CN101769149B - CO2 injection profile well logging method - Google Patents

Abstract

The invention relates to a CO2 injection profile well logging method. The method comprises the following two steps of: (1) before opening a well, injecting and filling diesel oil in a blowout prevention pipe by a pump; after the diesel oil is filled in the blowout prevention pipe, injecting grease into a blowout preventer at the mouth of the well, and observing the pressure change of the mouth ofthe well; when the pressure of the mouth of the well reaches 1.2 times higher than the injection pressure of the well, opening a testing valve and observing for 10-20 minutes; after determining that the mouth of the well and a sealing blowout preventer have no leakage, loading an instrument into the well; and (2) through solving for fluid densities of different depths of the CO2 injection profilewell, converting the mass flow rate according to a measured volume flow rate. The CO2injection profile well logging method prevents CO2 from leaking in a construction process and prevents ice barriers from forming; and temperature and pressure parameters are recorded, and the mass flow rate of fluid in the well is solved through the temperature and pressure parameter and the volume flow rate so as to accurately and truly reflect a true suction condition of stratums.

Description

CO 2Injection profile well logging method

Technical field:

The present invention relates to a kind of logging method in oil reservoir logging field, specifically a kind of CO ₂Injection profile well logging method.

Background technology:

At the middle and advanced stage of oil field development,, successively adopted methods such as water filling, polymer injection, notes trielement composite material, steam injection to keep higher strata pressure and driven to flow to the interior oil of pit shaft in the stratum voluntarily in order to improve recovery ratio to greatest extent.To some water drive starting pressure is high, water filling is difficult and because of the oil field of clay swell water injection capacity along with the increase variation of water injection rate, experiment proves CO ₂Injection technique can obtain effect preferably.CO ₂Physical property receive the influence of temperature and pressure very big, CO after pressure descends ₂Swelling heat absorption; Fluid temperature (F.T.) in the pipeline can be reduced to-30～-50 ℃; Condensing of effluent gases dry ice and the gas outlet caliber is dwindled even can to produce temporary ice stifled makes gas flow not smooth, well head pressure; Downstream pressure and gas production, temperature are the shakiness of fluctuation or the phenomenons such as blowing of tic formula on the flow meter, make test bring very big harm.Well temperature and pressure are along with the increase of well depth raises.When well temperature be higher than 31.26 ℃, when pressure is 7.29MPa, CO in the well ₂Become the supercritical fluid state.Because the well intake pressure of different wells is different, the degree of depth of perforated interval is different, then CO ₂The density of fluid receives the degree of depth, pressure, temperature variation at continuous variation, CO ₂The flow regime of fluid is not sure of.The measurement result of tester is volume flow at present, and the variation of fluid density must cause the variation of fluid volume.The gained measurement result can not correctly reflect the true suction condition on stratum so, and inconsistent with the ground continuous data.

Summary of the invention:

The objective of the invention is provides a kind of CO in order to overcome the deficiency of prior art ₂Injection profile well logging method, this CO ₂Injection profile well logging method prevents CO in work progress ₂Leak, it is stifled to prevent to form ice; Through admission temperature, pressure parameter, and can accurately reflect the true suction condition on stratum truly through the mass flow that temperature, pressure parameter and volume flow are asked for borehole fluid.

The technical scheme content that the present invention adopted is: this CO ₂Injection profile well logging method, this method comprises two parts:

(1), before driving a well, in lubricator, inject and be full of diesel oil with pump, after diesel oil is full of lubricator; In wellhead blowout preventor, annotate stop-leak compound, can adjust the stop-leak compound viscosity, and observe the well head pressure variation according to environment temperature; When well head pressure reaches 1.2 times greater than the injection pressure of well, open the test valve, observed 10～20 minutes; After confirming well head and sealing the blowout hookup leakproof, with the instrument G.I.H; Can not have the decline phenomenon through observing the well head pressure table, observe sealing device and be connected each position leakproof phenomenon and bleed off pipe with well head and do not have fluid and flow out definite leakproof.

(2), pass through CO ₂Injection profile logging adds thermometric degree, pressure parameter; Utilize barometric gradient to ask for the fluid density of different depth; All pressure datas are carried out 20m pressure reduction calculate, ask for the density value that obtains each depth point, can converse mass flow according to the volume flow that records again.

The invention has the beneficial effects as follows: the present invention is mainly by preventing CO in the analysis of log data and the work progress ₂Leaking, form the stifled measures two parts of ice forms.Through admission temperature, pressure parameter, and can accurately reflect the true suction condition on stratum truly through the mass flow that temperature, pressure parameter and volume flow are asked for borehole fluid.CO ₂The main advantage of the oxygen activation logging method that injection profile oxygen activation logging technology adopts be in real time in the monitor well any instrument can arrive the fluid state of the degree of depth; Through to managing inside and outside fluid measurement; The deficiency of can also be as required institute before constructing being done to design existence replenish and perfect, the contradiction, the doubtful point that occur in the data admission process are carried out repetition measurement and checking targetedly; Improve the confidence level of data effectively, reduced the probability of secondary construction.

The method of the lubricator notes diesel oil that the well head sealing is adopted is the interior CO of barrierwell effectively ₂Gas flow.Under the well head pressure effect, have only and dissolve on a small quantity in the diesel oil, under the effect of stop-leak compound injected system, these gases that dissolve in diesel oil can't spill in the outside air.

Because gas volume is stressed very big with Influence of Temperature, the pressure and temperature of different depth is deferred to certain Changing Pattern in the well.This technology provides the mass flow that converts out through the pressure, temperature variation rule in final explanation results.Make the user more clear, also be convenient to the analysis and the utilization of the situation of injecting simultaneously the injection situation.

Description of drawings:

Fig. 1 is that 100-1740m density is with change in depth figure;

Fig. 2 is that the above volume flow of injection well downhole flow regulator is with change in depth figure;

Fig. 3 is that 1260-1600m density is with change in depth figure;

Fig. 4 is fragrant 180-129 well impulse neutron oxygen activation logging interpretation results table.

The specific embodiment:

Below in conjunction with embodiment the present invention is described further:

This CO ₂Injection profile well logging method comprises two parts:

One, for prevent in the well or the gas injection pipeline in carbon dioxide liquid in lubricator, form dry ice because of pressure descends, cause downhole instrument can't play generation into the lubricator phenomenon.Before driving a well, in lubricator, inject and be full of the very little diesel oil of compressible coefficient with pump.After diesel oil is full of lubricator, in wellhead blowout preventor, annotates stop-leak compound and observe the well head pressure variation.When well head pressure reaches 1.2 times greater than the injection pressure of well, open the test valve.Observed 10～20 minutes, and confirmed behind well head and the sealing blowout hookup leakproof the instrument G.I.H.To guarantee getting into the CO in the lubricator at the initial stage that drives a well ₂Gas can only have and a spot ofly dissolves in diesel oil and do not reveal (guarantee well head pressure do not change, promptly do not produce pressure drop).

Two, in order accurately to reflect the true suction condition on stratum truly, guarantee the ground continuous data in underground survey result's uniformity, be example with fragrant 180-129 well: we are to all CO ₂Injection profile logging all adds thermometric degree, pressure parameter, utilizes barometric gradient to ask for the method for the fluid density of different depth, all pressure datas is carried out 20m pressure reduction calculate, and asks for the density value that obtains each depth point.And the density value of being obtained carried out quadratic regression.

A. density calculation:

Δ P=ρ g Δ h formula (1)

Density to 1200 meters-1600 meters well sections is carried out linear fit, obtains fitting formula to be:

Y=-0.0002x+1.18 formula (2)

Find out that thus the variable density of this well section is merely 0.02g/cm for per hundred meters ³, therefore, we ignore to the variable density of measuring well section 1770m---1860m.

B. flow conversion:

Follow mass conservation law, the above mass flow of perforation layer should remain unchanged, at 1768.41m:

The quality ÷ actual measurement volume flow formula (3) that ρ=perforation layer is above

＝31.67×10 ³kg/d÷.42.91m ³/d

＝0.738g/cm ³

1. the basic condition of well: table 1

2. situation before surveying: table 2

Production technology:

Injection allocation pressure: 14.0MPa

Injection allocation flow: 35m 3/d

3. collection overview: table 3

4. gather the data quality evaluation:

1) this well data is (injection pressure is 14.3MPa) admission in confined conditions, and instrument is in proper working order during well logging, has reflected the suction situation of each layer under the normal injection condition.Tubing string Curve Tool position display is clear.

2) accomplished after the normal data admission, carried out duplicate measurements again, measurement result is in the allowed band of error.

5. data preliminary treatment: this well explains that the degree of depth is as the criterion with well logging transverse electric depth measurement degree.

6, explanation and evaluation:

1), impulse neutron oxygen activation logging as a result opinion release outcome table 4.

2), according to the absolute soakage and a relative soakage of each layer of survey well log interpretation outcome table explanation, judgement master, inferior water accepting layer and pouring-stop layer.

3), well has 4 perforation layers entirely, divides 8 measuring points to measure, and under the injection pressure of 14.0MPa, has 2 sections that the demonstration of suction is arranged.Be respectively (1780.1-1781.6m) section, F17 (1850.1-1851.9m) section of F13 (2).

7, volume flow explanation results:

(1780.1-1781.6m) the section soakage is the highest for F13 (2), and absolute soakage is 24.6m ³/ d, soakage is 57.3% relatively; F17 (1850.1-1851.9m) section, absolute soakage is 18.3m ³/ d, soakage is 42.7% relatively.

8, mass flow explanation results:

(1780.1-1781.6m) the section soakage is the highest for F13 (2), and absolute soakage is 18.2t/d, and soakage is 57.3% relatively; F17 (1850.1-1851.9m) section, absolute soakage is 13.5t/d, soakage is 42.7% relatively.

Annotate: volume flow is scaled mass flow needs fluid density value.This well log interpretation calculates through pressure gradient method and match obtains eccentric above pit shaft inner fluid density p=0.738g/cm ³The following fluid density of off-centre obtains (owing to institute's measuring pressure is an oil pipe internal pressure value, so near the density value that perforated interval, is calculated by barometric gradient does not reflect extratubal fluid density, the eccentric following density value that near the density of perforated interval is used unified calculation that reaches) by following formula:

ρ＝m/v m＝31.7t/d v＝42.9m ³/d ρ＝0.74g/cm ³

Virtue 180-129 well impulse neutron oxygen activation logging interpretation results table

Table 4

Claims (1)

1. CO ₂Injection profile well logging method, this method comprises two parts:

(1), before driving a well; In lubricator, inject and be full of diesel oil with pump, after diesel oil is full of lubricator, in wellhead blowout preventor, annotates stop-leak compound and observe the well head pressure variation; When well head pressure reaches 1.2 times greater than the injection pressure of well; Open the test valve, observed 10～20 minutes, confirm behind well head and the wellhead blowout preventor leakproof the instrument G.I.H;

(2), pass through CO ₂Injection profile logging adds thermometric degree, pressure parameter; Utilize barometric gradient to ask for the fluid density of different depth; All pressure datas are carried out 20m pressure reduction calculate, ask for the density value that obtains each depth point, can converse mass flow according to the volume flow that records again.

Images