CN102928522A - Method for measuring degassing efficiency of drilling fluid through complete degassing value - Google Patents

Abstract

The invention relates to a method for measuring the degassing efficiency of a drilling fluid through a complete degassing value process. The method comprises the following steps: taking a sample of the drilling fluid before the drilling fluid enters an electric degassing device, carrying out thermal vacuum quantitative complete degassing analysis to detect the total content of hydrocarbon gases in the drilling fluid before the degassing of the electric degassing device, and allowing the drilling fluid to enter the electric degassing device; taking the sample of the drilling fluid at the outlet of the electric degassing device, and carrying out the thermal vacuum quantitative complete degassing analysis to detect the content of the hydrocarbon gasses in the drilling fluid after the degassing of the electric degassing device; and calculating to obtain the ratio of the content after the degassing to the content before the degassing, and calculating to obtain the degassing efficiency which is a difference between 1 and the ratio, wherein the ratio is the proportion of the gases residual in the drilling fluid, The degassing efficiency of the drilling fluid is of great importance to the discovery, the explanation and the evaluation of a hydrocarbon reservoir, and the degassing efficiency is utilized to carry out the real time correction of the gas measuring value in the well logging process, enhance the accuracy of well logging data and provide bases for the horizontal comparison between wells and the later explanation and evaluation of the well logging data.

Description

A kind of method of entirely taking off value measurement drilling fluid degassing efficiency

Technical field

The invention belongs to oil exploration and development fields, relate in particular to a kind of method that the value method is measured the drilling fluid degassing efficiency of entirely taking off.

Background technology

In the petroleum prospecting compound logging, by means of equipment such as drilling fluid degasifier, chromatographs, but the content of hydrocarbon gas in the on-line measurement drilling fluid is used for finding, explains, estimates show of oil and gas.What the scene was the most frequently used is engine degasser, and its market share is more than 90%.When degassed, drilling fluid enters degasifier from the engine degasser bottom, flowed out by the drilling fluid outlet after motor stirs, drilling fluid is deviate from the gas in the drilling fluid under the effect that motor stirs, and the gas of deviating from enters chromatograph by gas vent and carries out the concentration detection under the effect of sample air pump.

When degasifier is degassed, the gas in the drilling fluid all can not be deviate from, be remained in the drilling fluid greatly.The gas flow of deviating from accounts for the ratio of total gas content in the drilling fluid, is referred to as " degassing efficiency ".The value of degassing efficiency is not of uniform size, so can't learn the real content of gas in the drilling fluid, the evaluation that shows to oil gas brings difficulty.Degassing efficiency is a concept at present, and few people systematically measure.

In the prior art, patent 1: permanent efficiency degassing device (application number CN200420019970.8), this patent has been announced a kind of permanent efficiency degassing device, point out that this device has constant degassing efficiency, but do not introduce numerical value and the computing method of degassing efficiency, thus can't learn the real content of gas in the drilling fluid, can't quantitative evaluation stratum oily what, the across comparison that is unfavorable for log data brings difficulty for discovery and the interpretation and evaluation of hydrocarbon zone.

Patent 2: Full-automatic vacuum degasser and degas method thereof (application number CN200910034214.X), this patent has been announced a kind of Full-automatic degassing device, have the advantages such as degassing efficiency is stable, but do not introduce numerical value and the computing method of degassing efficiency, so can't learn the real content of gas in the drilling fluid, can't quantitative evaluation stratum oily what, be unfavorable for the across comparison of log data, bring difficulty for discovery and the interpretation and evaluation of hydrocarbon zone.

Huang Xiaogang, hair have quickly been delivered " computing method of gas detection logging hydro carbons gas composition degassing efficiency " in " well logging engineering " fourth phase in 2008, proposed to measure the method for degassing efficiency, he utilizes repeatedly the degassed mode that adds up to measure, his method has three shortcomings: the one, and the method is only applicable to the FLEX degasifier, the FLEX degasifier generally is only applicable to the deep-sea well logging, very low in the Chinese market occupation rate at present, do not have ubiquity, representativeness; The 2nd, because that the degasification process of FLEX degasifier at a confined space, can be carried out in this space continuously is degassed, and that the highest engine degasser of existing market popularity rate can't repeat is degassed, so the method is only applicable to the FLEX degasifier; The 3rd, the method complex operation.

Summary of the invention

The present invention is in order to solve the technical matters that exists in the prior art, and on the basis of existing technology, the inventor draws the method for measuring the drilling fluid degassing efficiency through research and development.The method is applicable to on-the-spot the most frequently used engine degasser, and applicability is wide, and is simple to operate.

The present invention for the scheme that realizes goal of the invention and adopt is:

A kind of engine degasser entrance entirely takes off value-engine degasser outlet and entirely takes off the method that value is measured the drilling fluid degassing efficiency, described method enters the engine degasser porch at drilling fluid and gets the drilling fluid sample, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the total content of hydrocarbon gas in the degassed front drilling fluid of engine degasser; Get the drilling fluid sample in the engine degasser exit afterwards, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the content of hydrocarbon gas in the degassed rear drilling fluid of engine degasser; Calculate engine degasser and be the shared ratio of " residual " gas in drilling fluid with the ratio of degassed front hydrocarbon gas content after degassed, 1 is degassing efficiency with the difference of this ratio.

In order to realize the above-mentioned purpose that obtains degassing efficiency, the present invention includes:

(1) the drilling fluid sample was got by described elder generation before drilling fluid enters engine degasser, carried out thermovacuum and quantitatively entirely took off analysis, and for detection of the total content of hydrocarbon gas in the degassed front drilling fluid of engine degasser, process comprises the steps:

Step 1: before degassed, get the drilling fluid sample in engine degasser drilling fluid porch, the container that thermovacuum is quantitatively taken off analyser is entirely got completely and is as the criterion;

Step 2: the drilling fluid sample that will get is put into thermovacuum and is quantitatively entirely taken off analyser analysis;

Step 3: collect the volume that thermovacuum quantitatively takes off gas that analyser is deviate from entirely, ml;

Step 4: composition and the content of the gas of deviating from the chromatograph analysis.

(2) get the drilling fluid sample in the engine degasser exit after described, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the content of hydrocarbon gas in the degassed rear drilling fluid of engine degasser, its process comprises the steps:

Step 5: after degassed, get the drilling fluid sample in engine degasser drilling fluid exit;

Step 6: the degassed rear drilling fluid sample that will get is put into thermovacuum and is quantitatively entirely taken off analyser analysis;

Step 7: collect the volume that thermovacuum quantitatively takes off gas that analyser is deviate from entirely, ml; Step 8: composition and the content of the gas of deviating from the chromatograph analysis.

In the concrete experiment,

The kind of gas that described chromatograph detects comprises methane, ethane, propane, isobutane, normal butane, isopentane, n-pentane;

Thermovacuum quantitatively entirely takes off analyser and analyzes drilling fluid volume 250ml.

Concrete according to the analysis of carrying out before degassed, obtain the total content of hydrocarbon gas in the degassed front drilling fluid, and obtain the content of hydrocarbon gas in the drilling fluid after degassed after degassed, obtain degassing efficiency:

Output rusults obtains drilling fluid degassing efficiency method:

Degassing efficiency can be tried to achieve by formula:

$\mathrm{\η}=(1-\frac{V_{\mathrm{ia}}{C}_{\mathrm{ia}}}{V_{\mathrm{ib}}{C}_{\mathrm{ib}}})\×100\%$

η-degassing efficiency, dimensionless;

V _Ib-before degasifier, get the drilling fluid sample to do and entirely take off the gas volume that analysis is deviate from, ml;

C _Ib-before degasifier, get the drilling fluid sample to do and entirely take off the gas concentration that analysis is deviate from, %;

V _Ia-get the drilling fluid sample in degasifier drilling fluid outlet to do and entirely take off the gas volume that analysis is deviate from, ml;

C _Ia-get the drilling fluid sample in degasifier drilling fluid outlet to do and entirely take off the gas concentration that analysis is deviate from, %;

The kind of gas that i-detects;

V _IbC _IbBe illustrated in and get the drilling fluid sample before the degasifier and carry out thermovacuum and quantitatively entirely take off the molal quantity of analyzing collected hydrocarbon gas; V _IaC _IaBeing illustrated in degasifier drilling fluid outlet gets the drilling fluid sample and carries out thermovacuum and quantitatively entirely take off the molal quantity of analyzing collected hydrocarbon gas; The ratio of " residual " hydrocarbon gas in drilling fluid after the expression degasifier is degassed, 1 is degassing efficiency with the difference of this ratio.

The method that the present invention researches and develops has successfully been measured the drilling fluid degassing efficiency.When carrying out the quantitative evaluation explanation of hydrocarbon zone, can be according to each component degassing efficiency, inverse goes out the real content of gas in the drilling fluid, strengthens the accuracy of data evaluation.

1. can be used to find and estimate weak show of oil and gas;

Some original well show of oil and gas because degassing efficiency is very low, causes the gas measured value very low, probably causes hydrocarbon zone to find to collect and estimates difficulty.After measuring certain condition degassing efficiency, according to the gas measured value, can extrapolate real gas content in the drilling fluid, the weak show of oil and gas of correct understanding.

But 2. what of quantitative evaluation stratum oily;

In well logging work in the past, owing to not knowing the exact value of degassing efficiency, can't learn real gas content in the drilling fluid.After measuring degassing efficiency, can extrapolate real gas content in the drilling fluid, can carry out quantitative evaluation to the stratum.

3. the across comparison that is conducive to log data.

Be subjected to the restriction of degassing efficiency, can't learn real gas content in the drilling fluid, the show of oil and gas that the low show of oil and gas of gas measured value is might not the gas measured value high is poor, and the data between the different wells can't contrast.After measuring degassing efficiency, can extrapolate real gas content in the drilling fluid, realize the data contrast between the different wells.

Description of drawings

Fig. 1 is each component degassing efficiency curve map of the experiment well of embodiment

Concrete accompanying drawing content is illustrated in connection with embodiment.

Embodiment

The present invention is by following three processes:

(1) before drilling fluid enters engine degasser, gets the drilling fluid sample, carry out thermovacuum and quantitatively entirely take off analysis, in order to detect the total content of hydrocarbon gas in the degassed front drilling fluid of engine degasser.

(2) get the drilling fluid sample in drilling fluid engine degasser exit, carry out thermovacuum and quantitatively entirely take off analysis, in order to detect the content of hydrocarbon gas in the degassed rear drilling fluid of engine degasser.

(3) " degassed after " be the shared ratio of " residual " gas in drilling fluid with " before degassed " ratio, 1 with it difference be degassing efficiency.

Method comprises:

(1) the degassed front parameter measurement of engine degasser:

This parameter mainly utilizes thermovacuum quantitatively entirely to take off analyser and chromatograph is analyzed, and its process is:

1. get the drilling fluid sample engine degasser drilling fluid porch (before being degassed), the container that thermovacuum is quantitatively taken off analyser is entirely got completely and is as the criterion, and is generally 250ml;

2. the drilling fluid sample that will get is put into thermovacuum and is quantitatively entirely taken off analyser analysis, and working specification is referring to " thermovacuum quantitatively takes off analyser entirely " operation instructions;

3. collect the volume that thermovacuum quantitatively takes off gas that analyser is deviate from entirely, ml;

Composition and the content of the gas of 4. deviating from the chromatograph analysis, the composition of its analysis depends on chromatographic sensing range, existing chromatograph generally can detect methane, ethane, propane, isobutane, normal butane, isopentane, n-pentane etc.

(2) the degassed rear parameter measurement of engine degasser:

1. (being degassed rear) gets the drilling fluid sample in engine degasser drilling fluid exit;

2. other operations are identical with " the degassed front parameter measurement of engine degasser " method.

(3) Output rusults namely obtains drilling fluid degassing efficiency method:

According to top description, degassing efficiency can be tried to achieve by formula:

$\mathrm{\η}=(1-\frac{V_{\mathrm{ia}}{C}_{\mathrm{ia}}}{V_{\mathrm{ib}}{C}_{\mathrm{ib}}})\×100\%$

η-degassing efficiency, dimensionless;

V _Ib-before degasifier, get the drilling fluid sample to do and entirely take off the gas volume that analysis is deviate from, ml;

C _Ib-before degasifier, get the drilling fluid sample to do and entirely take off the gas concentration that analysis is deviate from, %.

V _Ia-get the drilling fluid sample in degasifier drilling fluid outlet to do and entirely take off the gas volume that analysis is deviate from, ml;

C _Ia-get the drilling fluid sample in degasifier drilling fluid outlet to do and entirely take off the gas concentration that analysis is deviate from, %;

The kind of gas that i-detects comprises methane, ethane, propane, isobutane, normal butane, isopentane, n-pentane;

V _IbC _IbBe illustrated in and get the drilling fluid sample before the degasifier and carry out thermovacuum and quantitatively entirely take off the molal quantity of analyzing collected hydrocarbon gas; V _IaC _IaBeing illustrated in degasifier drilling fluid outlet gets the drilling fluid sample and carries out thermovacuum and quantitatively entirely take off the molal quantity of analyzing collected hydrocarbon gas;

Be degassed through degasifier after the ratio of " residual " hydrocarbon gas in drilling fluid, 1 is degassing efficiency with the difference of this ratio.

In the method, only need carry out twice thermovacuum quantitatively takes off analysis entirely, and every kind of component of degassing efficiency value that can obtain methane, ethane, propane, isobutane, normal butane, isopentane, n-pentane finally all can obtain corresponding degassing efficiency.

This test is tested test findings such as table 1, Fig. 1 at five mouthfuls of wells such as certain oil field Y224, L97, LS102, H89, B26.Can be found out by Fig. 1, table 1, every mouthful of degassing efficiency that well is drawn, its curve is basic identical, and a common rule is arranged, and is exactly the increase along with carbon number, and degassing efficiency reduces gradually, the degassing efficiency of methane is generally about 20%, and the degassing efficiency of isobutane only has about 7%, thus explanation, and the carbon number of hydrocarbon gas is larger, the ability that is adsorbed in the drilling fluid is stronger, deviate from more difficultly from drilling fluid, degassing efficiency is lower, and this conforms to theoretical.In the well logging process, can utilize this value that the gas measured value is carried out real time correction, strengthen the accuracy of log data, be the across comparison between well and the well, and the interpretation and evaluation in log data later stage lays the foundation.

Each component degassing efficiency reckoner of table 1

Claims (5)

1. an engine degasser entrance entirely takes off value-engine degasser outlet and entirely takes off the method that value is measured the drilling fluid degassing efficiency, it is characterized in that, described method is got the drilling fluid sample in the engine degasser porch, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the total content of hydrocarbon gas in the degassed front drilling fluid of engine degasser; Get the drilling fluid sample in the engine degasser exit afterwards, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the content of hydrocarbon gas in the degassed rear drilling fluid of engine degasser; Calculate engine degasser and be the shared ratio of " residual " gas in drilling fluid with the ratio of degassed front hydrocarbon gas content after degassed, 1 is degassing efficiency with the difference of this ratio.

2. a kind of method that value-entirely take off value is measured the drilling fluid degassing efficiency of entirely taking off according to claim 1, it is characterized in that, the drilling fluid sample was got by described elder generation before drilling fluid enters engine degasser, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the total content of hydrocarbon gas in the degassed front drilling fluid of engine degasser, process comprises the steps:

Step 1: before engine degasser is degassed, get the drilling fluid sample in engine degasser drilling fluid porch, the container that thermovacuum is quantitatively taken off analyser is entirely got completely and is as the criterion;

Step 2: the drilling fluid sample that will get is put into thermovacuum and is quantitatively entirely taken off analyser analysis;

Step 3: collect the volume that thermovacuum quantitatively takes off gas that analyser is deviate from entirely, ml;

Step 4: composition and the content of the gas of deviating from the chromatograph analysis.

3. a kind of method that value-entirely take off value is measured the drilling fluid degassing efficiency of entirely taking off according to claim 1, it is characterized in that, get the drilling fluid sample in the engine degasser exit after described, carry out thermovacuum and quantitatively entirely take off analysis, for detection of the content of hydrocarbon gas in the degassed rear drilling fluid of engine degasser, its process comprises the steps:

Step 5: after engine degasser is degassed, get the drilling fluid sample in engine degasser drilling fluid exit;

Step 6: the degassed rear drilling fluid sample that will get is put into thermovacuum and is quantitatively entirely taken off analyser analysis;

Step 7: collect the volume that thermovacuum quantitatively takes off gas that analyser is deviate from entirely, ml;

Step 8: composition and the content of the gas of deviating from the chromatograph analysis.

4. described a kind of value-entirely take off method that value is measured the drilling fluid degassing efficiency of entirely taking off one of according to claim 1-3, it is characterized in that, according to the analysis of carrying out before degassed, obtain the total content of hydrocarbon gas in the degassed front drilling fluid, with degassed after obtain the content of hydrocarbon gas in the drilling fluid after degassed, obtain degassing efficiency:

Output rusults obtains drilling fluid degassing efficiency method:

Degassing efficiency can be tried to achieve by formula:

$\mathrm{\η}=(1-\frac{V_{\mathrm{ia}}{C}_{\mathrm{ia}}}{V_{\mathrm{ib}}{C}_{\mathrm{ib}}})\×100\%$

η-degassing efficiency, dimensionless;

V _Ib-before degasifier, get the drilling fluid sample to do and entirely take off the gas volume that analysis is deviate from, ml;

C _Ib-before degasifier, get the drilling fluid sample to do and entirely take off the gas concentration that analysis is deviate from, %;

V _Ia-get the drilling fluid sample in degasifier drilling fluid outlet to do and entirely take off the gas volume that analysis is deviate from, ml;

C _Ia-get the drilling fluid sample in degasifier drilling fluid outlet to do and entirely take off the gas concentration that analysis is deviate from, %;

The kind of gas that i-detects;

V _IbC _IbBe illustrated in and get the drilling fluid sample before the degasifier and carry out thermovacuum and quantitatively entirely take off the molal quantity of analyzing collected hydrocarbon gas; V _IaC _IaBeing illustrated in degasifier drilling fluid outlet gets the drilling fluid sample and carries out thermovacuum and quantitatively entirely take off the molal quantity of analyzing collected hydrocarbon gas; Expression

The ratio of " residual " hydrocarbon gas in drilling fluid after degasifier is degassed, 1 is degassing efficiency with the difference of this ratio.

5. one of according to claim 2-4 described a kind of value-entirely take off the method that the value method is measured the drilling fluid degassing efficiency of entirely taking off is characterized in that,

The kind of gas that described chromatograph detects comprises methane, ethane, propane, isobutane, normal butane, isopentane, n-pentane;

Thermovacuum quantitatively entirely takes off analyser and analyzes drilling fluid volume 250ml.