The exposure and development of grating masks profile made of Shipley have been discussed in this paper. Models of exposure and development have been established to simulate and analyze the final profile of the grating masks, which were compared with experiments results. The models have proved to be correct with the consistency between the simulation and experiments. Main research results are as follows:1. Characteristics and curve data of the Shipleys have been studied and orginated by step experiments . Modeling of the profiles according to the data has been established and compared with experiments results, which have proved to be consistent.2. In order to effectively control the profiles of the grating masks, interaction relationships of the corresponding profiles of grating masks of various categories of Shipleys particularly width ratio variations to the exposure volume, concentration, temperature and development duration of the developer have been simulated, analyzed and compared with experiments. Results of simulation and experiments have proved to be consistent. On the basis of above-stated, interaction rules of the profiles (mainly the width ratios) under different exposure and development conditions have been concluded, through which control methods for profiles have been investigated and achieved, thus guidelines for fabrication of grating masks for qualified profiles have been generated both in theory and in method.3. Under the condition of applying 413.1nm ray for holographic exposure to Shipley, when varying space frequencyof gratings and comparing profile simulation with experiment results, it was detected that sensitive efficiency of shipleys under holographical exposure was only 80% of that under single ray when spacial frequency increased to 10001/mm ~ 20001/mm. On such basis, exposure modeling has been verified and interaction rules between spacial frequency and shipleys (mainly width ratio) has been originated.4. Profile ariation rules and comparison of sensitive of Shipley to two different spectrum under same exposure volumes have been studied and simulated by using 413.1 nm and 441.6 nm laser .
Post about "profile control"
The Research on the Chemical Displacement Improving Development Efficiency in Niuxintuo in Liaohe Oilfield
Based on the geologic feature and the problems faced in water flooding in Niuxintuo Oilfield, we had done the research on displacement efficiency of different flooding systems through indoor physical modeling experiments.We had selected the proper molecular weight and concentration of polymer through experiments, and the results showed that 970×10~4 of molecular weight and the concentration between 500-1500mg/L was matched well with the cores of 100mD, while 500×10~4 of molecular weight was matched well with the cores of 50mD. Selected surfactants formed ultra-low interfacial tension, the range from 0.2% to 0.4%, the compound systems with HLX surfactant and polymer could not form the ultra-low interfacial tension with oil, even without surfactant. While B kind surfactant system and it with polymer compound system could form the ultra-low interfacial tension between 55℃and 70℃.In the paper, we had particularly done the research on influences of polymer flooding and binary compound flooding on the displacement efficiency in artificial cores with various fracture length and coefficient of variation and based on which evaluated the influence of profile control agent on the displacement efficiency.The results showed that the chemical recovery and total recovery of two flooding systems increased as the fracture length increased. The chemical recovery increased as coefficient of variation ranged from 0.6 to 0.85, while total recovery discreased. Adding the profile control agent systems can enhance more recovery than that without it under the same condition. In total, the experiments carried on the heterogeneous cores showed that polymer-surfactant system had better displacement efficiency than polymer did, while the surfactant is the worst.
Laboratory Experimental Study In-house of Multicycle Profile Control and Water Shutoff of Haiwaihe Oilfield
The most part of domestic oil fields are continental deposit multiple zone reservoirs, the permeability alternation of interlayer and inner layer and plane is quite large, so when we operate the water flooding development, the flooding water carries forward along the high permeability area more easily, making the vertical and the planned flooding water to carry forward unevenly, and the flooding water advances suddenly to the oil well prematurely, causing the oil field water flooding prematurely. The multicycle profile control is a multicycle downflow well profile for different purposes for the nonhomogeous reservoir. It can reach the purpose of adjusting the water layer between the situation , controlling of water channeling and improving sweep efficiency of water flooding by adjusting the differences of permeability.In this paper, wo evaluate the performances of 8 kinds Of profile control agents. By changing the temperatures, pHs and salinities of the profile control agents of different formulas and so on, select the profile control agents for the scene production needs; and in Haiwaihe Oilfiel through the core flow experiment we reasearch the water shutoff situations of different permeability cores, we evaluate temperature and stability comprehensively etc, and verify the descending mechanism of profile control with experiments and optimizi the rounds of the profile control and optimize medicine and give the opportunity of profile contrel. The research shows that, if we operate the multi-round profile control water shutoff measures and succeed the rounds of the profile control water shutoff measures timely, we can achieve the desired effect of controllong the water and stabling the oil, displaying the production potential of high moisture content reservoir.
The Research of Big Pore Throat Identify and Water Flooding In-depth Profile Control Technology in Thick Oil Layer
Daqing Oil Field is a multi- layer heterogeneity sandstone oilfield. During the entire process of oil field development, there are many contradictions between two layers, planar layers and inside layers. It has entered the end of high water cut by development, The core data which got by drilling wells show that the effective thickness of the reservoir is greater than 1m still 30.9% of the effective thickness of not washing, the thickness of weak wash is 11.6%, the thickness of common wash is 41.3%, the thickness of strong wash is only 16.2%. Injected water mainly penetrates into the high permeability layer of the thick oil reservoir. The thickness of washed isn’t increase by injected water increasing. Ineffective cycle of injected water is very serious. For improving the effectiveness of water flooding, we carry out the research of big pore throat identify and water flooding in-depth profile control technology in thick oil layer.The paper aimed at forming a big pore throat identify and water flooding in-depth profile control technology in thick oil layer, setting up monitoring technology of a big pore throat, giving identification methods of a big pore throat; setting up evaluation methods and standards of the depth profile control system, giving depth profile control agent type; setting up evaluation methods of water flooding depth profile. It offers technical support and practice experience for slowing down production natural decline rate of thick oil layer water flooding exploitation in LaSaXing oilfields, controlling rise speed of integration water cut and enhancing oil recovery of water flooding.The Paper has gotten some conclusions: defined the concept of a big pore throat, extracted the characteristics of it , defined the concept of FD ,and selected wells which need profile by FD, designed evaluation equipment of profile control agent; defined about flexible factor, compressive strength and filtration coefficient, and set up evaluation method about sellable particle profile control agent and high concentrations of cross-linked polymer profile control agent and a low concentration cross linking polymer profile control agent. These methods have very important significance for controlling the quality of profile control agent. Optimize the various types of profile control agent by physical simulation methods during water flooding and selected the profile control agent for the different conditions; and optimize the design parameters of depth profile by making use of software during water flooding. determined evaluation methods of the depth profile and give an economic evaluation methods of the depth profile during water flooding.
The Investigation of the Flooding Systems with Profile Controlling Function and Their Application in Zhuangxi Oilfield’s Low-to-moderate Permeability Reseavior
This paper, in view of the high temperature and the serious heterogeneity of Zhuangxi 115 block, explores the combination of profile control and oil displacement by studying the high temperature gel for profile control, active sol for deep profile control and flooding, and flooding system of alkli/surfactant.The high temperature gel prepared by PAM, paraformaldehyde and phenol, in terms of the concentration of PAM, can be classified as strong gel and weak gel, the former of which can be used as a long-term agent under 120℃. The stable active sol system synthesized by organic polymers, alkali and surfactants can be used as deep profile control and flooding slug by improving both the sweep efficiency and the displacement efficiency. The flooding system of alkli/surfactant made of petroleum sulfonate, betaine and Na2CO3 can form super-low IFT. The application of this combined techniques of profile control and oil displacement in Zhuang 115-5 well group has increased 1232 tons of oil without regard to the production decline, and the highest decrease of the average water content is 2.02%. Studies above demonstrate the feasibility of this combined techniques to Zhuangxi 115 block.
Study of Water Medium Dispersible Type Polyacrylamide Emulsion Profile Control Technique Used in Offshore Oilfield
Based on the developing and building characteristics of offshore oilfield, such as limited working volume of the platform, easy to be effected by the unfavorable weather, very rigid requirement about safety and environment, short of fresh water. A novel seawater based insant dissolving profile control system was developed, which is friendly to the environment. The water medium dispersible type polyacrylamide emulsion was used as viscosifier, and the water soluble phenol formaldehyde resin was used as crosslinker. Through Investigating the effect of polymer concentration, crosslinker concentration, temperature, salinity and pH value on the performance of the profile control system. The formula and usable range of the profile control system was be optimized: the ideal concentration of the emulsion P-1 is 1000mg·L-1～6000mg·L-1. The satisfactory concentration of the resol SG-3 is 1250mg·L-1～3000mg·L-1, The gelling time can be changed from 48h to 192h. The gel strength is -0.06MPa～-0.095MPa. The temperature range is 50℃～85℃. The highest salinity must be less than 80000mg·L-1 for Na+. The pH range is 3～11. Evaluate the dissolving performance and the viscosifying action of the profile control system. From the lab experiment, we can conclude that at normal temperature the emulsion could dissolved at about 15～20 min. The process of online profile control in offshore oilfield was designed, and the jet mixer and static mixer were designed and manufactured. The online profile control process was simulated in the laboratory. From the test, we can conclude that when the concentration of polymer is less than 0.5%, the polymer and water could mixed sufficiently in 10～15min. It could meet the need of online building. A pilot test was runned in ChengDao oilfield CB1B-6, and the building effect was tracked and evaluated. The water intake rate of main water intake layers Ng41 and Ng42 declined form 82.4% to 65.8%. and the water injecting pressure increased from 5.6MPa to 7.2MPa. The water cut of the correspondent oil well decline about 4.1%. Up to april of 2009, the accumulated increased oil production is about 2000t.
Polymer flooding in Nan Er zone of Sa Nan development area has entered later stage of injecting polymer, partial injection wells of the zone has entered follow-up water flooding stage. Affected by layer heterogeneity, after follow-up water flooding, interlayer and layer contradiction is serious, injecting water sudden along high permeability layer in the plane, inefficient and invalid water cycle is serious. Flooding thickness ratio in vertical layer is greater, wells with ultra-high water cut increase. Therefore, controlling water cut increasing speed, reducing inefficient and invalid water cycle, and excavating residual oil potentiality of thick oil layer are the main direction of EOR after polymer flooding.In this paper, aiming oil layer geological features of Pu I 1-4 of Sa Nan zone, the author developed related physical model and numerical model, studied distribution property and water channeling law of residual polymer after polymer flooding. By evaluating the related property of positive ion amoeba particle profile control agent and, metal cross-linking agent and polymer gel system, the author provided theoretical basis for residual polymer profile control test after polymer flooding in site. The indoor experiment results show that plugging effect of metal cross-linking agent is better; utilization and blocking effect of residual polymer compound with amoeba is improved, which is better polymer re-use formula; polymer gel system has better blocking and resistance to erosion, whose blocking rate to high permeability core is greater, and can form low permeability barrier in high permeability position, has better profile control capability, and there is some increasing oil and reducing water effect in pilot test.
The unique structure and surface activity of nano materials has intrigued many researchers. They have been widely applied in the field of macromolecule emulsion and other popular dispersion systems. Different surface properties are achieved by applying various methods of treatment including surface modification, in order to broaden the scope of its application, based on the traditional inorganic method for producing inorganic nano SiO2. The innate deficiencies of nano SiO2 including high surface energy, easy agglomeration, hydrophilic and oleophobic surface could be tackled by appropriate surface modifications.Several silane coupling agents were used in this paper to modify the surface properties of nano SiO2, which were detected by DTS and FT-IR. According to the result of DTS, the more resin acceptor was used, the larger the diameter of SiO2 had become, but the PDI had declined before it increased, which clearly indicated that modest dose of resin acceptor could increase the lyophobic property and decrease the agglomeration between the particles, thus the dispersion was improved. FT-IR analysis of modified SiO2 proved that the silanol absorption peak decreased as well as the absorption peak of organic resin acceptor chain increased, indicating that the silanol and resin acceptor on the surface of SiO2 had formed chemical bonds, thus the modification had been accomplished.This performance of the modified nano SiO2 was improved, through various analyses of the factors which could affect the properties of this material, including emulsifier, temperature, salt concentration, dose of nano SiO2, altogether lead to a successful formula for selective water plugging in oil fields. Research confirmed the effect of nano SiO2 on the properties of the emulsion that increasing the dose of nano SiO2 could lead to a higher concentration of the emulsion in room temperature. However when the concentration of nano SiO2 was lower than 0.2%, the viscosity of the emulsion was slightly increased instead of decreasing as the temperature raised, indicating modicum dose of nano SiO2 could improve the temperature-viscosity performance of the emulsion, which is later proved by experiment data with a better salt resistance and temperature duration.An enlarged experiment with this modified emulsion is later applied in the oil field, which suggests that the emulsion is ready for industrial scale production. Better performance of water plugging and oil production could be expected.
The application of chemical flooding after water flooding technology has made a great contribution to maintaining oil field high production, stable production and sustainable development at our old oil fields. But there still is about 50% petroleum reserves reversed in the reservoirs after chemical flooding, such as polymer flooding and triaxial compound flooding. And it would ensure the sustainable development that if steam flooding could increase recoverable reserves precipitously, prolong obviously production life on the base of polymer flooding. In this paper, we us the natural cylindrical cores of Daqing oil field to study the routine and profile control steam flooding of non-homogeneous oil reservoir constituted with three parallel cores, the mean permeability is 730×10-3μm2 and variation coefficient is 0.72. This experiment was conducted in the two temperature field conditions of reservoir and injection medium. The results showed that the routine steam flooding after polymer flooding could increase oil recovery factor precipitously in the in non-homogeneous thin oil reservoir. And the scope could come to 26.19%, the oil-steam ratio is 0.127 when the injection temperature is 180℃.But the recovery scope came chiefly from secondary and high permeability zones, homologously were 25.30% and 31.39%, the low permeability layer was only 20.10%, the fractional flow ratio of low permeability layer, secondary and high permeability zones was1:1.75:2.44, there is one severe steam injection disequilibrium between them; at the same time, the recovery ratio raisesed as the increase of steam injection temperature and velocity, and the temperature of increasing scope obviously was 140℃, the scope is 20.61%, which was limited when raising temperature on this base. And the steam flooding recovery of 180℃was only 5.58% higher than that of 140℃; using PAM frozen glue, separated layer injection and profile control, could improve the anisotropic layer and raised utilization extent of low permeability layer, the recovery ratio of profile control steam flooding was 4.79%6.42% higher than that of routine steam flooding when 180℃is over. This made the whole recovery ratio of profile control steam flooding was 2.39%3.21% higher than that of routine steam flooding, come to 28.39%29.47%, and the oil-steam ratio is 0.139; the profile control steam flooding effect of compounding SD-3 active agent and PAM frozen glue is the better, the steam flooding recovery is 30.58% on average, 5.37%6.29% higher than that of routine steam flooding, the oil-steam ratio come to 0.155. Secondly, the ideal effect are successively profile control steam flooding separated layer, steam flooding of slug with foaming agent and profile-control agent, steam flooding of slug with profile-control agent and foaming agent, their recovery ratios are separately 2.39%3.21%、1.53%2.56%、0.53%1.23% higher than that of routine steam flooding, the oil-steam ratios are separately 0.143、0.138、0.129.
As the extension of the water flooding time, the production of the oil well has been declined,the profile control in the high water-cut stage has become an important measures in our country we can obtain the water control stability and the production potential effect after the multi-round profile control has been applied in high water-cut stageAs a strong plugging agent the modified starch has an excellent pour performance and sealing performance. The chemical and physical properties of the modified gel and polymer gel have been studied in this paper. and evaluated the injection-way injection-timing,volume and combinations.study on the static gelling properties and blocked performance of the modified starch and polymer gel The results show that compare to the polymer gel,the modified starch agent has good pour performance and sealing effect;study on the injection-timing of the profile gel,the result shows that the earlier profile control injection the effect is better;study on the volume of the profile gel the result shows that the profile effect will be better when increased the volume in every profile round;study on the influence of the different profile combination in multi-round profile control,we found that composition from strong to the weak distribution of many rounds up of profile control system,can effectively restrain the diminishing phenomenon in multi-round profile control.