CN111394073B - High-temperature-resistant oil testing oil-based well completion fluid and preparation method and application thereof - Google Patents
High-temperature-resistant oil testing oil-based well completion fluid and preparation method and application thereof Download PDFInfo
- Publication number
- CN111394073B CN111394073B CN202010193214.0A CN202010193214A CN111394073B CN 111394073 B CN111394073 B CN 111394073B CN 202010193214 A CN202010193214 A CN 202010193214A CN 111394073 B CN111394073 B CN 111394073B
- Authority
- CN
- China
- Prior art keywords
- oil
- emulsifier
- temperature
- temperature resistant
- fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/32—Non-aqueous well-drilling compositions, e.g. oil-based
- C09K8/36—Water-in-oil emulsions
Landscapes
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Lubricants (AREA)
- Machines For Laying And Maintaining Railways (AREA)
Abstract
The invention relates to a high-temperature-resistant oil testing oil-based well completion fluid, a preparation method and application thereofEmulsifier, high-temperature resistant auxiliary emulsifier, filtrate reducer, calcium oxide, calcium chloride salt water and weighting agent. The density of the oil-based completion fluid is 1.60g/cm3～2.10g/cm3Standing at a constant temperature of 200 ℃ for 15 days, wherein ES is more than 1500V, SSI is less than 0.20, probing the bottom by using a glass rod, clearly hearing the sound of the glass rod touching the bottom, rapidly approaching the cup wall, and having excellent high-temperature emulsification stability and sedimentation stability, wherein barite has no precipitation phenomenon. Compared with water-based well completion fluid, the invention has the advantages of simple field process, low cost, oil-gas layer protection and the like.
Description
Technical Field
The invention belongs to the technical field of oil and gas field exploitation, and particularly relates to a high-temperature-resistant oil testing oil-based well completion fluid, and a preparation method and application thereof.
Background
With the development of oil drilling to deep wells and ultra-deep wells, the drilling conditions and well body structures are more and more complex, and high temperature, high pressure and eye ointment formations are increased. In order to meet the requirement of high-difficulty drilling of three-high oil-gas wells, oil-based drilling fluid is generally adopted for drilling at home and abroad at present, and then oil testing and well completion operations are carried out. In the process of drilling the deep well, the underground temperature is high, the well body structure is complex, the oil testing period is long, the high-temperature and high-pressure well oil testing process is complex, the lower well completion pipe column period is long, the process requirement is high, and the requirement on the oil testing completion fluid is higher. The main technical difficulty is that the test oil completion fluid is kept stand at high temperature for a long time, the system performance is deteriorated, weighting agent sedimentation is easily generated, the lower pipe column is difficult to block or pump, and higher technical risk exists. The sedimentation stability, the rock carrying capacity and other important indexes of the packer are deteriorated, complex conditions such as blockage of a test pipe column, failure of a test tool, difficulty in setting or unsetting of the packer and the like are caused, the non-production time efficiency is increased, the reservoir protection is not facilitated, even frequent underground accidents are caused, and the development efficiency of an oil and gas field is seriously influenced.
The prior inventions related to the well completion fluid are few, and most conventional wells directly adopt a brine system to carry out oil testing well completion operation. Aiming at the oil testing and well completion operation of a high-temperature well, a Chinese patent with the publication number of 103160259A and the publication number of 2018, 11 and 30 discloses a long-acting stable water-based completion fluid and a preparation method thereof, and the long-acting stable water-based completion fluid still has good rheological property, low filtration loss and excellent high-temperature-resistant long-acting sedimentation stability after being kept at a constant temperature of 200 ℃ for 30 days, and is compared with a common solid-free brine completion fluid system under the ultrahigh-temperature condition.
When the water-based completion fluid is used for oil-based oil testing and well completion operation, the water-based completion fluid and the oil-based drilling fluid are polluted in a large area in the displacement process, so that the cost of the drilling fluid is increased; meanwhile, high-viscosity isolation liquid needs to be injected into the contact surface, the high-temperature resistance of the isolation liquid, the compatibility with water-based completion fluid and oil-based drilling fluid, the displacement efficiency and the like need to be considered, the field operation risk is increased, and the operation period is delayed.
The oil-based drilling fluid is in a circulating dynamic working condition and bears high temperature for a relatively short time during operation, while the completion fluid is in a static working condition and bears the high temperature for 10-15 days in a static state. Therefore, the existing oil-based drilling fluid cannot be directly used as a completion fluid under a high-temperature condition, has the problems of high-temperature demulsification, high-temperature degradation of a treating agent, barite precipitation and the like, and cannot meet the requirements of oil testing and well completion operations.
Disclosure of Invention
In view of the above, the main object of the present invention is to provide a high temperature resistant test oil-based completion fluid, and a preparation method and an application thereof, wherein the system has good emulsion stability and sedimentation stability at high temperature, and ensures that the oil-based test oil-based completion fluid has good stability after standing at 200 ℃ for 15 days, and the weighting agent does not precipitate, so as to meet the requirements of high temperature test oil completion operation.
In order to achieve the purpose, the invention provides a high-temperature-resistant oil-based completion fluid which comprises the following components in percentage by weight:
the balance of base oil and calcium chloride brine with the concentration of 20-30 wt%, and the volume ratio of the base oil to the calcium chloride brine is 80: 20-90: 10.
Further, the organic clay is lipophilic clay formed by processing bentonite with quaternary ammonium salt surfactant.
Further wherein the organoclay is prepared by the steps of:
adding sodium carbonate into bentonite, and heating in water bath at 70-80 deg.C for 3 hr to obtain sodium bentonite; adding quaternary ammonium salt cationic surfactant, heating in water bath at 70-80 deg.C for 2h, drying at 105 deg.C to constant weight, and sieving with 200 mesh sieve to obtain the organic soil; the bentonite, the sodium carbonate and the quaternary ammonium salt cationic surfactant are in a weight ratio of 6: 1: 2.
further wherein the quaternary ammonium salt is selected from at least one of dodecyltrimethylammonium bromide, hexadecyldimethylammonium chloride and dodecyldimethylbenzylammonium chloride.
Further, the high-temperature resistant main emulsifier is prepared from (1.5-2.5) by weight: (0.8-1.2): 1 of emulsifier A, emulsifier B and emulsifier C.
Further, the emulsifier A is an alkyl alcohol polyoxyethylene ether nonionic surfactant; the emulsifier B is sulfonate; the emulsifier C is selected from stearate.
Further, the emulsifier A is C10-18 fatty alcohol-polyoxyethylene ether, and the polymerization degree n is 1-5; the emulsifier B is at least one selected from the group consisting of iron petroleum sulfonate, sodium alkyl aryl sulfonate and sodium alkyl succinate sulfonate.
Further, the stearate is zinc stearate or sodium stearate.
Further, the high-temperature resistant auxiliary emulsifier is prepared by mixing polyoxyethylene diene dioleate with an HLB value of 7-8 and polyoxypropylene stearate with an HLB value of 7-9 according to a weight ratio of 1: 1-3 by weight ratio.
Further wherein the first fluid loss additive is selected from at least one of organo-lignite, oxidised bitumen and emulsified bitumen.
Further wherein the second fluid loss additive is a polymeric fluid loss additive.
Further wherein the second fluid loss additive is prepared by the steps of:
under the magnetic stirring condition of 500-; then adding 4g of dispersant under the protection of nitrogen; after the monomer is completely dissolved, adding 15-30 g of monomer and 0.8g of initiator, fully dissolving, reacting for 5 hours in a constant-temperature water bath at 65 ℃, and adding 2g of cross-linking agent every 30min in the reaction process; and after the reaction is finished, cooling to room temperature, washing for 3-4 times by using absolute ethyl alcohol, centrifuging for 10min at the rotating speed of 3000r/min, then carrying out vacuum drying on the obtained product at the temperature of 50 ℃ for 24h, and grinding into powder of 40-60 meshes to obtain the polymer fluid loss additive.
Further, the weight ratio of the monomers is 1: (1-3) acrylamide and butyl acrylate; the initiator is azobisisobutyronitrile or potassium persulfate; the dispersing agent is sodium dodecyl sulfate; the crosslinking agent is divinylbenzene.
Further, the weighting agent is barite, and the density of the barite is more than or equal to 4.35g/cm3D50 is less than or equal to 2 mu m; the base oil is selected from diesel, white oil or synthetic base oil.
In order to achieve the above object, the present invention provides a method for preparing the high temperature resistant test oil based completion fluid, comprising the following steps in sequence:
1) under the condition of high-speed stirring, adding organic soil into base oil according to a certain proportion, stirring for 5-10min to make it fully and uniformly stirred;
2) adding calcium oxide, a high-temperature-resistant main emulsifier, a high-temperature-resistant auxiliary emulsifier, a first filtrate reducer, a second filtrate reducer and a weighting agent into the base slurry obtained in the step 1) in proportion, and respectively stirring at a high speed for 5-10min to dissolve or uniformly disperse the calcium oxide, the high-temperature-resistant main emulsifier, the high-temperature-resistant auxiliary emulsifier, the first filtrate reducer, the second filtrate reducer and the weighting agent; wherein, calcium chloride brine is added after the high temperature resistant auxiliary emulsifier is added and before the first filtrate reducer is added, and the mixture is stirred at a high speed for 10 to 20 min;
3) adding weighting agent into the glue solution obtained in the step 2) according to a proportion, and stirring at a high speed for 10-20min to ensure that the density of the glue solution reaches 1.60g/cm3～2.10g/cm3；
4) Stirring the semi-finished completion fluid obtained in the step 3) at a high speed for 2-3h, and fully shearing to obtain the high-temperature oil-based oil testing completion fluid.
Further, in the step 2), the calcium oxide, the high-temperature resistant main emulsifier, the high-temperature resistant auxiliary emulsifier, the calcium chloride brine, the first fluid loss additive and the second fluid loss additive which are sequentially added into the base slurry are the next components after being dissolved or uniformly dispersed.
Further, in the steps 1) to 4), the high-speed stirring speed is 11000 to 12000 r/min.
In order to achieve the purpose, the invention provides an application of the high-temperature-resistant oil-testing oil-based completion fluid in oil-based oil-testing completion operation at the temperature of more than 200 ℃.
The invention has the following beneficial effects:
the high-temperature-resistant oil testing oil-based completion fluid provided by the invention is used for oil testing and completion operations after the oil-based drilling fluid drills. The completion fluid comprises base oil, organic soil, emulsifiers (a high-temperature resistant main emulsifier and a high-temperature resistant auxiliary emulsifier), a fluid loss additive, calcium oxide, calcium chloride brine and a weighting agent. The density of the completion fluid is 1.60g/cm3～2.10g/cm3Standing at 200 deg.C for 15 days with ES > 1500V and SSI < 0.20, and the well completion fluid has good emulsion stability, sedimentation stability and rheological property; the completion fluid is evaluated by a rod dropping method, the sound of touching the bottom of a glass rod can be clearly heard, the glass rod is quickly close to the wall of a cup, the bottom of the glass rod does not have hard precipitation, the phenomenon of barite sedimentation is avoided, and the completion fluid has excellent emulsion stability and sedimentation stability; the completion fluid is evaluated by adopting a static Stable Stratification Index (SSI) method, wherein SSI is less than 0.20. The temperature resistance of the oil-based well testing fluid reaches 200 ℃, the problem of high-temperature sedimentation of the existing oil-based well testing fluid is solved, and the oil-based well testing fluid has many advantages compared with a water-based well testing fluid: the field process is simple, a conversion system is not needed, and the construction period is not delayed; can be recycled, has good protection effect on oil and gas layers, particularly water-sensitive strata, and improves the development efficiency of oil and gas fields.
Detailed Description
To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description will be given to the specific implementation, structure, characteristics and effects of the high temperature resistant test oil-based completion fluid and the preparation method thereof according to the present invention, in combination with the preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
The following percentages, unless otherwise specified, are weight volume percentages.
The following materials, unless otherwise specified, are all commercially available.
Example 1 this example provides a density of 1.60g/cm3High temperature oil base test oil completion fluid (1 m)3System) comprising the following components in percentage by weight by volume: 3% of organic soil; 3.5 percent of high-temperature resistant main emulsifier; 3% of high-temperature resistant auxiliary emulsifier; 4% of calcium oxide; 4% of a first fluid loss additive (organic lignite); 1% of a second filtrate reducer; a synthetic base oil and a calcium chloride brine at a concentration of 20wt% (v/v) in a volume ratio of 80: 20; the balance of barite (the density is more than or equal to 4.35 g/cm)3、D50≤2μm)。
The preparation method of the high-temperature oil-based oil testing completion fluid sequentially comprises the following steps of:
1) under the condition of high-speed stirring at 11000r/min, adding the organic soil into the synthetic base oil according to the proportion, and stirring for 5min to fully and uniformly stir the organic soil;
2) sequentially adding calcium oxide, a high-temperature-resistant main emulsifier, a high-temperature-resistant auxiliary emulsifier, a first fluid loss agent, a second fluid loss agent and a weighting agent into the base slurry obtained in the step 1) in proportion, and respectively stirring at a high speed for 5min to dissolve or disperse the materials uniformly; wherein, calcium chloride brine is added after the high temperature resistant auxiliary emulsifier is added and before the first filtrate reducer is added, and the mixture is stirred at a high speed for 10 min;
3) adding a weighting agent into the glue solution obtained in the step 2) according to a proportion, and stirring at a high speed for 20min to ensure that the density of the glue solution reaches 1.60g/cm3；
4) Stirring the semi-finished completion fluid obtained in the step 3) at a high speed for 2 hours to fully shear the semi-finished completion fluid to obtain the high-temperature oil-based oil-testing completion fluid.
The organic soil is prepared by the following steps:
adding sodium carbonate into bentonite, and heating in water bath at 70-80 deg.C for 3 hr to obtain sodium bentonite; adding quaternary ammonium salt cationic surfactant, heating in water bath at 70-80 deg.C for 2h, drying at 105 deg.C to constant weight, and sieving with 200 mesh sieve to obtain the organic soil; the bentonite, the sodium carbonate and the quaternary ammonium salt cationic surfactant (dodecyl dimethyl benzyl ammonium chloride) are mixed according to the weight ratio of 6: 1: 2.
the second fluid loss additive is prepared by the following steps:
under the magnetic stirring condition of 500-; then adding 4g of dispersant under the protection of nitrogen; after the monomer and the initiator are completely dissolved, adding 20g of the monomer and 0.8g of the initiator, reacting for 5 hours in a constant-temperature water bath at 65 ℃ after the monomer and the initiator are completely dissolved, and adding 2g of the cross-linking agent every 30min in the reaction process; and after the reaction is finished, cooling to room temperature, washing for 3-4 times by using absolute ethyl alcohol, centrifuging for 10min at the rotating speed of 3000r/min, then carrying out vacuum drying on the obtained product at the temperature of 50 ℃ for 24h, and grinding into powder of 40-60 meshes to obtain the polymer fluid loss additive. The weight ratio of the monomers is 1: 3 acrylamide and butyl acrylate; the initiator is azobisisobutyronitrile; the dispersing agent is sodium dodecyl sulfate; the crosslinking agent is divinylbenzene.
Example 2 this example provides a density of 1.90g/cm3The high-temperature oil-based well testing and completion fluid of (1 m)3System) comprising the following components in percentage by weight by volume: 2.5 percent of organic soil; 2% of high-temperature resistant main emulsifier; 4% of high-temperature resistant auxiliary emulsifier; 3% of calcium oxide; 3% of a first fluid loss additive (emulsified asphalt); 1.5 percent of second filtrate reducer; diesel oil and 25 wt% calcium chloride brine with volume ratio of 85: 15; the balance of barite (the density is more than or equal to 4.35 g/cm)3、D50≤2μm)。
The preparation method of the high-temperature oil-based oil testing completion fluid sequentially comprises the following steps of:
1) under the condition of high-speed stirring at 11000r/min, adding the organic soil into the diesel oil according to the proportion, and stirring for 5min to fully and uniformly stir the mixture;
2) sequentially adding calcium oxide, a high-temperature resistant main emulsifier, a high-temperature resistant auxiliary emulsifier, a first filtrate reducer, a second filtrate reducer and a weighting agent into the base slurry obtained in the step 1) according to a proportion, and respectively stirring at a high speed for 5min to dissolve or uniformly disperse the calcium oxide, the high-temperature resistant main emulsifier, the high-temperature resistant auxiliary emulsifier, the first filtrate reducer, the second filtrate reducer and the weighting agent; wherein, calcium chloride brine is added after the high temperature resistant auxiliary emulsifier is added and before the first filtrate reducer is added, and the mixture is stirred at a high speed for 10 min;
3) adding weighting agent into the glue solution obtained in the step 2) according to the proportion, and stirring at high speed for 20min to ensure that the density of the glue solution reaches 1.90g/cm3；
4) And 3) stirring the semi-finished product of the completion fluid obtained in the step 3) at a high speed for 3 hours to fully shear the semi-finished product of the completion fluid, so as to obtain the high-temperature oil-based oil testing completion fluid.
The organic soil is prepared by the following steps:
adding sodium carbonate into bentonite, and heating in water bath at 70-80 deg.C for 3 hr to obtain sodium bentonite; adding a quaternary ammonium salt cationic surfactant, heating in a water bath at 70-80 ℃ for 2h, drying at 105 ℃ to constant weight, and sieving with a 200-mesh sieve to obtain the organic soil; the bentonite, the sodium carbonate and the quaternary ammonium salt cationic surfactant (cetyl dimethyl ammonium chloride) are in a weight ratio of 6: 1: 2.
the second fluid loss additive is prepared by the following steps:
under the magnetic stirring condition of 500-; then adding 4g of dispersant under the protection of nitrogen; after the monomer and the initiator are completely dissolved, adding 20g of the monomer and 0.8g of the initiator, reacting for 5 hours in a constant-temperature water bath at 65 ℃ after the monomer and the initiator are completely dissolved, and adding 2g of the cross-linking agent every 30min in the reaction process; and after the reaction is finished, cooling to room temperature, washing for 3-4 times by using absolute ethyl alcohol, centrifuging for 10min at the rotating speed of 3000r/min, then carrying out vacuum drying on the obtained product at the temperature of 50 ℃ for 24h, and grinding into powder of 40-60 meshes to obtain the polymer fluid loss additive. The weight ratio of the monomers is 1: 3 acrylamide and butyl acrylate; the initiator is azobisisobutyronitrile; the dispersing agent is sodium dodecyl sulfate; the crosslinking agent is divinylbenzene.
Example 3 this example provides a density of 2.10g/cm3The high-temperature oil-based oil testing completion fluid (1 m)3System) comprising the following components in percentage by weight volume: 1.5 percent of organic soil; 2% of high temperature resistant main emulsifier; 2% of high-temperature resistant auxiliary emulsifier; 2% of calcium oxide; 2% of a first fluid loss additive (oxidized asphalt); 3% of a second filtrate reducer; diesel oil and 30% (v/v) calcium chloride brine with the volume ratio of 90: 10; the balance of barite (the density is more than or equal to 4.35 g/cm)3、D50≤2μm)。
The preparation method of the high-temperature oil-based oil testing completion fluid sequentially comprises the following steps of:
1) under the condition of high-speed stirring at 12000r/min, adding the organic soil into the diesel oil according to the proportion, and stirring for 5min to ensure that the mixture is fully and uniformly stirred;
2) sequentially adding calcium oxide, a high-temperature-resistant main emulsifier, a high-temperature-resistant auxiliary emulsifier, a first filtrate reducer, a second filtrate reducer and a weighting agent into the base slurry obtained in the step 1) in proportion, and respectively stirring at a high speed for 5min to dissolve or uniformly disperse the calcium oxide, the high-temperature-resistant main emulsifier, the high-temperature-resistant auxiliary emulsifier, the first filtrate reducer, the second filtrate reducer and the weighting agent; wherein, calcium chloride brine is added after the high temperature resistant auxiliary emulsifier is added and before the first filtrate reducer is added, and the mixture is stirred at a high speed for 20 min;
3) adding weighting agent into the glue solution obtained in the step 2) according to the proportion, and stirring at high speed for 20min to ensure that the density of the glue solution reaches 2.10g/cm3；
4) And 3) stirring the semi-finished product of the completion fluid obtained in the step 3) at a high speed for 2 hours, and fully shearing the semi-finished product to obtain the high-temperature oil-based oil testing completion fluid.
The organic soil is prepared by the following steps:
adding sodium carbonate into bentonite, and heating in water bath at 70-80 deg.C for 3 hr to obtain sodium bentonite; adding quaternary ammonium salt cationic surfactant, heating in water bath at 70-80 deg.C for 2h, drying at 105 deg.C to constant weight, and sieving with 200 mesh sieve to obtain the organic soil; the bentonite, the sodium carbonate and the quaternary ammonium salt cationic surfactant (cetyl dimethyl ammonium chloride) are in a weight ratio of 6: 1: 2.
the second fluid loss additive is prepared by the following steps:
under the magnetic stirring condition of 500-; then adding 4g of dispersant under the protection of nitrogen; after the monomer and the initiator are completely dissolved, adding 30g of the monomer and 0.8g of the initiator, reacting for 5 hours in a constant-temperature water bath at 65 ℃ after the monomer and the initiator are completely dissolved, and adding 2g of the cross-linking agent every 30min in the reaction process; and after the reaction is finished, cooling to room temperature, washing for 3-4 times by using absolute ethyl alcohol, centrifuging for 10min at the rotating speed of 3000r/min, then carrying out vacuum drying on the obtained product at the temperature of 50 ℃ for 24h, and grinding into powder of 40-60 meshes to obtain the polymer fluid loss additive. The weight ratio of the monomers is 1: 3 acrylamide and butyl acrylate; the initiator is potassium persulfate; the dispersing agent is sodium dodecyl sulfate; the crosslinking agent is divinylbenzene.
The specific composition and ratio of the high temperature resistant primary emulsifier and the high temperature resistant secondary emulsifier described in the above examples 2 and 3 are the same as those of example 1.
Comparative example 1 this comparative example provides a high temperature oil based test completion fluid having substantially the same composition and preparation steps as example 2, except that: comparative example 1 no second fluid loss additive was added.
Comparative example 2 this comparative example provides a high temperature oil-based test completion fluid having substantially the same composition as example 3, except that: the comparison example 2 is added with common barite, namely the barite D50 is between 20 and 30 mu m, and the example 3 is added with barite (the density is more than or equal to 4.35 g/cm)3、 D50≤2μm)。
Comparative example 3 this comparative example is an oil-based drilling fluid at the site of a well in a Tarim oilfield having a density of 1.90g/c m3The oil-based drilling fluid comprises the following components in percentage by mass and volume: 2.5% organic soil + 4% calcium oxide + 2.5% primary emulsifier VERSAMUL + 3% co-emulsifier VERSACOAT + VERSAGEL-HT + 3% fluid loss additive VERSATROL-HT (the primary emulsifier, the co-emulsifier, the organic soil and the fluid loss additive are all purchased from mikabat mud of south china seas) + diesel oil and 25 wt% calcium chloride brine (the oil-water ratio of the two is 85:15(v/v)) + normal barite (D50 between 20 and 30 μm).
The preparation method of the on-site oil-based drilling fluid sequentially comprises the following steps of:
1) under the condition of high-speed stirring at 12000r/min, adding the organic soil into the diesel oil according to the proportion, and stirring for 5min to fully and uniformly stir the mixture;
2) sequentially adding calcium oxide, a main emulsifier, an auxiliary emulsifier, a filtrate reducer and barite into the base slurry obtained in the step 1) according to a proportion, and respectively stirring at a high speed for 5min to dissolve or uniformly disperse the calcium oxide, the main emulsifier, the auxiliary emulsifier, the filtrate reducer and the barite; wherein, calcium chloride brine is added after the auxiliary emulsifier is added and before the filtrate reducer is added, and the mixture is stirred at a high speed for 10 min;
3) adding common barite into the glue solution obtained in the step 2) in proportion, and stirring at high speed for 20min to make the density reach 1.90g/cm3；
4) Stirring the semi-finished completion fluid obtained in the step 3) at a high speed for 2h to fully shear the semi-finished completion fluid to obtain the on-site oil-based drilling fluid.
The high temperature resistant main emulsifiers used in the formulations of examples 1-3 and comparative examples 1-2 above were: fatty alcohol-polyoxyethylene ether (polymerization degree n is 5, C atom number is 16), alkyl succinate sodium sulfonate and zinc stearate are mixed according to the weight ratio of 1.5:1:1 to obtain the product; the high-temperature resistant auxiliary emulsifier comprises: the mixture of a polyoxyethylene dioleate having an HLB value of 7.5 and a polyoxypropylene stearate having an HLB value of 8 was prepared at a weight ratio of 1: 2.
The above examples 1-3 and comparative examples 1-3 were added in the order of formulation and sufficiently sheared with high speed stirring to obtain high temperature oil based well testing fluids examples 1, 2 and 3 and high temperature oil based well testing fluids comparative examples 1, 2 and 3.
High temperature rheology and emulsion stability tests. The 3 examples and 3 comparative examples were respectively roll aged at 200 ℃ for 16h, and performance tests before and after roll aging were performed according to the oil-based drilling fluid test procedure (GB/T16783.2-2012), and the test results are shown in Table 1.
TABLE 1 comparison of rheological and emulsion stability of high temperature oil-based test completion fluids
As can be seen from Table 1, the viscosity, static shear force and dynamic shear force of examples 1-3 of the present invention all increased with increasing density after rolling aging at a high temperature of 200 ℃, but the values of the viscous shear were moderate and the ES exceeded 2000V. The high-temperature oil-based oil testing completion fluid has good rheological property and emulsion stability, and is ensured not to settle after being stood at high temperature for a long time. Comparing comparative example 1 without the second fluid loss additive with example 2, the completion fluid of comparative example 1 has lower shearing force and ES after aging, which is not enough to maintain high-temperature emulsion stability and sedimentation stability; the second fluid loss additive of the embodiment 2 is a polymer fluid loss additive, which is not easy to degrade at high temperature and is beneficial to high-temperature stability; comparison of comparative example 2 and example 3 without the addition of barite of D50 ≦ 2 μm shows that the smaller the particle size of barite of D50 ≦ 2 μm, the greater the viscosity effect and the greater the viscosity and shear force. Comparing comparative example 3 with example 2, it can be seen that the dynamic shear force, static shear force and ES of the oil-based drilling fluid of comparative example 3 are all smaller than those of example 3, indicating that the high temperature rheology and emulsion stability of the system are inferior to those of example 2.
And (4) testing the high-temperature sedimentation stability. After 3 examples and 3 comparative examples were left standing at 200 ℃ for 7 days, 10 days and 15 days, respectively, the bottom was probed with a glass rod, and the experimental phenomenon was recorded. And testing the layering index by using a static layering index method. The Static layering Index method is a method for quantitatively and qualitatively evaluating the Static sedimentation stability of drilling and completing fluid, firstly, the drilling and completing fluid is stood for a set time at a specific temperature in a closed container, then, the free fluid and the average density of each layer of the drilling and completing fluid are tested, and the Static layering Index (Static Stratification Index) is calculated by a formula (1), namely an SSI value, wherein the larger the value is, the more serious the solid phase sedimentation is, the worse the sedimentation stability is, and otherwise, the better the sedimentation stability of the drilling and completing fluid is. The detection result of the method can visually reflect the deviation degree of the density redistribution formed by the sedimentation of the drilling completion fluid and the density before sedimentation, and the SSI value can judge the static sedimentation degree of the drilling completion fluid.
Wherein: v% ofi-the volume fraction, percentage, of each layer in the aging tank;
ΔMWi-the density difference, g/cm, between each layer of completion fluid and the initial completion fluid3；
The test results are shown in Table 2.
TABLE 2 high temperature oil based test run completion fluid settling stability comparison
As can be seen from Table 2, after standing at a high temperature of 200 ℃ for 15 days in the examples 1 to 3 of the invention, the materials can freely reach the bottom and lean to the side by evaluation of a rod dropping method, and the bottom does not have hard precipitates; the static stratification index values SSI are all less than 0.20, which indicates that the oil-based test oil completion fluids of examples 1-3 of the present invention do not settle after standing at high temperature for a long time. Comparing comparative example 1 without the second fluid loss additive with example 2, the completion fluid of comparative example 1 can not satisfy the condition of no sedimentation in long-time downhole operation at 200 ℃ after standing for 15 days. While the polymeric fluid loss additive of example 2 enhances the high temperature stability of the system. As can be seen from comparison between comparative example 2 and example 3, in which no barite with a particle size of 2 μm or less D50 is added, the barite with a particle size of 2 μm or less D50 has small particle size, slow settling rate, strong suspension ability and better settling stability. Comparison of comparative example 3 and example 2 shows that the oil-based drilling fluid of comparative example 3 does not bottom out on the glass rod and is not close to the edge when left standing at 200 ℃ for 7 days, which indicates that the system has poor high-temperature emulsion stability and suspension property, and is insufficient to suspend the weighting agent, resulting in the settlement of the weighting agent.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.
Claims (8)
1. The high-temperature-resistant test oil-based completion fluid is characterized by comprising the following components in percentage by weight:
organic soil: 1.0 to 3.0 percent;
calcium oxide: 2.0-4.0%;
high temperature resistant main emulsifier: 1.5 to 3.5 percent;
high temperature resistant co-emulsifier: 1.0-4.0%;
first fluid loss additive: 2.0-4.0%;
second fluid loss additive: 1.0-3.0%;
weighting agent: 80-150%;
the balance of base oil and calcium chloride brine with the concentration of 20-30 wt%, and the volume ratio of the base oil to the calcium chloride brine is 80: 20-90: 10;
the high-temperature resistant main emulsifier is prepared from (1.5-2.5) by weight: (0.8-1.2): 1, an emulsifier A, an emulsifier B and an emulsifier C;
the emulsifier A is C10-18 fatty alcohol-polyoxyethylene ether, and the polymerization degree n is 1-5; the emulsifier B is sodium alkyl succinate sulfonate; the emulsifier C is selected from stearate; the stearate is zinc stearate or sodium stearate;
the high-temperature-resistant auxiliary emulsifier is prepared by mixing polyoxyethylene diene dioleate with an HLB value of 7-8 and polyoxypropylene stearate with an HLB value of 7-9 according to a weight ratio of 1: (1-3) mixing the components in a weight ratio; the first fluid loss additive is selected from at least one of organic lignite, oxidized asphalt and emulsified asphalt; the weighting agent is barite, and the density of the barite is more than or equal to 4.35g/cm3、D50≤2μm；
The second fluid loss additive is prepared by the following steps:
under the magnetic stirring condition of 500-; then adding 4g of dispersant under the protection of nitrogen; after the monomer is completely dissolved, adding 15-30 g of monomer and 0.8g of initiator, fully dissolving, reacting for 5 hours in a constant-temperature water bath at 65 ℃, and adding 2g of cross-linking agent every 30min in the reaction process; after the reaction is finished, cooling to room temperature, washing for 3-4 times by using absolute ethyl alcohol, centrifuging for 10min at the rotating speed of 3000r/min, then carrying out vacuum drying on the obtained product at the temperature of 50 ℃ for 24h, and grinding into powder of 40-60 meshes to obtain the polymer fluid loss additive;
the weight ratio of the monomers is 1: (1-3) acrylamide and butyl acrylate; the initiator is azobisisobutyronitrile or potassium persulfate; the dispersing agent is sodium dodecyl sulfate; the crosslinking agent is divinylbenzene.
2. The high temperature resistant test oil-based completion fluid of claim 1, wherein the organic clay is a lipophilic clay formed by treating bentonite with a quaternary ammonium surfactant.
3. The high temperature resistant test oil based completion fluid of claim 2, wherein the organo-soil is prepared by the steps of:
adding sodium carbonate into bentonite, and heating in water bath at 70-80 deg.C for 3 hr to obtain sodium bentonite; adding quaternary ammonium salt cationic surfactant, heating in water bath at 70-80 deg.C for 2h, drying at 105 deg.C to constant weight, and sieving with 200 mesh sieve to obtain the organic soil; the bentonite, the sodium carbonate and the quaternary ammonium salt cationic surfactant are in a weight ratio of 6: 1: 2.
4. the high temperature resistant test oil based completion fluid of claim 3, wherein the quaternary ammonium salt is selected from at least one of dodecyltrimethylammonium bromide, hexadecyldimethylammonium chloride, and dodecyldimethylbenzylammonium chloride.
5. The high temperature resistant test oil based completion fluid of claim 1, wherein the base oil is selected from diesel, white oil or synthetic base oil.
6. The method for preparing the high temperature resistant test oil based completion fluid according to any one of claims 1 to 5, comprising the steps of, in order:
1) under the condition of high-speed stirring, adding organic soil into base oil according to a certain proportion, stirring for 5-10min to make it fully and uniformly stirred;
2) sequentially adding calcium oxide, a high-temperature resistant main emulsifier, a high-temperature resistant auxiliary emulsifier, a first filtrate reducer, a second filtrate reducer and a weighting agent into the base slurry obtained in the step 1) according to a proportion, and respectively stirring at a high speed for 5-10min to dissolve or uniformly disperse the calcium oxide, the high-temperature resistant main emulsifier, the high-temperature resistant auxiliary emulsifier, the first filtrate reducer, the second filtrate reducer and the weighting agent; wherein, calcium chloride brine is added after the high temperature resistant auxiliary emulsifier is added and before the first filtrate reducer is added, and the mixture is stirred at high speed for 10 to 20 min;
3) adding weighting agent into the glue solution obtained in the step 2) according to a proportion, and stirring at a high speed for 10-20min to ensure that the density of the glue solution reaches 1.60g/cm3～2.10g/cm3；
4) Stirring the semi-finished completion fluid obtained in the step 3) at a high speed for 2-3h, and fully shearing to obtain the high-temperature-resistant oil testing oil-based completion fluid.
7. The preparation method according to claim 6, wherein in the step 2), the calcium oxide, the high-temperature resistant main emulsifier, the high-temperature resistant auxiliary emulsifier, the calcium chloride brine, the first fluid loss additive and the second fluid loss additive which are sequentially added into the base slurry are the next components after being dissolved or uniformly dispersed; in the steps 1) to 4), the high-speed stirring speed is 11000-12000 r/min.
8. Use of the high temperature resistant test oil based completion fluid of any one of claims 1-5 in an oil based test oil completion operation at 200 ℃ or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010193214.0A CN111394073B (en) | 2020-03-18 | 2020-03-18 | High-temperature-resistant oil testing oil-based well completion fluid and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010193214.0A CN111394073B (en) | 2020-03-18 | 2020-03-18 | High-temperature-resistant oil testing oil-based well completion fluid and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111394073A CN111394073A (en) | 2020-07-10 |
| CN111394073B true CN111394073B (en) | 2022-07-08 |
Family
ID=71434297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010193214.0A Active CN111394073B (en) | 2020-03-18 | 2020-03-18 | High-temperature-resistant oil testing oil-based well completion fluid and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111394073B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112063375A (en) * | 2020-09-11 | 2020-12-11 | 中国石油集团西部钻探工程有限公司 | High-temperature-resistant high-density oil-based well completion fluid and preparation method thereof |
| CN116144331A (en) * | 2021-11-22 | 2023-05-23 | 中国石油天然气集团有限公司 | Oil testing completion fluid and preparation method and application thereof |
| CN114015424B (en) * | 2021-12-06 | 2023-03-31 | 沙克(天津)石油技术服务有限公司 | Test oil slurry suitable for high-temperature high-pressure well |
| CN116410391A (en) * | 2021-12-31 | 2023-07-11 | 中国石油天然气集团有限公司 | Nanoemulsion and preparation method thereof, high-temperature-resistant high-density oil-based completion fluid and application thereof |
| CN115232606B (en) * | 2022-08-11 | 2023-06-06 | 中海石油(中国)有限公司 | Suspending agent for high-density oil-based waste liquid and preparation method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101688111A (en) * | 2007-06-18 | 2010-03-31 | 3M创新有限公司 | Reduce the additive of the flow losses of drilling fluid |
| CN102428155A (en) * | 2009-03-23 | 2012-04-25 | 哈利伯顿能源服务公司 | High performance drilling fluids with submicron-size particles as the weighting agent |
| CN103710010A (en) * | 2013-12-30 | 2014-04-09 | 安东石油技术（集团）有限公司 | High-temperature resistant oil base drilling fluid system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015065378A1 (en) * | 2013-10-30 | 2015-05-07 | Halliburton Energy Services, Inc. | Sealant compositions for use in subterranean formation operations |
| US10619432B2 (en) * | 2017-05-17 | 2020-04-14 | Saudi Arabian Oil Company | Oil-swellable, surface-treated elastomeric polymer and methods of using the same for controlling losses of non-aqueous wellbore treatment fluids to the subterranean formation |
| CN110845661B (en) * | 2019-10-28 | 2021-08-20 | 中国石油化工股份有限公司 | Polyacrylamide microsphere system and preparation method and application thereof |
-
2020
- 2020-03-18 CN CN202010193214.0A patent/CN111394073B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101688111A (en) * | 2007-06-18 | 2010-03-31 | 3M创新有限公司 | Reduce the additive of the flow losses of drilling fluid |
| CN102428155A (en) * | 2009-03-23 | 2012-04-25 | 哈利伯顿能源服务公司 | High performance drilling fluids with submicron-size particles as the weighting agent |
| CN103710010A (en) * | 2013-12-30 | 2014-04-09 | 安东石油技术（集团）有限公司 | High-temperature resistant oil base drilling fluid system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111394073A (en) | 2020-07-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111394073B (en) | High-temperature-resistant oil testing oil-based well completion fluid and preparation method and application thereof | |
| US11072738B2 (en) | Environment-friendly high-temperature resistant water-based drilling fluid plugging anti-sloughing agent, preparation method thereof and the water-based drilling fluid | |
| US7741250B2 (en) | Wellbore servicing fluids comprising grafted homopolymers and methods of using same | |
| CN110628398B (en) | Water-based drilling fluid for shale gas well and production method thereof | |
| US3319716A (en) | Fluid loss additive for well fluids, composition and process | |
| WO2004044087A1 (en) | Invert drilling fluids and methods of drilling boreholes | |
| CN111808224B (en) | Copolymer and preparation method thereof, application of copolymer as plugging agent, oil-based drilling fluid and application of oil-based drilling fluid | |
| CN106566496A (en) | Emulsion drilling fluid with high density and low oil-water ratio for shale horizontal well | |
| CA2376585A1 (en) | Oil based drilling fluid | |
| CN108949127B (en) | Low solid phase superhigh temperature water-base drilling fluid and its prepn | |
| CN105189694B (en) | Additives for oil-based drilling fluids | |
| CN106520086B (en) | Water-based drilling fluid for hot dry rock and preparation method thereof | |
| CN107325797B (en) | Low oil-water ratio oil-based drilling fluid and preparation method thereof | |
| CN113930222B (en) | High-temperature-resistant high-density polysulfonate water-based drilling fluid and preparation method thereof | |
| CN109266319B (en) | Full-oil-based drilling fluid and preparation method and application thereof | |
| CN114605969B (en) | Plugging material, plugging type oil-based drilling fluid and preparation method thereof | |
| CN114426815B (en) | Oil-based drilling fluid suitable for strong water-sensitive and easily-collapsed stratum and preparation method and application thereof | |
| CN115725276A (en) | Acid-soluble low-erosion ultramicro-weighted drilling fluid system and preparation method and application thereof | |
| CN110387006B (en) | Acrylamide polymer inverse emulsion and application thereof as supramolecular coating agent in water-based drilling fluid | |
| WO2018144067A1 (en) | Oil-based fluid compositions for hydrocarbon recovery applications | |
| CN114214046A (en) | High-temperature-resistant modified manganese dioxide nano plugging agent and oil-based drilling fluid | |
| CN111154462B (en) | Long-acting stable formate completion fluid and preparation method and application thereof | |
| CN110564387B (en) | Ultrahigh-density environment-friendly gas-to-oil synthetic base drilling fluid and preparation method thereof | |
| AU2017210060A1 (en) | Spacer fluid having sized particulates and methods of using the same | |
| CN108441177B (en) | Drilling fluid surfactant and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |