Research on Multi-Cup Uniform Flow Gravity Sedimentation Single Well Injection-Production Technique

2013 ◽  
Vol 341-342 ◽  
pp. 534-539
Author(s):  
Guo Xing Zheng

When the oilfield enters the hing water cut stage, the mining faces the problem that the oil-gas gathering system energy consumption reduction needs to decrease produced water and water injection. This paper proposes a novel multi-cup uniform flow gravity sedimentation single well injection-production technique. The downhole oil-water separator separates oil from water. The separated water is directly reinjected into the injection layer. Higher oil content of oil-water mixture is lifted up to the ground. The water injection and oil production in the production wellbore are simultaneous. This paper also designs a crown-like sedimentation cup structure. The experiment shows that the optimum structure of crown oil-water separator is cylindrical with 30 inclination, 12 edges and one partition baord on the tip at the bottom of corrugated shape. Produced liquid contains water 95 percent; efficiency can be increased more than three times by using multi-cup uniform flow gravity sedimentation separator.

2013 ◽  
Vol 803 ◽  
pp. 383-386
Author(s):  
Shu Ren Yang ◽  
Di Xu ◽  
Chao Yu ◽  
Jia Wei Fan ◽  
Cheng Chu Yue Fu

In order to solve the problem of high water cut wells in some oil field in Daqing that it could not get the large-scale application because of the bad separating effect of down hole centrifugal oil-water separator, we optimize the design of multi-cup uniform flux oil-water separator according to the similar separation principle of multi-cup uniform flux gas anchor, and it is obtained to achieve of injection-production technology in the same well which is of high water cut. The design concept of the separator is increasing the number of opening every layer and aperture gradually in subsection from up to down in the design process. The purpose is to get the close intake quantity of every orifice and guarantee the residence time is long enough in the separator, effectively shorten the length of down hole oil-water separator and reduce the production costs and operating costs.


Author(s):  
Terry Potter ◽  
Tathagata Acharya

Abstract Multiphase separators on production platforms are among the first equipment through which well fluids flow. Based on functionality, multiphase separators can either be two-phase that separate oil from water, or three-phase that separate oil, natural gas, and water. Separator performances are often evaluated using mean residence time (MRT) of the hydrocarbon phase. MRT is defined as the amount of time a given phase stays inside the separator. On field, operators usually measure MRT as the ratio of active volume occupied by each phase to the phase volumetric flowrate. However, this method may involve significant errors as the oil-water interface height is obtained using level controllers and the volume occupied by each phase is calculated assuming the interface can be extrapolated from the weir back to the separator inlet. In this study, authors perform computational fluid dynamics (CFD) on a two-phase horizontal separator to evaluate MRT as a function of varying water volume flowrates (water-cut) in a mixture of water and oil. The authors use residence time distributions (RTD) to obtain MRT at each water-cut — a method that results in significantly more accurate results than the regular method used by operators. The numerical model is developed with commercial software package ANSYS Fluent. The code uses the Eulerian multiphase model along with the k-ε turbulence model. The simulation results show agreement with experiments performed by previous researchers. Additional simulations are performed to assess the effect of various separator internals on separator performance. Simulation results suggest that the model developed in this study can be used to predict performances of two-phase liquid-liquid separators with reasonable accuracy and will be useful towards their design to improve performances under various inlet flow conditions.


Author(s):  
Ang Li ◽  
Jianfeng Bai ◽  
Yun Shen ◽  
Hang Jin ◽  
Wei Wang ◽  
...  

The three-phase separator has a wide range of applications in oil production industry. For the purpose of studying the effect of heating temperature, demulsifiers and water content on the separation of oil-water mixture in the three-phase separator, eight kinds of oil samples were taken from different oil transfer stations in Changqing Oilfield and the mixtures were prepared by stirring method. To simulate the two-stage dehydration process, the first stage dehydration experiments without any heating were performed on mixtures at the dose of 100ppm demulsifer at 20°C, and the water cut of these mixtures is the same as that of the gathering pipeline in each oil transfer station. The water cut of the upper crude oil was measured after 40 minutes, and the values of them ranged from 0.5 vol% to 65.2 vol%. No visual stratification was observed for the sample most difficult to separate, so it was selected to conduct the second stage dewatering process. Three bottles of the same mixture were prepared and heated to 30°C, 40°C and 50°C, respectively. The results showed that all of them stratified in 10 minutes, and the water-cut values of the upper oil layer were 1.4 vol%, 0.5 vol% and 0.3 vol%, respectively, compared to 65.2 vol% at 20°C. When the concentration of demulsifier was changed to 200ppm and 300ppm, the results exhibited almost no differences. So it is deduced that the further improvement of heating temperature and demulsifier dose have limited enhancement on oil-water separation. At Last, 35 vol%, 50 vol%, 70 vol% and 85 vol% water cut mixtures of the special oil sample were made to experiment as previously. In consequence, the 35 vol% water-cut emulsions presented a relatively slow rate of oil-water stratification at low heating temperature, and the oil content of the lower separated water was improved by the addition of demulsifier dosage above 100ppm when the water cut was 90 vol%. It is indicated that high heating temperature is necessarry for low water-cut mixtures oil-water separation and can be appropriately reduced to save energy consumption as the water cut continues to rise. The demulsifier dosage is also neccessary be controlled in high water cut period. These experimental data provide the basis for the further optimization operation of the three-phase separator.


2014 ◽  
Vol 18 (01) ◽  
pp. 11-19 ◽  
Author(s):  
J.. Buciak ◽  
G.. Fondevila Sancet ◽  
L.. Del Pozo

Summary This paper deals with the learning curve of a five-plus-year polymer-flooding pilot conducted in a mature waterflood that includes, for example, several works related to injector and producer wells and reservoir management. The scope of this paper is to describe the learning curve during the last 5 years rather than the reservoir response of the polymer-flooding technique; focus is on the aspects related to reduce cost per incremental barrel of oil for a possible extension to other waterflooded areas of the field. Diadema oil field is in the San Jorge Gulf basin in the southern portion of Argentina. The field is operated by CAPSA, an Argentinean oil-producer company; it has 480 producer and 270 injector wells (interwell spacing is 250 m on average). The company has developed waterflooding over more than 18 years (today, this technique represents 82% of oil production in the field) and produces approximately 1600 m3/d of oil and 40 000 m3/d of gross production (96% water cut) with 38 400 m3/d of water injection. The reservoir that is polymer-flooded is characterized by high permeability (average of 500 md), high heterogeneity (10 to 5,000 md), high porosity (30%), very stratified sandstone layers (4 to 12 m of net thickness) with poor lateral continuity (fluvial origin), and 20 °API oil (100 cp at reservoir conditions). Diadema's polymer-flooding pilot started in October 2007 on five water injectors (it includes 13 injectors today) with an injected rate of 1000 m3/d (today, 2000 m3/d). Polymer solution is made with produced water (15,000 ppm brine) and 1,500 ppm of hydrolyzed polyacrylamide polymer reaching 15- to 20-cp fluid-injection viscosity. Oil-production rate from the original “central” producers (wells that are aided with 100% of polymer injection) has increased 100% at the same time as average reduction in water cut is approximately 15%. The main aspects presented in this work are depth profile modification with crosslinked gel injected along with polymer, use of “curlers” to regulate injection in multiple wells with one injection pump without shearing the polymer, and an improved technology on producer wells with progressing-cavity pumps to decrease shut-in time and number of pump failures. The plan for the future is to extend this project to other areas with the acquired knowledge and to improve different aspects, such as water quality and optimization of polymer plant operation. These improvements will allow the company to reduce operating costs per incremental barrel of oil.


2012 ◽  
Vol 591-593 ◽  
pp. 2551-2554
Author(s):  
Jing Xie ◽  
Qiong Liu ◽  
Yan Jiang ◽  
Yu Lin Wang ◽  
Hui Ling Zhu

As a key datum in the petrochemical industry, Water content ratio plays an important role in dehydration, storage selling and petroleum refining. According to the oil well production site, this thesis is based on the oil-water mixture’s density to calculate the water-rate in petroleum, carried on the error analysis to this measuring method, and assessed the scope which this metering equipment is suitable. The wellhead drop back pressure device is effective in monitoring oil wells, to achieve the single well production of display, and when the single well is not working properly, you can discover and resolve problems. The system features are simple structure, easy to carry, stability of Measurement and easy maintenance.


2013 ◽  
Vol 734-737 ◽  
pp. 1354-1357
Author(s):  
Wu Yi Shan ◽  
Wei Lin Cui ◽  
Yong Sheng Li

The separate layer water injection rate determines the result of water injection. In the past, in order to inject a proper amount of water into different intervals, most of the time people would rely on their experiences. By employing this method, the amount of work was enormous and the result was not necessarily accurate. In this paper, five factors that would affect the water injection rate are taken into consideration, such as, thickness of the main well, the connected thickness, permeability, number of connected wells and oil saturation. A method of determining the proper water injection rate of single wells based on analytic hierarchy process is proposed. This method has been proven to be simple and accurate, the test result of a mathematical model also shows it fits the requirements of the oil field exploitation with current water cut and it is of great value to practical applications.


2012 ◽  
Vol 9 (1) ◽  
pp. 124-132 ◽  
Author(s):  
Baghdad Science Journal

Produced water is accompanied with the production of oil and gas especially at the fields producing by water drive or water injection. The quantity of these waters is expected to be more complicated problem with an increasing in water cut which is expected to be 3-8 barrels water/produced barrel oil.Produced water may contain many constituents based on what is present in the subsurface at a particular location. Produced water contains dissolved solids and hydrocarbons (dissolved and suspended) and oxygen depletion. The most common dissolved solid is salt with concentrations range between a few parts per thousand to hundreds parts per thousand. In addition to salt, many produced waters also contain high levels of heavy metals like zinc, barium, chromium, lead, nickel, uranium, vanadium and low levels of naturally occurring radioactive materials (NORM).This study will highlight the main aspects of the different international experiences with the produced water treatment for subsequent reuse or disposal. These different treatment methods vary considerably in effectiveness, cost and their environmental impacts. Samples of produced water from Al-Mishrif formation in ten wells belongs to five fields southern Iraq were taken and analyzed chemically to define the basic features of these waters and to have guide lines for the best strategy that required handling the increased water cut in these fields.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rouhi Farajzadeh ◽  
Siavash Kahrobaei ◽  
Ali Akbari Eftekhari ◽  
Rifaat A. Mjeni ◽  
Diederik Boersma ◽  
...  

AbstractA method based on the concept of exergy-return on exergy-investment is developed to determine the energy efficiency and CO2 intensity of polymer and surfactant enhanced oil recovery techniques. Exergy is the useful work obtained from a system at a given thermodynamics state. The main exergy investment in oil recovery by water injection is related to the circulation of water required to produce oil. At water cuts (water fraction in the total liquid produced) greater than 90%, more than 70% of the total invested energy is spent on injection and lift pumps, resulting in large CO2 intensity for the produced oil. It is shown that injection of polymer with or without surfactant can considerably reduce CO2 intensity of the mature waterflood projects by decreasing the volume of produced water and the exergy investment associated with its circulation. In the field examples considered in this paper, a barrel of oil produced by injection of polymer has 2–5 times less CO2 intensity compared to the baseline waterflood oil. Due to large manufacturing exergy of the synthetic polymers and surfactants, in some cases, the unit exergy investment for production of oil could be larger than that of the waterflooding. It is asserted that polymer injection into reservoirs with large water cut can be a solution for two major challenges of the energy transition period: (1) meet the global energy demand via an increase in oil recovery and (2) reduce the CO2 intensity of oil production (more and cleaner energy).


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