CN1803695A - CO2 corrosion-prevented cement system for oil well - Google Patents

CO2 corrosion-prevented cement system for oil well Download PDF

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CN1803695A
CN1803695A CN 200610000006 CN200610000006A CN1803695A CN 1803695 A CN1803695 A CN 1803695A CN 200610000006 CN200610000006 CN 200610000006 CN 200610000006 A CN200610000006 A CN 200610000006A CN 1803695 A CN1803695 A CN 1803695A
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corrosion
cement
dcr
sand
dhl
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徐�明
弓玉杰
肖志兴
王广雷
高莉莉
和传健
徐永辉
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Daqing Petroleum Administration Bureau
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Daqing Petroleum Administration Bureau
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Abstract

The invention relates to a cement system for preventing carbon dioxide corrosion in oil wells, which comprises the following constituents (by mass percent): 8-35% of quartz sand or ganister sand, 5-8% of micro silicon powder, 6.5-18% of filtrate loss reduction additive DSJ, DSHJ or DHL, and cement.

Description

The oil well cement system that prevents carbon dioxide corrosion
Technical field:
The present invention relates to the used a kind of cement system in oil drilling field, especially a kind of oil well cement system that prevents carbon dioxide corrosion.
Background technology:
The component of carbonic acid gas Chang Zuowei Sweet natural gas or oil field gas is present in the oil gas, adopts CO 2The raising petroleum recovery technology also can be with CO 2Be brought in the underground environment.CO 2After dissolving in water iron and steel there is extremely strong corrodibility.CO under suitable humidity (relative humidity is greater than 30%) in down-hole and pressure environment condition 2Can cause casing steel general corrosion and serious local corrosion rapidly, make pipeline and equipment that early stage corrosion failure take place, even cause the telescopic corrosion cracking that produces oil.While CO 2Also can produce corrosive nature, reduce the alkalescence of cement stone, cement mantle strength degradation and rate of permeation are increased oil well cement.Along with the increase of carbonizing degree, glued component is destroyed in the cement, and it is big that porosity sharply becomes, and ultimate compression strength seriously falls back, and brings out accidents such as the borehole wall such as fluid channelling, plastic formation collapses and take place.Thereby shorten the production life-span of oil gas well, cause enormous economic loss.
At present, though CO 2The downhole tubular goods etching problem has been caused the attention in domestic each oil field, and carried out corresponding protection against corrosion research, but attention degree is still not enough, especially to CO 2The research of corrosion cement mantle is less, also often there is bigger difference in the safeguard procedures of being taked because of the specific geologic condition in each oil field and the difference of working condition, and the generally popularization of the specific aim safeguard procedures that proposed down for the specified conditions of grand celebration has brought difficulty.In fact, to understand and to implement CO effectively 2To sleeve pipe and the protection of cement mantle corrosive, at first must be from CO 2Sleeve pipe and the theoretical investigation of cement mantle corrosive are started with, and then, just can reach the purpose of controlling " basis " and also obtain good effect in practice in conjunction with theory and test detection and analysis that the field produces environment and the condition of particular locality are passed through system.
Dowell utilizes the high temperature pressure corrosion instrument to study under the various conditions of the U.S. the etching problem of sleeve pipe and cement mantle, and the test of the corrosive environment of High Temperature High Pressure simulated field shows that temperature and pressure is to CO 2Corrosive nature tangible influence is all arranged on speed and degree, several days result of corrosion just catches up with the result of normal temperature and pressure next year sometimes under the High Temperature High Pressure.The former Soviet Union also takes much count of H 2S, CO 2, H 2And the etching problem of water quality, obtained the systematic research result, the feasibility approach by the life-span of indoor simulated hot climate test prediction of result oil well has been proposed under clear and definite down-the hole corrosion medium composition condition.Developed anti-CO abroad 2There is the anti-CO of Dowell in corrosive special cement company 2The FLEXCEM of cement, Halliburton etc.
Domestic Dagang Oilfield adopts natural CO 2Improve the recovery ratio of oil gas, its technical cue is applied cement water reducer exactly, improves cementing quality, reduces CO 2Drive, CO 2To the corrosion of cement mantle, reduced the potentially dangerous of sleeve pipe and cement, cement mantle and formation cementation.
Summary of the invention:
The objective of the invention is to solve the deficiencies in the prior art, a kind of oil well cement system that prevents carbon dioxide corrosion is provided, add control and the control of sanitas well cementation back realization in this cement system to the downhole corrosion phenomenon, prolong the life-span of oil gas well, for exploratory development and safety in production provide safeguard.
The technical solution adopted in the present invention is: this oil well is with preventing that the cement system of carbon dioxide corrosion from comprising following each component: following each component is gross weight proportioning by mass percentage in cement: 8～35% silica sand or quartz sand, 5～8% SILICA FUME, SILICA FUME is represented with DCR, 6.5～18% water retaining DSJ, DSHJ or DHL, cement.
Above-mentioned DSJ is by 75% N,N-DMAA, 5% sodium allylsulfonate, 20% N-vinyl pyrrolidone.
The invention has the beneficial effects as follows: take technique scheme, in cement, add intensity, rate of permeation and the porosity that this sanitas has improved cement mantle, cement stone gas permeability :≤0.1 * 10 -3μ m 2(7d); Cement CO 2Coefficient of corrosion inhibition: 〉=1.0 (intensity of maintenance 7d and the ratio that corrodes preceding intensity in etchant solution), the compactness of cement stone has strengthened, cement stone is fine and close more can to keep higher resistance to corrosion more, forms impermeable membrane after adding superfine silicon dioxide simultaneously, has then increased CO greatly 2Migration resistance in cement mantle, and then can slow down CO 2Corrosion speed to cement mantle.
Below be the experimental technique and the experimental procedure of effect experiment:
Ultimate compression strength, rate of permeation, extent of corrosion and the anticorrosion ability of cement stone estimated in the cement briquette of 1 inch of diameter that compressive strength test is adopted, 1 inch of height.Working method is pressed the API standard fabrication, is positioned over maintenance in the high temperature and pressure protective cauldron, takes out the demoulding.The cement briquette and the corrosive medium that will prepare and number put into CO again 2In the corrosion instrument, observe CO at any time 2Pressure, the temperature variation of corroding instrument are also in time adjusted, and in different following times of etching condition, mensuration is corroded compressive strength of specimens, the changes in permeability rule reaches and the relation of depth of corrosion; In order to obtain the influence rule of relevant influence factor, constantly changing corrosion temperature, CO to depth of corrosion 2Under the different condition of dividing potential drop and etching time, measure the depth of corrosion of different system cement stone samples.CO 2Depth of corrosion to cement stone can be used wet CO 2Technology records, and at first measures CO with quantitative x ray diffraction method under differing temps, pressure 2Crystal form and its content in cement, by a kind of special electron probe microanalysis method the corrosive cement sample is tested then, because by measured data of probe and the calcium carbonate content in the cementitious core is a function of corrosion radial depth, thus can measure cement stone sample under different condition by CO 2The radial distribution thickness of the calcium carbonate layer that the corrosion back generates is depth of corrosion.The corrosion evaluation method of this oil well cement also is an innovation of this project.
Cement strength is with etching time and CO 2The Changing Pattern of dividing potential drop:
Because showing, cement stone corrosive salient features therefore according to this two aspects changes of properties situation or degree, can judge the corrosion condition of cement stone in the variation on ultimate compression strength and the rate of permeation.At 120 ℃, CO 2Dividing potential drop is under the curing condition of 5MPa, comparative analysis normal density (ρ=1.90g/cm 3) ultimate compression strength of cement sample before and after the corrosion of the different curing age of cement formula (see Table 1, table 2 and table 3).
Intensity contrast table (120 ℃) before and after the different curing time cement corrosion of table 1
Numbering The 7d coefficient of corrosion inhibition Prescription 7d ultimate compression strength MPa 14d ultimate compression strength MPa 21d ultimate compression strength MPa 28d ultimate compression strength MPa
Not corrosion Corrosion Not corrosion Corrosion Not corrosion Corrosion Not corrosion Corrosion
1 # 0.86 Dalian G+25% sand 28.57 24.49 25 12.24 24.4 16.32 26.5 16.32
2 # 1.16 Dalian G+25% sand+5%DCR 28.16 32.65 28.57 34.69 32.65 32.65 34.69 36.00
3 # 1.09 Dalian G+25% sand+6.5%DSHJ 22.45 24.49 24.49 20.41 26.53 1224 48.98 18.37
4 # 1.16 Dalian G+25% sand+4%DCR+6.5%DSJ 26.46 30.61 30.77 32.65 33.8 28.57 34.9 31.40
5 # 1.20 Dalian G+25% sand+5%DCR+10.0%DSJ 35.71 42.86 40.82 36.73 34.69 36.73 44.9 41.60
6 # 0.86 Dalian G+25% sand+DHL 28.57 24.49 32.65 18.37 39.7 12.24 48.98 23.10
7 # 1.01 Dalian G+25% sand+18%DHL+4%DCR 29.66 29.93 31.76 27.87 33.52 28.46 41.36 36.59
8 # 1.01 Dalian G+25% sand+18%DHL+5%DCR 32.65 32.84 32.65 28.57 36.73 30.50 46.94 42.60
The time-dependent variation in intensity curve that draws sample before and after the cement stone corrosion of different ingredients according to the resulting data of test as shown in Figure 1, 2, 3.
Intensity contrast table (150 ℃) before and after the different curing time cement corrosion of table 2
Numbering The 7d coefficient of corrosion inhibition Prescription 7d ultimate compression strength MPa 14d ultimate compression strength MPa 21d ultimate compression strength MPa 28d ultimate compression strength MPa
Not corrosion Corrosion Not corrosion Corrosion Not corrosion Corrosion Not corrosion Corrosion
1 # 0.89 Dalian G+35% sand 28.57 25.51 27.67 18.91 25.32 17.32 24.87 16.93
2 # 1.03 Dalian G+35% sand+5%DCR 36.85 38.02 35.61 35.11 34.53 30.49 34.16 30.61
3 # 1.02 Dalian G+35% sand+18%DHL+4%DCR 42.69 43.55 38.54 38.35 36.96 3582 36.92 32.74
4 # 1.02 Dalian G+35% sand+18%DHL+5%DCR 44.78 45.86 40.95 40.11 39.15 37.63 39.23 37.79
Intensity contrast table (60 ℃) before and after the different curing time cement corrosion of table 3
Numbering The 7d coefficient of corrosion inhibition Prescription 7d ultimate compression strength MPa 14d ultimate compression strength MPa 21d ultimate compression strength MPa 28d ultimate compression strength MPa
Not corrosion Corrosion Not corrosion Corrosion Not corrosion Corrosion Not corrosion Corrosion
1 # 0.93 The A class g cement 32.65 30.41 32.86 29.69 33.54 26.11 33.58 25.61
2 # 1.02 A class g cement+5%DCR 30.84 31.56 31.27 28.58 31.91 28.98 32.13 29.15
3 # 1.03 A class g cement+5%DCR+10%DSHJ 29.59 30.49 30.81 29.46 31.69 29.45 31.8 30.23
4 # 1.01 A class g cement+5%DCR+10%DSJ 32.76 32.99 33.63 31.83 33.75 30.88 33.98 31.03
From top experimental data and curve relation figure as can be seen, increase along with etching time, (after 7 days) ultimate compression strength all will decrease than the cement stone of uncorroded same system the later stage of cement stone sample at each temperature, just the amplitude difference that reduces of each individual system ultimate compression strength.Wherein the compression strength value of the corrosion of the cement system of adding preservative agent front and back does not change greatly, and the maximum range of decrease can reach more than the 10MPa.And adding preservative agent and the cement sample that adds water retaining simultaneously are less along with the amplitude that the increase ultimate compression strength of etching time reduces, and later strength is grown the requirement of strength that trend also satisfies cement mantle, and as seen the cement system of adding preservative agent and water retaining has increased antiseptic property really from intensity is grown upward.In addition, increase along with the sanitas dosage, the cement system antiseptic property strengthens, but shop experiment shows, when sanitas DCR dosage is higher than after 5%, the denseness of mortar architecture will sharply increase, mobile variation, such grout state can influence on-the-spot cementing operation operation, therefore, the sanitas dosage is limited in 5%.And when temperature is higher than more than 120 ℃,, improve silico-calcium than the effective technology means that are effective inhibition cement stone high temperature decline by adding a certain proportion of quartz sand.
Estimate the antiseptic property of cement system for convenience, we have defined a parameter, are used for representing the ratio of the ultimate compression strength of cement stone before and after the certain hour internal corrosion, are CO 2Coefficient of corrosion inhibition (see Table 1, table 2 and table 3).CO 2The corrosion strength of coefficient of corrosion inhibition=corrosion back intensity/not
From table in the data we also as can be seen, the coefficient of corrosion inhibition of cement system that adds sanitas is all greater than 1, this index has reached the requirement of opening the topic index.
Table 4 cement strength is with CO 2Dividing potential drop (P CO2) change list
Numbering Cement formula Ultimate compression strength, MPa Test temperature, ℃ Test period, d
P CO2＝1MPa P CO2＝1.5MPa P CO2＝2.5MPa P CO2＝5MPa
1 Dalian G+25% sand 18.78 18.19 17.43 16.32 120 28
2 Dalian G+25% sand+5%DCR 36.63 36.68 36.22 36.00 120 28
3 Dalian G+25% sand+10%DSJ 22.79 21.18 20.53 18.37 120 28
4 Dalian G+25% sand+5%DCR+10%DSJ 43.24 42.96 42.16 41.60 120 28
5 Dalian G+25% sand+18%DHL 29.31 26.42 25.65 23.10 120 28
6 Dalian G+25% sand+18%DHL+5%DCR 44.27 43.93 43.66 42.60 120 28
7 Dalian G+35% sand 22.72 20.12 17.57 16.93 150 28
8 Dalian G+35% sand+5%DCR 33.84 32.56 3134 30.61 150 28
9 Dalian G+35% sand+18%DHL+5%DCR 38.91 38.61 38.15 37.79 150 28
10 The A class g cement 26.89 26.32 25.83 25.61 60 28
11 A class g cement+5%DCR 30.05 29.77 29.39 29.15 60 28
12 A class g cement+5%DCR+6.5%DSHJ 31.26 30.87 30.64 30.23 60 28
13 A class g cement+5%DCR+10%DSJ 31.39 31.31 31.18 31.03 60 28
Simultaneously, again at corrosion of cement stone and CO 2Dividing potential drop (P CO2) between relation inquire into.Ultimate compression strength variation by cement stone can be seen (seeing Table 4), and whether adding preservative agent ultimate compression strength is all along with CO 2Dividing potential drop (P CO2) increase and descend, analyze reason and mainly be because along with the increase of pressure, CO 2Solubleness in water increases, and that is to say the CO in the water 2Concentration increases, and causes the acidity in the cement corrosion atmosphere to increase, thereby has accelerated corrosion.
Cement stone rate of permeation is with the Changing Pattern of etching time
Cement stone performance another one important evaluating index is exactly the rate of permeation of itself.Cement stone extent of corrosion also can be by being embodied in this index.Cement stone corrosion back rate of permeation sees Table 5 over time.
Table 5 cement stone sample corrosion back changes in permeability (120 ℃ of temperature)
Numbering Prescription The corrosion penetration rate (10 -3μ m 2) Corrosion back rate of permeation (10 -3μm 2)
3d 14d 28d 56d
1 # Dalian G+25% sand+5%DCR 0.093 0.120 0.146 0.185
2 # Dalian G+25% sand+10%DSJ 0.056 0.089 0.067 0.154
3 # Dalian G+25% sand 0.164 0.210 0.238 0.300
4 # Dalian G+25% sand+18%DHL 0.063 0.177 0.164 0.242
5 # Dalian G+35% sand+5%DCR 0.188 0.225 0.130 0.221
6 # Dalian G+55% sand+10%DHL+4%DCR 0.077 0.133 0.081 0.082
7 # Dalian G+25% sand+18%DHL+5%DCR 0.054 0.055 0.078 0.064
8 # Dalian G+25% sand+5%DCR+10%DSJ 0.088 0.097 0.113 0.083
Draw according to the resulting data of the test of table 58 kinds of prescriptions cement stone corrosion sample the time dependent curve relativity of rate of permeation as shown in Figure 4:
From the curve comparison diagram 4 of the experimental data of table 5 and rate of permeation, can draw, along with the increase of etching time, 1 #-8 #The rate of permeation of cement stone sample all will become greatly than the cement stone of uncorroded same system, is the amplitude difference that each individual system rate of permeation increases, and 1 #, 2 #, 3 #, 4 #, 5 #Cement sample is along with the increase rate of permeation of etching time has the trend of increase, and wherein 3 #The amplitude maximum that increases, it also is maximum that the rate of permeation in its later stage is compared with other mortar architecture, it is more serious that the rate of permeation after visible cement magma is corroded increases, and 6 #, 7 #, 8 #The rate of permeation of cement stone sample is along with the increase of etching time then changes not quite, and wherein 8 #The system rate of permeation is along with the increase rangeability minimum of etching time, and the permeability value in its later stage also is minimum.After adding sanitas and water retaining are described, strengthen the compactness of cement stone itself, increased CO 2Osmotic resistance.
Ultimate compression strength by cement stone sample before and after the corrosion and rate of permeation experimental data and curve relation figure can obtain following understanding:
1. uncorroded intensity all decreases under compressive strength rate the same terms of the cement stone sample after the corrosion, is the degree difference that each individual system intensity reduces, and the intensity later stage of each individual system is grown also difference of trend;
2. uncorroded rate of permeation all increases to some extent under permeability ratio the same terms of the cement stone sample after the corrosion;
3. the depth of corrosion of cement stone is relevant with the growth and the rate of permeation of the ultimate compression strength of cement stone, and under the identical etching condition, depth of corrosion is little, and then low, the ultimate compression strength of relative permeability reduces also fewly; Otherwise relative permeability height, ultimate compression strength reduce also manyly.
4. CO on intensity, rate of permeation 2More serious relatively to common neat slurry (high-density, low density systems) corrosion.
Description of drawings:
Fig. 1 is intensity contrast figure before and after 120 ℃ of cement mantle corrosion:
Fig. 2 is intensity contrast figure before and after 150 ℃ of cement corrosion:
Fig. 3 is intensity contrast figure before and after 60 ℃ of cement corrosion:
Fig. 4 is the permeability variation trend map of cement stone of respectively filling a prescription after the corrosion.
Embodiment:
Be further described below in conjunction with specific embodiment, this oil well is with preventing that the cement system of carbon dioxide corrosion from comprising following each component: following each component is gross weight proportioning by mass percentage in cement: 8～35% silica sand or quartz sand, 3～5% silicon-dioxide, 6.5～18% water retaining DSJ, DSHJ or DHL, cement.Wherein DSJ is by 75% N,N-DMAA, 5% sodium allylsulfonate, 20% N-vinyl pyrrolidone; DHL is that application number is the water retaining described in 03101262.0 application documents (styrene-butadiene latex molecular weight wherein is 5000～50000, and styrene-butadiene latex is the random polymerization of vinylbenzene and divinyl, and the value of x, y and z is 1000～1500); DSHJ is that application number is the water retaining described in 02157940.7 application documents; SILICA FUME is represented with DCR.
Be ground simulation test below:
By top comparative analysis experiment, we have established the cementing concrete protective system: sanitas DCR adds water retaining DHL, DSJ or DSHJ.Ultimate compression strength before and after the corrosion of this system changes little, and later strength is grown the requirement of strength that trend also satisfies cement mantle.In addition, this system rate of permeation is along with the increase rangeability of etching time is little, and is downward trend, so its preservative effect will be best.
In the above on the basis of shop experiment and evaluation study, for the compound degree of feasibility, the ground compounding cement paste performance in enormous quantities of verifying this cover cement protective system site operation and shop experiment and do the homogeneity of mixing, anticorrosion mortar architecture has been carried out ground simulation test, and again the ground compounding cement paste has been carried out indoor traditional performance composite testing, thereby can guarantee the feasibility and the validity of rig-site utilization.
Anti-CO 2Corrosion cement system scheme:
G class g cement+35% silica sand+5% inhibition weighting agent (DCR)+DSJ water retaining;
G class g cement+35% silica sand+5% inhibition weighting agent (DCR)+DHL water retaining.
The ground experiment program:
1) the ground simulation test cement slurry density is designed to 1.90g/cm 3, discharge capacity is by 1.4～1.6m 3/ min keeps continuously;
2) get the ground simulation test grout, carry out indoor composite testing, content of the test comprises point-to-point measurement cement slurry density and degree of mobilization, multiviscosisty test (93 ℃ * 51.7MPa and 135 ℃ * 82.7MPa), 48 hours compressive strength test (60 ℃ * 20.7MPa and 150 ℃ * 20.7MPa), API loss-of-coolant experiment (LOCE) (93 ℃ * 7MPa and 93 ℃ * 7MPa) and free liquid test.
3) anti-CO 2Corrosion cement system scheme: G class g cement+35% silica sand+5%DCR+DSJ water retaining.
The traditional performance that the on-the-spot grout of ground experiment reaches sees Table 6.
Table 6 mortar architecture traditional performance contrast table
Sequence number Free liquid ml Degree of mobilization cm Initial consistency BC Thickening time 93 ℃ * 51.7MPa min 93 ℃ * 7MPa of API dehydration ml 60 ℃ * normal pressure of 48h ultimate compression strength MPa
1 0.6 26 16 190 92 33.48
2 0.6 27 15 205 96 34.37
Annotate: sequence number 1 is the shop experiment data, and sequence number 2 is the ground simulation test data
See that from ground test result DSJ and protective system consistency are good, the cement slurry density of ground experiment is uniform and stable, and better mobile, shop experiment data and ground simulation test data are identical substantially, satisfy performance that site operation requires fully.Obtained as drawing a conclusion by ground experiment:
1, doing mixed back extra material mixes comparatively even, following grey stable.
2, the cement slurry density of ground experiment is uniform and stable, and is better mobile, satisfies performance that site operation requires fully.
3, the indoor composite performance of grout that is mixed of ground is better, and traditional performance can satisfy the cementing quality requirement.
4, ground experiment has reached its intended purposes, and anticorrosion mortar architecture can reach the site operation performance.
The rig-site utilization of corrosion-resistant cement slurry system:
Be the tame defensive wall rift volcanics lithologic gas reservoirs of overall evaluation Xu, quickening is in the whole arrangement of this structural belt, be total to 32 mouthfuls of well spacing since 2004, therefore the deep gas well of the tame defensive wall rift of Xu has become the most important thing of deep-well work from now on, guarantees that cementing quality also is a wherein vital link.
Because the needs of Daqing oil field exploitation, the exploitation of the geographic deep layer gas-bearing formation of tame defensive wall puts more effort slowly.But from the geographic hole condition of present Xu family defensive wall, more or less in the output gas all contains CO 2Gas.Maximum CO 2Gas content can reach more than 90%, and in November, 2002 Japan JFE company (Kawasaki Steel Corp) detects grand celebration oil pipe (the being equivalent to APIP110) sample that eight Xu Shen of factory, 1 Jing2000mChu takes out that recovers the oil, and the result shows CO has taken place 2Corrosion, depth of corrosion reaches 3mm about 1 month, be equivalent to that the local corrosion amount is about 36mm in 1 year.
So far be about to scrap less than 9 years and belong to the dark 2 well nineteen ninety-five brought in wells of Xu's tame defensive wall liter in the neighbourhood together, and the existing gas evolution in ground around the well head, analyzing reason also is owing to contain CO in this well Sweet natural gas 2(content 3-6.2%) causes thereby sleeve pipe has been produced corrosion failure.This this block down-hole of explanation grand celebration exists serious CO 2Corrosion, and depth of burial is dark, downhole temperature is high, CO 2The content height.
Simultaneously, CO 2Gas is having CO under water or the wet environment 2Not only can produce corrosion to sleeve pipe, and can produce heavy corrosion to hardened oilwell cement equally, its exercising result is: the basicity that has reduced cement stone, along with the increase of graphitic corrosion degree, the cementing properties component reduces in the cement stone, and it is big that rate of permeation becomes, ultimate compression strength reduces, even intensity completely loses, and loses the packing effect, simultaneously CO 2Cause telescopic corrosion, perforation or corrosion cracking from the outside surface immersion.
Therefore for the exploitation and the long term growth of the tame defensive wall deep layer gas-bearing formation of Xu, how to prevent CO effectively 2Corrosion in the life-span of prolongation oil gas well, is imminent.The tame defensive wall of grand celebration Xu area deep gas well basic condition sees Table 7.
The tame defensive wall of table 7 grand celebration Xu area deep gas well basic condition
Sequence number Pound sign Gas testing output * 10 4ml Daily output water m 3 Pressure MPa Temperature ℃ MTD m CO 2Content % Productive life year
1 Rise dark 2 32.6972 28.6 119.4 2801.8 3--6.2 9
2 Wang 903 5.0518 12.2154 32.911 123.3 3009.3 13.35
3 Rise dark 4 1.3865 94.91 33.25 121 3036.6
4 Virtue dark 6 13.8401 1.83 36.13 135.4 3280 7.472 3
5 Virtue dark 7 4.2361 36.44 137.8 3332.4 11.52
6 Virtue dark 801 4.1712 30.25 129 3088.3 1.874
7 Virtue dark 701 6.0682 11.2 38.18 140.6 3611.5 84.91
8 Virtue dark 9 5.0938 3 34.54 134.4 3345.2 93.083
9 Xu Shen 1 53.0057 38.85/3485.41 1576/4233.08 2.923
10 Rise dark 2-1 30.789 117 2.45 0.5
Through ground experiment; reached fully under the prerequisite that site operation requires at the cement slurry property of body series; a large amount of laboratory experiment data and curve have fully shown the practical feasibility of the anti-carbon dioxide corrosion of this cement system; the use of anticorrosion cement system has improved the intensity and the rate of permeation of cement stone under the wetting phase carbon dioxide environment greatly; slowed down the further corrosion of carbonic acid gas to a great extent to cementization; and then also played the protection tubing and casing and avoided the effect of corrosive component corrosive, thereby guaranteed to be rich in the ordinary production of carbonic acid gas oil gas well.
At present protective system DCR in the deep gas well of the tame defensive wall of Xu area, successfully finished Xu Shen 601, Xu Shen 2, risen dark 8, Xu Shen 3, Xu Shen 7, Xu Shen 8, Xu Shen 9, Xu Shen 401, Wang Shen 101, Xu Shen 502, risen dark 202, Xu Shen 801, risen the 2-17 well, Xu Shen 301, fragrant dark 101 and the test in place of more than ten mouthful of wells such as Xu Shen 10 wells, it is uniform and stable, also better with the cement additive workability to have guaranteed to tie up in the process of being mixed density at this cement slurry, has obtained ground construction effect (seeing Table 8) preferably.
Table 8 sanitas DCR is in the geographic experiment situation of the tame defensive wall of Xu
Sequence number Pound sign Well depth, m The well cementation date Bottom temperature, ℃ The sleeve pipe model One-level well cementation section, m Secondary well cementation section, m
Cement formula
1 Xu Shen 601 3705 2004.11.18 131 Tianjin P110 2250-3705 150-2250 Level: 25% quartz sand+6%DSHJ+5%DCR
2 Rise dark 202 3185 2004.11.20 122 Tianjin P110 2130-3185 150-2130 Level: 25% quartz sand+5%DCR+10%DSHJ
3 Rise dark 8 3714 2004.11.22 128 Tianjin TP110 2145-3714 150-2145 Level: 25% quartz sand+8%DCR+10%DSHJ
4 Xu Shen 7 4510 2004.12.11 160 Tianjin P110 3000-4510 150-3000 Level: 25% quartz sand+5%+18%DHL latex
5 Xu Shen 502 4361 2004.12.19 156 Tianjin P110 2000-4361 8% silica sand+3%DCR+18%DHL latex
6 Xu Shen 8 4228 2005.1.1 150 3Cr Tianjin P110 3347-4228 1350-3347 Level: 25% silica sand+5%DCR+18%DHL latex
Level: 8% silica sand+3%DCR+0.15%DQH-4
7 Xu Shen 9 4311 2005.1.8 152 3Cr Tianjin P110 2700-4311 150-2700 Level: 25% silica sand+5%DCR+18%DHL latex
Level: 8% silica sand+3%DCR+0.15%DQH-4
8 Xu Shen 3 4763.82 2005.1.14 165 3Cr Tianjin 3400-47638 2 150-3000 Level: 25% silica sand+5%DCR+18%DHL latex
Level: 8% silica sand+8%DCR+0.15%DQH-4
9 Xu Shen 401 4546 2005.1.11 159 3Cr Tianjin P110 3000-4546 150-2450 Level: 25% silica sand+5%DCR+18%DHL latex
Level: 8% silica sand+3%DCR+0.15%DQH-4
10 Xu Shen 101 3266.93 2005.1.29 114 3Cr Tianjin P110 2200-3266 150-2200 Level: 25% quartz sand+5%DCR+65%DSHJ
11 Xu Shen 801 4110 2005.7.18 139 3Cr Japan P110 2600-4110 0-2600 Level: 25% quartz sand+5%DCR+18%DHL latex
12 Rise dark 2-17 3150 2005.7.26 106.2 13Cr Japan and 3Cr Tianjin P110 2400-3150 100-2400 Level: 25% quartz sand+5%DCR+6.5%DSHJ
13 Virtue dark 101 3620 2005.9.11 122.7 3Cr Tianjin P110 3620-2200 2200-150 Level: 25% quartz sand+8%DCR+65%DSHJ
14 Xu Shen 301 4370 2005.9.16 156 3Cr Tianjin P110 2830-4370 0-2830 Level: 25% quartz sand+18%DHL latex+5%DCR
15 Xu Shen 10 4197.52 2005.9.29 143 13Cr Japan P110 3150-419 7.52 0-3150 Level: 25% quartz sand+18%DHL latex+5%DCR
The anti-CO of anticorrosive casing pipe and cement system 2The analysis of corrosion net effect:
CO 2Cause iron and steel general corrosion and serious local corrosion rapidly, make sleeve pipe and support equipment that early stage corrosion failure take place, and cause serious consequence.CO is being carried out in the LittleCreek oil field of the U.S. 2On-the-spot discovery of intensified oil reduction, do not taking to suppress CO 2The oil well casing of corrosion measure be corrosion failure less than 5 months, erosion rate is up to 12.7mm/a.The northern Personcille oil-gas field CO of Houston 2Content is up to 2.5%, and the use of N80 sleeve pipe was a corrosion failure less than 1 year, and erosion rate is 5.6mm/a.China is some oil field CO of the main force quite 2Content is very high, and North China Oilfield, long celebrating oil field, Jilin Oil Field etc. all occur because of CO 2Corrosion causes oil well to be scrapped, and causes the enormous economic loss accident.Oil field, Tarim Basin LN204 well P105 oil pipe only uses 21 months because CO 2Corrosion and fall well.The Zhongyuan Oil Field is since nineteen ninety-five, just because of CO 2Corrosion and cause 10 mouthfuls of wells 17 times that tubing string perforation and break-off accident take place.The oil pipe CO that take out at 2000 meters of grand celebration Xu Shen 1 well 2Seriously corroded, a year local corrosion amount is about 36mm, less than getting final product corrosion failure half a year.Desk research shows that CO is arranged 2The life-span of corrosive well generally can be above 10 years.Rising dark 2 wells puts into production less than 9 years just because CO 2A seriously corroded and to have to scrap be exactly a good illustration.
By shop experiment evaluation and analysis-by-synthesis, adopt the chrome-bearing alloy Steel Sleeve exactly for the measure that this corrosion is best.Adopt anti-corrosion alloy sleeve pipe (containing chromium) the year etching extent of down-hole casing can be reduced to below the 0.125mm, and keep other mechanical property constant, this just means 5 1/ 2" sand string is if casing wall thickness is pressed 7.76mm, because CO 2Corrosive pitting feature, then by this erosion rate then the sleeve pipe of chromium content 13% or more need 61 years ability to produce corrosion failure, and general conventional deep-well owing to down-hole geologic agent, underground water and the composition that contained thereof (as Cl -, H +, Ca 2+, Mg 2+Deng) also can be to factors such as ordinary casing steel corrosions, therefore the mean lifetime of conventional deep-well generally should be about 30 ~ 50 years.This shows, adopt the Chrome metal powder sleeve pipe can effectively prolong the life-span of well, keep good down-hole oil gas extraction environment.
Simultaneously, because CO 2Can produce heavy corrosion to the oil well cement ring equally, consequently: reduced the basicity of cement stone, along with the increase of graphitic corrosion degree, the cementing properties component reduces in the cement stone, and it is big that rate of permeation becomes, and ultimate compression strength reduces, even intensity fails fully.Therefore for CO is arranged 2The well of gas must add anti-corrosion composition in cement, improve the density and the erosion resistance of cement mantle, guarantees the packing effect of cement mantle.
From salient features ultimate compression strength and this two aspect of rate of permeation of cement stone, but the ultimate compression strength of anticorrosion cement stone more than 28 days proof strength do not fail, rate of permeation does not increase, and with do not have CO 2Corrosive cement stone performance is suitable, even the also slightly enhancing of some performance, as the aspects such as stability of high temperature resistance, impermeability and cement slurry.Moreover, by scanning electron microscope analysis and X-diffraction analysis, can determine that from the microcosmic of cement stone and on the hydrated product on the internal structure of anticorrosion cement system all be quite stable, and the intensity of cement stone grows basically that itself intensity grows fully more than 20 days more than 90%.Therefore, can conclude, can reach anti-CO under the high-temperature and high-pressure conditions of anticorrosion cement system down-hole fully 2The corrosive effect.

Claims (2)

1, a kind of oil well cement system that prevents carbon dioxide corrosion, it is characterized in that: comprise following each component: following each component is gross weight proportioning by mass percentage in cement: 8～35% silica sand or quartz sand, 5～8% SILICA FUME, 6.5～18% water retaining DSJ, DSHJ or DHL, cement.
2, the oil well according to claim 1 cement system that prevents carbon dioxide corrosion, it is characterized in that: DSJ is by 75% N,N-DMAA, 5% sodium allylsulfonate, 20% N-vinyl pyrrolidone.
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CN102585788A (en) * 2012-01-20 2012-07-18 长江大学 Supersaturated sodium chloride cement slurry system for well cementation
CN103571444A (en) * 2012-07-20 2014-02-12 中国石油化工股份有限公司 High temperature-resistant oil well cement additive, and preparation and applications thereof
CN105254227A (en) * 2015-10-01 2016-01-20 中国石油集团西部钻探工程有限公司 Heat preservation cement paste and preparation method thereof
CN105295875A (en) * 2015-10-01 2016-02-03 中国石油集团西部钻探工程有限公司 Heat insulation cement paste and preparation method thereof
CN115043621A (en) * 2022-03-29 2022-09-13 中海石油(中国)有限公司深圳分公司 High-density cement slurry resistant to high temperature and carbon dioxide corrosion and preparation method and application thereof
CN115677282A (en) * 2021-07-29 2023-02-03 中国地质大学（北京） Well cementation cement slurry suitable for carbon dioxide flooding oil well and application thereof

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102585788A (en) * 2012-01-20 2012-07-18 长江大学 Supersaturated sodium chloride cement slurry system for well cementation
CN102585788B (en) * 2012-01-20 2013-07-31 长江大学 Supersaturated sodium chloride cement slurry system for well cementation
CN103571444A (en) * 2012-07-20 2014-02-12 中国石油化工股份有限公司 High temperature-resistant oil well cement additive, and preparation and applications thereof
CN105254227A (en) * 2015-10-01 2016-01-20 中国石油集团西部钻探工程有限公司 Heat preservation cement paste and preparation method thereof
CN105295875A (en) * 2015-10-01 2016-02-03 中国石油集团西部钻探工程有限公司 Heat insulation cement paste and preparation method thereof
CN115677282A (en) * 2021-07-29 2023-02-03 中国地质大学（北京） Well cementation cement slurry suitable for carbon dioxide flooding oil well and application thereof
CN115043621A (en) * 2022-03-29 2022-09-13 中海石油(中国)有限公司深圳分公司 High-density cement slurry resistant to high temperature and carbon dioxide corrosion and preparation method and application thereof

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