495 results about "Polymer flooding" patented technology

An improved concentrated surfactant formulation and process for the recovery of residual oil from subterranean petroleum reservoirs, and more particularly an improved alkali surfactant flooding process which results in ultra-low interfacial tensions between the injected material and the residual oil, wherein the concentrated surfactant formulation is supplied at a concentration above, at, or, below its CMC, also providing in situ formation of surface active material formed from the reaction of naturally occurring organic acidic components with the injected alkali material which serves to increase the efficiency of oil recovery.

The invention relates to a microemulsion heavy wax crystal emulsifying dispersant applied to an oil well for tertiary oil recovery, and is mainly used for solving the problem that the oil production rate is influenced due to the high return pressure and the short thermal washing period of the oil recovery well caused by that serious wax precipitations are generated by the oil well which contains thickened oil and is high in polymer flooding and viscosity. The emulsifying dispersant is prepared from the following components by weight percent: 1% to 3% of high-molecular polymer wax inhibitor, 13% to 25% of organic aromatic solvent, 1% to 3.5% of emulsifying agent, 8% to 12% of sulfonate, 10% to 12.5% of alcohol, 10% to 20% of demulsifier and 25% to 35% of water. The emulsifying dispersant has the dual effects of eliminating and preventing the waxy bitumen colloid precipitations with long molecular chains or high carbon number in crude oil from being precipitated, so that the wall sticking quantity of condensate oil is greatly decreased; the running load of the oil well is reduced; and the well washing period is prolonged. Thus, the oil production rate is improved.

The invention relates to a composition capable of greatly improving crude oil recovery efficiency and a preparation method thereof, which mainly solve the problems in the prior art that the oil-displacing agent containing a surface active agent has poor oil displacement efficiency and high application concentration and alkali in alkaline-surfactant-polymer flooding brings corrosion and dirt harm on stratum and oil wells. By adopting the technical scheme of the surface active agent composition comprising fatty alcohol polyoxyethylene ether benzene sulfonate, polymer and water, the problems canbe well solved, and the composition can be used in tertiary recovery of an oil field.

The invention relates to a foam system suitable for profile control and oil displacement of an oil field and an oil displacement method, in particular to a foam system formula used for profile control and oil displacement of the oil field after polymer flooding and a foam profile control oil displacement method. The foam system formula comprises in percentages by weight: 0.1-0.5 wt% of surfactant, 0.05-0.4 wt% of foam stabilizer, 0.08-0.4% of thickening agent, 0.05-1.2 wt% of inorganic salt and the balance of water. In the foam profile control oil displacement method, a ratio of gas to liquid of the foam system is as follows: the volume ratio of gas to liquid is 0.4: 1-1: 1 under an injection pressure. The foam system, provided by the invention, has super strong foam performance and ultra-low interface tension. The foam profile control effect is remarkable after polymer flooding, the yield is improved for more than 20%, and the economic benefit is remarkable.

The present invention discloses process of treating oil-bearing sewage for ternary combination flooding in oil field. The process includes the following steps: 1. gravitational settling of the sewage; 2. combined cyclonic and air floating treatment for oil-water separation; 3. regulating pH value of sewage and adding inorganic flocculant and organic flocculant; 4. further settling; and 5. filtering in a double filter material filter and a modified fiber ball filter. The process can treat sewage to reach the requirement for using as recirculated polymer flooding water with oil content not more than 30 mg/1, suspended matter content not more than 30 mg/1 and granularity midvalue not greater than 5 micron.

The invention discloses a method for activating indigenous microorganisms of an oil reservoir for oil displacement after polymer flooding. The method is characterized in that an oil displacement slug capable of activating indigenous microorganisms of the oil reservoir is injected into a target oil reservoir of the oil displacement through an injection well; the oil displacement slug comprises an activating agent slug and an activating agent protection slug; during an injection process, the activating agent slug and the activating agent protection slug are alternately injected for at least more than 2 times; the total volume of the activating agent slug is two times or more bigger than that of the activating agent protection slug (the most suitable range is controlled to be 2-5 times). According to the method disclosed by the invention, the number of the functional microorganisms of the oil reservoir is increased by injecting an exogenous activating agent; the recovery efficiency can be improved by 3-5 percent after the polymer flooding, and the applicability is good.

The invention discloses a lipopeptide biosurfactant, a preparation method thereof, and an application thereof. The method for preparing the lipopeptide biosurfactant comprises steps that: bacillus subtilis is fermented, such that a fermentation broth is obtained; and the lipopeptide biosurfactant is obtained. When the lipopeptide biosurfactant is formulated with other surfactants, a good synergic effect is provided. As a result of a core oil-displacement experiment employing an alkali-surfactant-polymer flooding complex system of the lipopeptide biosurfactant, water content can be greatly reduced, and recovery efficiency can be improved.

The invention provides a cross-linked polymer microsphere-polymer composite deep water control agent and a using method thereof. The control and drive agent includes water-soluble cross-linked polymer microspheres, water-soluble polymers and water; in the composite deep-seated control and drive agent, the mass percentage of the water-soluble cross-linked polymer microspheres is 0.01% to 0.3%, The mass percent content of the water-soluble polymer is 0.05%-0.5%, and the balance is water. The cross-linked polymer microsphere-polymer composite deep control and flooding agent provided by the present invention has a higher liquid flow redirection ability than conventional polymer flooding, can delay the one-way breakthrough of the polymer solution in the application process, and improve the efficiency of polymer flooding. The sweep coefficient has a higher ability to improve the oil-water phase mobility ratio than the conventional cross-linked polymer solution, and improves the displacement ability of the cross-linked polymer solution, which is more suitable for water injection development reservoirs with heterogeneous porous media.

The invention relates to a flooding system used for improving the recovery factor after polymer flooding and a preparation method thereof, which belongs to the technical field of enhanced recovery of oil fields. A surfactant with unlike charges and a polymer react with each other to produce a high-activity compound; and the high-activity compound is mixed with a non-ionic surfactant to produce the novel flooding system. The novel flooding system solves the problems of the poor temperature resistance and the inorganic high valence cation resistance of the prior flooding system. The novel flooding system has the advantages of high viscocity, ultra-low interfacial tension, low feeding quantity and so on. The system has wide application prospects in oil fields to apply the technology for improving the oil recovery factor.

The invention discloses an oil deposit water-driving exploiting method of an ultra-high water-containing period. The oil deposit water-driving exploiting method solves the problem that the existing water-driving exploiting method of the oil field of the ultra-high water-containing period is poor in effect, adopts a 'two and three combined' exploiting method and particularly comprises: fully utilizing a deployed secondary oil-layer polymer flooding infilled well pattern within about three years before tertiary oil recovery of a secondary oil layer, performing flooding infillled adjusting digging on a first set of polymer flooding layer of the secondary oil layer according to a tertiary oil recovery layer by applying fine geological research results, building a new driving system through selective perforating, organically combining flooding secondary oil recovery with tertiary oil recovery, strengthening flooding secondary oil recovery on a structural unit with remaining oil enriched in the thick oil layer, simultaneously performing proper comprehensive adjusting and then turning into the tertiary oil recovery at a proper time. According to verification, the oil deposit water-driving exploiting method of the ultra-high water-containing period achieves the aim of improving flooding exploitation effect, enhancing oil recovery and prolonging validity of flooding exploitation, and can guide the exploitation and adjustment of the ultra-high water-containing period of the oil field.

The invention relates to the field of industrial water treatment and in particular relates to a method for treating polymer flooding oil-extraction wastewater by employing organic modified sepiolite. The method comprises the following steps: 1) acid activation, namely adding a sepiolite raw material into a hydrochloric acid solution, mixing, stirring, filtering, washing, and drying to obtain sepiolite powder subjected to acid activation; 2) thermal activation, namely roasting and dehydrating the sepiolite powder subjected to acid activation, and cooling and grinding to obtain sepiolite powder subjected to thermal activation; 3) organic modification, namely adding the sepiolite powder subjected to thermal activation into an ethanol aqueous solution of cetyl trimethyl ammonium bromide, mixing, stirring, filtering, washing, drying and grinding to prepare the organic modified sepiolite powder; and 4) adsorption, namely regulating the pH value of the polymer flooding oil-extraction wastewater by using an acid, adding a water-soluble aluminum salt, adding the organic modified sepiolite powder obtained in the step 3) for adsorption, stirring or shaking, standing and settling. The sepiolite serves as a raw material and is low-price and readily available, the process for activation and modification of the sepiolite is simple, and the sepiolite is non-toxic and harmless, has an obvious adsorption effect, rapid in treatment and high in adsorption amount.

The present invention provides a changing-streamline well pattern adjusting method of an oil reservoir in the stage after polymer flooding in the oilfield development process. The changing-streamline well pattern adjusting method after polymer flooding includes the steps that fine geological research is performed, and a fine oil reservoir three-dimensional geological model is established; a numerical simulation model is established, and the saturation distribution rule of remaining oil is analyzed; feasibility analysis for series-of-strata well pattern adjustment is performed; a changing-streamline well pattern adjusting scheme is designed; index prediction of the scheme is performed with an oil reservoir numerical simulation method, and an optimal scheme is selected. The changing-streamline well pattern adjusting method after polymer flooding has very good practicability for gradual decrease of yield of the oil reservoir in the extra-high water containing period after polymer flooding and acceleration of oil production, the oil production rate in the extra-high water containing period after oil reservoir polymer flooding can be effectively and economically improved, and the cumulative oil production of maturing oil fields is substantially increased.

The invention discloses an electrochemical method of oil removal by polymer flooding oil recovery wastewater, which comprises the following steps of: 1, electrolysis; 2, sedimentation. In the process of the electrolysis, tiny oil droplets in the wastewater lose electrons due to discharge on the surface of an anode, charges on the surface of the oil droplets are reduced, and electric potential of interface xi is decreased; and residual polymer pieces in the wastewater after the electrolysis are oxidized and degraded, viscosity of the wastewater is decreased, and water film intensity on the interface of oil/water is reduced. Therefore, the tiny oil droplets after the electrolysis are liable to be converged into large oil droplets and are rapidly separated from the wastewater under the action of cathode hydrogen. As treated by the method, crude oil in wastewater produced in oil extraction by polymer flooding displacement is quite easy for removal with no need for large use of sedimentation tanks, thus saving construction fund for oilfield; the invention has simple process, requires no drug, saves resource and cost and conforms to green chemistry process, quality of the wastewater after the oil removal is obviously crystal-clear; in addition, the device is convenient and safe in operation, easy to control and realize automation, extensively adapted to the amount of water, and convenient for popularization and application.

A device that allows gradually regulation, i.e., non-destructively controlling the flow of injected polymer flooding enhanced oil recovery fluids at each point of injection, using: at least one conduit providing a variable length flow path combined with the centrifugal and other retarding or decelerative forces accessible to a formation engineer by configuring and otherwise arranging the spatial orientation and relative position of each section of such conduit, so as to achieve a never before attained degree of non-damaging flow control density within a compact space.

The invention discloses a reverse-phase demulsifying agent for treating polymer flooding produced liquid of oil fields and a preparation method thereof, and relates to the technical field of oil industries. According to the preparation method, the reverse-phase demulsifying agent for treating the polymer flooding produced liquid of the oil fields is prepared by using ethylene oxide and propylene oxide block polyether taking N,N-dimethylethanolamine as an initiating agent and acrylic acid as raw materials and adding a catalyst and the initiating agent. When the polymer flooding produced liquid is treated by the reverse-phase demulsifying agent compounded with a conventional demulsifying agent for the oil fields, the quality of water obtained by dehydration is good.

The invention relates to a visual experiment device for realizing combined injection and layered injection of a polymer flooding agent and a working method thereof. The experiment device comprises a fluid injection and control system, a polymer seepage simulation system and a produced fluid measurement system, wherein the polymer seepage simulation system comprises a low-seepage flat-plate sand-packed model and a high-seepage flat-plate sand-packed model; a two-way valve is arranged between a connection pipeline I for connecting the high-seepage flat-plate sand-packed model and a connection pipeline II for connecting the low-seepage flat-plate sand-packed model; when the two-way valve is closed, a polymer is injected into the high-seepage flat-plate sand-packed model and the low-seepage flat-plate sand-packed model respectively, and the experiment device carries out a visual experiment for the layered injection of the polymer; and when the two-way valve is opened, the polymer is injected into the high-seepage flat-plate sand-packed model and the low-seepage flat-plate sand-packed model in a combination manner, and the experiment device carries out a visual experiment for the combined injection of the polymer. The experiment device disclosed by the invention realizes completions of the experiments for the combined injection and the layered injection of the polymer flooding agent in case of no interruptions of the experiments.

The invention discloses a microbial oil production method, including a process of displacement of reservoir oil by using bacterial liquid after polymer flooding of oil layers; the bacterial liquid is a mixed liquid or zymotic fluid of bacillus fusiformis 6# CGMCC No.2439, Potsdam Bacillus brevis Po CGMCC No.2441 or Bacillus licheniformis U1-3 CGMCC No.2437 singly mixed with a culture medium, or compatible liquid of the three with the culture medium. The experimental results of model displacement of reservoir oil show that the bacterial liquid is used for displacement of reservoir oil after the polymer flooding, so that recovery ratio is increased by 3-5 percent (OOIP), the bacterial liquid, coupled with polymer protection slug flooding, is used for displacement of reservoir oil after the polymer flooding, so that the recovery ratio is increased by about 7-9 percent (OOIP), and a method with the bacterial liquid displacement and chemical displacement combined is used for displacement of reservoir oil after the polymer flooding, so that the recovery ratio can be increased by 13% (OOIP). The experimental results show that the method of the invention can be widely applied to the field of oil production engineering, especially the field of microbial intensified oil production, and is suitable for large-scale popularization and application.

The invention provides a preparation method of a polymer flooding produced fluid demulsifier, which mainly comprises the following steps: condensing p-tert-butyl phenol, polyethylene polyamine and formaldehyde to obtain a thermoplastic phenol amine resin of which the molecular weights are within a certain range; sequentially and proportionally carrying out ring-opening polymerization on the resin, epoxyethane and propylene oxide; mixing the synthesized products with different molecular weights in a certain mass ratio, and regulating the pH value with acetic acid; and finally, cross-linking with dicarboxylic acid to obtain the final product. The invention aims to solve the problems of severe oil/water emulsification, greater difficulty in oil-water separation, high oil content in dehydrated water and the like in the polymer flooding produced fluid, and the problem that the dehydration effect of the conventional demulsifier on the produced fluid is not ideal.

The invention discloses a visualized experiment method of polymer flooding oil deposit well pattern adjustment aiding chemical flooding. Experiment devices used by the method comprises a needle tube pump, a plate sand filling model, a cross connector, separating metering device for fluid products, a support, a microscopic camera and a computer. The method includes connecting the experiment devices, sequentially allowing the plate sand filling model to be subjected to water saturation and oil saturation, starting a camera function, performing oil displacement by water in an original well mode, performing polymer flooding, keeping the original mode or adjusting to a row-shaped well mode, feeding chemical agent slug for subsequent water flooding, and analyzing screenshots of a recorded video. On the basis of plate sand filling model displacement experiments and by the microscopic camera, the visualized oil displacement experiment of polymer flooding oil deposit well pattern adjustment aiding chemical flooding is performed, real-time dynamic evaluation of displacement effect of well adjustment physical simulation and oil displacement systems, high practicality is achieved, and experiment foundation is laid for researchers on further improvement of oil recovery rate after polymer flooding.

The invention discloses a temporary blocking agent, a composite blockage removal agent and a combined blockage removal method using the temporary blocking agent and the composite blockage removal agent, relating to temporary blocking agents, composite blockage removal agents and combined blockage removal methods. The temporary blocking agent, the composite blockage removal agent and the combined blockage removal method are used for solving the technical problems in a polymer flooding process that the difficulty in polymer injection is caused due to the fact that a polymer is subjected to blockage in a porous medium, and when the blockage removal agent is used directly, the blockage removal agent can preferentially enter unblocked stratums and cannot sufficiently unblock blocked stratums are solved. The temporary blocking agent consists of a surfactant and a freeze promoter. The composite blockage removal agent consists of a host and an initiator. According to the combined blockage removal method, the unblocked stratums are blocked in advance by using the temporary blocking agent so as to enable more subsequently-injected large-dose low-viscosity blockage removal agent to selectively enter the stratums required for being unblocked, the well shut-in is carried out for 2-3 days so as to enable the blockage removal agent and blockages to react fully, and then, the aim of unblocking is achieved.

The invention relates to an organic cross linking polymer flooding system for improving the oil recovery ratio. The organic cross linking polymer flooding system is prepared by the following steps of: adding phenol, part of sodium hydroxide and urotropine into a reaction kettle, warming to the temperature of 50 DEG C and performing the reaction for 30min; adding part of glutaraldehyde and resorcinol, warming to the temperature of 60 DEG C and performing the reaction for 50min; adding the rest of sodium hydroxide, aluminium citrate and aluminum sulfate, warming to the temperature of 70 DEG C and performing the reaction for 20min; and finally, adding the rest of glutaraldehyde, warming to the temperature of 90 DEG C, performing the reaction for 30min and emptying after materials are cooled to obtain the product. The invention establishes the organic cross linking polymer flooding system which has controllable gelling time and strength, good thermal stability and good temperature resistance and salt resistance and is harmless to the environment.

The invention provides an on-line depth profile control method for improving the oil displacement effect of polymer of an offshore production well. Phenolic resin crosslinker is added to form a depth profile control system in the process of polymer flooding of the offshore production well, and by adjusting the mass concentration of the phenolic resin crosslinker, time of jelly glue formation of the depth profile control system and the different depth profile control system retaining positions in an oil deposit are changed so as to block high permeability zones or large pore paths in the polymer flooding oil deposit, thereby expanding the waves and the volume of subsequently injected polymer, increasing the utility ratio of the polymer, improving the effect of development of the polymer flooding and increasing the recovery ratio of crude oil. The depth profile control system has low viscosity and favorable fluidity, can be injected into the deep part of the oil deposit; and after being frozen, enables the sequentially injected polymer to move to low permeability zone so as to play the function of deep profile and has the advantages of favorable thermal stability, long period of validity of deep profile, and the like.

The invention relates to a dual-carboxylate gemini surfactant resistant to high temperature and high salt and a preparation method thereof, which mainly solve the problems that in the prior art, an oil displacement agent containing the surfactant has the defects of low oil displacement efficiency and high using concentration in high-temperature and high-salt conditions and alkali in the trinary alkali-surfactant-polymer flooding brings about corrosion and scale depositing to the stratum and oil wells. In the invention, a technical scheme of N, N-dual-fatty acyl diamine dioxin-propionic acid dioxin-polyoxyethylene ether dual-carboxylate with a general molecular formula shown in the specification is adopted and favorably solves the problem, wherein in the general molecular formula, M is selected from any one of metal ions of potassium, sodium or lithium, R1 is C9 to C17alkyl groups, R2 is C2 to C6 alkyl groups, n is an additive composite number of ethoxy groups (EP) and has the value range of any on integral number from 2 to 7; and the dual-carboxylate gemini surfactant resistant to high temperature and high salt can be applicable to the tertiary oil recovery of oil fields.

The invention discloses a simulation experiment method and device capable of increasing crude oil recovery ratio of multi-layer heterogeneous reservoir. The simulation experiment method comprises the following steps that a multi-layer heterogeneous core is saturated through simulation formation water and crude oil in sequence; the simulation formation water is injected into the multi-layer heterogeneous core for water drive, when the water content in produced liquid is higher than 90%, gel and a polymer/surfactant compound system are sequentially adopted for being injected alternatively for oil displacement, the simulation formation water is adopted for follow-up water drive, and then the purpose of increasing the crude oil recovery ratio of the multi-layer heterogeneous reservoir is achieved; the polymer/surfactant compound system is an aqueous solution of a polymer and a surfactant. According to the simulation experiment method capable of increasing the crude oil recovery ratio of the multi-layer heterogeneous reservoir, related technical parameters are provided for a multi-layer heterogeneous reservoir polymer flooding field test, and service is provided for oilfield production.

The invention discloses a chemical flooding injection method for improving recovery rate of crude oil. The method comprises the following steps of: (1) injecting 0.1 to 0.5 physical volume (PV) of 1,000 to 2,500 mg/L emulsifier plug after polymer flooding; and (2) injecting 0.2 to 0.5 PV of binary composite plug of 500 to 2,500 mg/L polymer with the molecular weight of 20 to 30 million and 0.1 to 0.3 weight percent surfactant. According to the chemical flooding injection method, the residual oil obtained after the polymer flooding is emulsified by injecting the emulsifier plug to form oil-in-water emulsion, and the oil-in-water emulsion is displaced by using binary composite flooding, so that the recovery rate of the crude oil is improved by over 20 percent.

The invention discloses an early warning method for monitoring the development of a cross flow channel among polymer flooding wells. The method comprises the following steps: 1) searching a warning source: based on the dynamic and static files and the monitoring files of a target oil field, searching the influencing factors and the specific representation characteristics to develop a cross flow channel in a reservoir; 2) analyzing the warning: using the gray correlation analysis method to determine the main factors influencing the polymer flooding cross flow to form a polymer flooding cross flow early warning index system; 3) identifying the warning degree: using a fuzzy comprehensive evaluation model to create a polymer flooding cross flow early warning evaluation model; and 4) predicting the warning degree: through the prediction to the dynamic indexes in the polymer flooding cross flow early warning index system determined in step 2 consisting of the static indexes and the dynamic indexes, predicting the development trend of the cross flow channel in the coming periods. The early warning method of the invention is capable of providing theoretical guidance for the implementation of the adjustment and optimization of the polymer flooding development stages so as to improve and increase the polymer flooding efficiency and to increase the producing reserves to the largest possible extent.

The invention relates to a natural carboxylate-polymer microballoon binary composite control system, and a preparation and application thereof. The binary composite control system comprises raw materials of: 0.1-0.5% of polymer microballoon, 0.05-0.5% of natural mixed carboxylate, 0.05% of suspending agent polyacrylamide and the balance of water. The binary composite control system of the invention has effects of profile control and plugging, strong oil scrubbing ability, and can effectively solve a problem of crude oil recovery ratio increase after polymer flooding and avoid damages to stratum and oil extraction equipment caused by alkali.