impact on analysis precision, even result in analysis result and lost efficacy. High salinity also can cause analytical tool atomization system, sampling system to block simultaneously, causes the damage of analytical tool and the interruption of analysis.

On the other hand, chemical tracer monitoring technology is in oil field practice application, along with carrying out of block tracer monitoring, tracer monitoring technology develops to block many well groups whole monitoring gradually, and require that tracer disclosure satisfy that high temperature, high salinity formation condition, the kind of tracer and detection means are had more, update, higher requirement, as a block to throw in multiple (such as more than 5 kinds) and consumption is few, transport and the chemical tracer of easy construction simultaneously, and supporting corresponding detection means and injected system, can be only achieved the purpose of monitoring. Current tracer monitoring technology is not met by the demand of above-mentioned monitoring, accordingly, it would be desirable to carry out stable performance, high salinity high temperature resistant, resistance to, the research of novel tracers that accuracy of detection is high and screening, and corresponding analyzing detecting method research.

And trace matter detection is called forth generation technology (or being called special chemical tracer), the trace element that utilization does not have in stratum and contained fluid thereof or content is atomic is as tracer, detection technique is advanced, using the advanced instrument detections such as ICP-Q, detection minimum detectability can reach the rank of 10-15 (ppq level). As 21 century new technique, it inherits the advantage of isotopic tracer, has again the technical characteristic of oneself simultaneously.

Summary of the invention

In order to solve the technical problem in prior art, the purpose of the present invention aims to provide a kind of microelement interwell tracer agent and preparation method thereof, overcome the little problem of temperature range that uses, and this tracer can add at well head or be layered and add, samples conveniently, it is not necessary to professional participates in; Consumption is few, viable economically;Optional quantity is more, it is possible to meets and adds and test sample requirement with layered.

The invention provides a kind of microelement interwell tracer agent, structural formula is as follows:

One or more in M selected from cerium, dysprosium, erbium, europium, terbium, scandium, neodymium, samarium, holmium, thulium, lutecium, promethium element, X is the electronegative group that charge balance is required.

According to specific embodiments of the present invention, preferred M be terbium, scandium, neodymium, samarium, holmium, thulium one or more, X is fluoboric acid root, fluorophosphoric acid root, acetate or halide ion.

The preparation method that present invention also offers the positively charged part of described tracer, shown according to the following formula.

One or more in M selected from cerium, dysprosium, erbium, europium, terbium, scandium, neodymium, samarium, holmium, thulium, lutecium, promethium element.

The method includes: is dissolved in oxolane by double; two for 350ml in reaction process pyridine derivates with three times of molar excess of rare earth terchoride, the solution in mixture is cooled to-78 DEG C, stirs 2 hours, then instill the aqueous solution of 100mmol potassium hydroxide. At-78 DEG C after 1 hour, and add being dissolved in oxolane of twice mole under refluxAnd boil 6 hours, make reactant mixture in ambient temperature overnight. Remove oxolane followed by a rotary evaporator, and extract residue with acetas. Product, through purified by silica gel chromatography, uses the amino-silica gel with acetas-petroleum ether as eluent.

The metal complex of the present invention is to pass through slaine, for instance a kind of metal halide thing carries out with the reaction of corresponding ligand, it is preferable that carry out halogen ion exchange by hexafluorophosphoric acid salt anionic or six borate anions.

Productivity: 500mg, purity (HPLC): 93%

Mass spectrum (ms) (PosLIMS): 1455.5=complex

Productivity: 2.95g (79%)

IR (KBr/ solid phase) [cm^-1]:557,627,855,1524,1128,1217,1353,1499,1689vs.2787

MS-50:(180℃,70eV,300μA,m/e):gef.:643,2566

Additionally, present invention also offers the method that the above-mentioned complex prepared is used for oil field inter-well tracer test dynamic monitoring, concrete method includes:

(1) analyze oilfield injection water and output water, select corresponding tracer;

(2) design implementation scheme, the lowest detectable limit according to the farthest well spacing of well group, reservoir thickness, moisture content, porosity and instrument, amplify 60-80 times, calculate the tracer consumption added;

(3) 10m is added³Prepad fluid, be subsequently adding 20m³Tracer injects liquid;

(4) by the sampling period that the cycle is 15-325 days in monitoring well sampling, it is standardized sample processing, ICP-Q type icp ms is utilized to carry out correspondence analysis, draw tracer production curve, utilize conventional tracer digital-to-analogue software to be simulated calculating, terminate to analyze test.

The present invention is compared with existing disclosed patent, and advantage specifically includes that

1. stable without pyrolytic conversion (being resistant to-100 DEG C～1500 DEG C high/low temperature); 2. overcome radioactivity safety that may be present and environment hidden danger; 3. well head adds or is layered and adds, samples conveniently, it is not necessary to professional participates in; 4. consumption is few, viable economically; 5. optional quantity is more, it is possible to meets and adds and test sample requirement with layered; 6. Measurement Resolution is higher, it is possible to more fine seizure reservoir information.

Detailed description of the invention

The 6 kinds of tracer code names filtered out in the present embodiment are Q1, Q2, Q3, Q4, Q5 and Q6, and wherein Q1, Q2, Q3, Q4, Q5 and Q6 represent the complex that rare earth element is terbium, scandium, neodymium, samarium, holmium and thulium respectively. These 6 kinds of tracers have been done following experiment:

(1) oilfield injection water and output water are analyzed, it is therefore an objective in order to study the compatibility situation of chelating agent and formation water

The purpose of compatibility experiment is the compatibility situation measuring tracer with highly mineralized formation brines, and experimental technique is as follows:

Compound concentration is Q1, Q2, Q3, Q4, Q5 and Q6 enveloping agent solution of 10 μ g/L, 20 μ g/L, 30 μ g/L respectively, then 1:1 is about the formation water of 20000mg/L and mixes with salinity by volume.Stand at 350 DEG C of temperature after overnight, then measure the concentration change of each tracer element, study the interfering ion impact on tracer concentration, and interfere situation between tracer, it is desirable to the light transmittance of mixed solution is more than 90%. Interfere and compatibility experimental result.

Table 1

From upper table 1: the light transmittance of mixed solution is all higher than 90%, meet the requirement of the light transmittance of mixed solution in industry standard.

(2) tracer application analysis

The formation water in monitored oil field or oil well and source water being carried out on the basis of background concn high-resolution complete analysis, by reservoir condition design quantity, add from well head; Then, by observing well wellhead sampling and sample treatment, purification, to tracked tracer high speed detection simultaneously on high-resolution test equipment, and utilize tracer interpretation software that sample detection result is processed, obtain dynamic parameter; Finally, it is analyzed explaining to tracer analysis result and software processes result in conjunction with on-the-spot oil-water well Production development, it is provided that the various dynamic datas needed for client. The enforcement step of this method of testing is as follows:

1, formulate test implementation scheme, select including block, well group, target zone, inject well, monitoring well pound sign, test purpose, essential implementation, scheduling etc.;

2, oil field water is carried out complete analysis, it is determined that after background concn, select above-mentioned several slight trace agent;

3, tracer consumption is determined in calculating. According to the well spacing of well group, reservoir thickness, porosity, moisture content, percent continuity and the data such as instrument, lowest detectable limit, follow these steps to and formula calculate the trace matter detection consumption (be generally several grams to upper hectogram) of use:

First, the maximum dilution volume injecting stratum is calculated:

Vp=π r²·h·Ф·Sw·Er

In formula:

Vp-maximum dilution volume, m³;

R-injects the distance of well and sampled well, m;

H-injects well effective thickness, m;

Sw-layer of sand water saturation, %;

Er-percent continuity, %;

φ--porosity, %

Secondly, the dosage of tracer is calculated:

A=μM of DL Vp

In formula:

A-μ tracer consumption, gram;

μ-assurance coefficient;

MDL-instrument lowest detectable limit;

4, injecting well by design quantity to tracer to add and anticipate the complex solution prepared, dosing method adopts well head specific purpose tool directly add at well head or adopt waterflood-transmission line to inject;

5, the cycle be 15-325 days sampling period monitoring well sampling, sample is standardized process;

6, utilize resolution up to ppq level (1 × 10^-15) inductively coupled plasma mass spectrometry instrument (ICP-Q) sample is analyzed in time, and draw tracer production curve;

Water sample measurement result such as table 2 below:

Table 2

7, utilize tracer interpretation software that tracer production curve is fitted, obtain formation parameter distribution situation and actual fluid-channeling channel parameter;

8, according to formation parameter distribution situation, analyze and inject fluid level channelling situation, by tracer time, well spacing are calculated, obtain channelling direction and speed;

9, according to actual fluid-channeling channel parameter, fluid longitudinally actual channelling situation is obtained in conjunction with profile-log of water injection or steam injection well steam entry profile;

10, utilize above-mentioned matching explanation results, analyze main flow, main bleed-through road channelling parameter and connection situation;

11, according to the geological model set up, conventionally oil reservoir heterogeneity evaluation method, calculate the coefficient of heterogeneity (Lorenz constant, coefficient of permeability variation etc.) obtaining being correlated with, carry out oil reservoir heterogeneous body situation analysis;

12, utilize crude oil or viscous crude migration rule simulation softward to explain and tracer numerical simulation software, relevant dynamic and static and Production log data make an explanation, obtain remaining oil saturation distribution situation.

Tracer good stability provided by the invention, construction is simple, and measuring accuracy is high, has very big promotional value, has great importance to improving Exploitation Level of Oilfield further. The injection mode of slight trace agent, detection method and this tracer using method in deposit dynamic monitoring can adopt the method disclosed in prior art.

Above-described embodiment compares and is intended to readily appreciate preparation method of the present invention trend of properties of product on technical arrangement plan. So that those skilled in the art can know the innovation essence grasping technical solution of the present invention, not only lift up out the embodiment of restriction in function or properties of product. So in addition to the implementation, the present invention can also have other polynary embodiment. All employings are equal to replacement or the technical scheme of equivalent transformation formation, all fall within the protection domain of application claims.

Claims (5)

1. a microelement interwell tracer agent, it is characterised in that:

One or more in M selected from cerium, dysprosium, erbium, europium, terbium, scandium, neodymium, samarium, holmium, thulium, lutecium and promethium element, X is the electronegative group that charge balance is required.

2. tracer as claimed in claim 1, it is characterised in that: described M selected from terbium, scandium, neodymium, samarium, holmium, thulium one or more, X is fluoboric acid root, fluorophosphoric acid root, acetate or halide ion.

3. tracer as claimed in claim 1 or 2, it is characterised in that: add, before injecting well, tracer is configured to water soluble complex.

4. tracer as claimed in claim 3, it is characterised in that: described M is selected from neodymium, and X is fluoboric acid root.

5. the application in deposit dynamic monitoring of the tracer as described in any one of claim 1-4, its sign is in that: the consumption that makes of described tracer is trace, and the application in deposit dynamic monitoring of the described tracer comprises the steps:

(1) analyze oilfield injection water and output water, select suitable tracer;

(2) design implementation scheme, the lowest detectable limit according to the farthest well spacing of well group, reservoir thickness, moisture content, porosity and instrument, amplify 60-80 times, calculate the tracer consumption added;

(3) 10m is added³Prepad fluid, be subsequently adding 20m³Tracer injects liquid;

(4) by the sampling period that the cycle is 15-325 days in monitoring well sampling, it is standardized sample processing, ICP-Q type icp ms is utilized to carry out correspondence analysis, draw tracer production curve, utilize conventional tracer digital-to-analogue software to be simulated calculating, terminate to analyze test.