Study on The Pilot Test with Microbial Profile Modification After Polymer Flooding in Daqing Oil Field

2007 ◽  
Author(s):  
Sui Jun ◽  
Wang Fenglan ◽  
Wang Zhiyao ◽  
Yangqing Bian ◽  
Yang Zhenyu ◽  
...  
Keyword(s):  
Polymer Flooding ◽  
Oil Field ◽  
Pilot Test ◽  
Profile Modification ◽  
Microbial Profile ◽  
Daqing Oil Field

Microbial Diversity Analysis of Reservoirs after Polymer Flooding in Daqing Oil Field at the Earlier Stage of Microbial Profile Modification

2010 ◽  
Vol 113-116 ◽  
pp. 835-839
Author(s):  
Yong Hong Huang ◽  
Guo Ling Ren ◽  
Hong Mei Yuan ◽  
Li Wei ◽  
Xiao Lin Wu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Oil Recovery ◽  
Polymer Flooding ◽  
Oil Field ◽  
Gene Clone ◽  
16S Rdna Gene ◽  
Uncultured Bacterium ◽  
Profile Modification ◽  
Microbial Profile ◽  
Daqing Oil Field

To gain a better understanding of the mechanism and technology of microbial enhanced oil recovery, microbial community structure and diversity of reservoirs after polymer flooding in Daqing oil field at the Earlier Stage of microbial profile modification were studied. 16S rDNA gene clone library was used to assess the structure and diversity of microbial community. The results showed that the dominant microbes of the earlier stage of microbial profile modification are uncultured bacterium, comprising 88.6% of library clones. The cultured strains are composed of Epsilonproteobacteria(5.7%) , Gammaproteobacteria(4.7%) and Firmicutes (1%). Among the Epsilonproteobacteria, Sulfuricurvum accounts for 4.7% of the cultured strains of library clones and Arcobacter accounts for 1%. Besides, the dominant communities also include Pseudomonas and Moorella.

Pilot Test of Alkaline Surfactant Polymer Flooding in Daqing Oil Field

1997 ◽  
Vol 12 (04) ◽  
pp. 229-233 ◽  
Author(s):  
Wang Demin ◽  
Zhang Zhenhua ◽  
Cheng Jiecheng ◽  
Yang Jingchun ◽  
Gao Shutang ◽  
...  
Keyword(s):  
Polymer Flooding ◽  
Oil Field ◽  
Pilot Test ◽  
Daqing Oil Field ◽  
Alkaline Surfactant Polymer

Commercial Pilot Test of Polymer Flooding in Daqing Oil field

2000 ◽  
Author(s):  
Wankui Guo ◽  
Jiecheng Cheng ◽  
Yuming Yao ◽  
Chuanhong Li ◽  
Wenxue Li ◽  
...  
Keyword(s):  
Polymer Flooding ◽  
Oil Field ◽  
Pilot Test ◽  
Daqing Oil Field

An Alkaline Bio-Surfactant Polymer Flooding Pilots in Daqing Oil Field

1999 ◽  
Author(s):  
Wang Demin ◽  
Cheng Jiecheng ◽  
Li Qun ◽  
Li Lizhong ◽  
Zhao Changjiu
Keyword(s):  
Polymer Flooding ◽  
Oil Field ◽  
Daqing Oil Field

The Mechanism of PCP Wells' Tubing and Rod Wear Issue in Polymer Flooding in Daqing Oil Field

2008 ◽  
Author(s):  
He Liu ◽  
Pei Xiaohan ◽  
Peng Baiqi ◽  
Hou Yu ◽  
Wang Yumei ◽  
...  
Keyword(s):  
Polymer Flooding ◽  
Oil Field ◽  
Daqing Oil Field

Review of Practical Experience by Polymer Flooding at Daqing

2009 ◽  
Vol 12 (03) ◽  
pp. 470-476 ◽  
Author(s):  
Dongmei Wang ◽  
Huanzhong Dong ◽  
Changsen Lv ◽  
Xiaofei Fu ◽  
Jun Nie
Keyword(s):  
Oil Production ◽  
Polymer Flooding ◽  
Oil Field ◽  
High Permeability ◽  
Sweep Efficiency ◽  
Molecular Weights ◽  
Well Spacing ◽  
Polymer Flood ◽  
Daqing Oil Field ◽  
Water Cut

Summary This paper describes successful practices applied during polymer flooding at Daqing that will be of considerable value to future chemical floods, both in China and elsewhere. On the basis of laboratory findings, new concepts have been developed that expand conventional ideas concerning favorable conditions for mobility improvement by polymer flooding. Particular advances integrate reservoir-engineering approaches and technology that is basic for successful application of polymer flooding. These include the following:Proper consideration must be given to the permeability contrast among the oil zones and to interwell continuity, involving the optimum combination of oil strata during flooding and well-pattern design, respectively;Higher polymer molecular weights, a broader range of polymer molecular weights, and higher polymer concentrations are desirable in the injected slugs;The entire polymer-flooding process should be characterized in five stages--with its dynamic behavior distinguished by water-cut changes; -Additional techniques should be considered, such as dynamic monitoring using well logging, well testing, and tracers; effective techniques are also needed for surface mixing, injection facilities, oil production, and produced-water treatment; andContinuous innovation must be a priority during polymer flooding. Introduction China's Daqing oil field entered its ultrahigh-water-cut period after 30 years of exploitation. Just before large-scale polymer-flooding application, the average water-cut was more than 90%. The Daqing oil-field is a large river-delta/lacustrine facies, multilayered with complex geologic conditions and heterogeneous sandstone in an inland basin. After 30 years of waterflooding, many channels and high-permeability streaks were identified in this oil field (Wang and Qian 2002). Laboratory research began in the 1960s, investigating the potential of enhanced-oil-recovery (EOR) processes in the Daqing oil field. After a single-injector polymer flood with a small well spacing of 75 m in 1972, polymer flooding was set on pilot test. During the late 1980s, a pilot project in central Daqing was expanded to a multiwell pattern with larger well spacing. Favorable results from these tests--along with extensive research and engineering from the mid-1980s through the 1990s--confirmed that polymer flooding was the preferred method to improve areal- and vertical-sweep efficiency at Daqing and to provide mobility control (Wang et al. 2002, Wang and Liu 2004). Consequently, the world's largest polymer flood was implemented at Daqing, beginning in 1996. By 2007, 22.3% of total production from the Daqing oil field was attributed to polymer flooding. Polymer flooding boosted the ultimate recovery for the field to more than 50% of original oil in place (OOIP)--10 to 12% OOIP more than from waterflooding. At the end of 2007, oil production from polymer flooding at the Daqing oil field was more than 10 million tons (73 million bbl) per year (sustained for 6 years). The focus of this paper is on polymer flooding, in which sweep efficiency is improved by reducing the water/oil mobility ratio in the reservoir. This paper is not concerned with the use of chemical gel treatments, which attempt to block water flow through fractures and high-permeability strata. Applications of chemical gel treatments in China have been covered elsewhere (Liu et al. 2006).

Key Aspects of Project Design for Polymer Flooding at the Daqing Oilfield

2008 ◽  
Vol 11 (06) ◽  
pp. 1117-1124 ◽  
Author(s):  
Dongmei Wang ◽  
Randall S. Seright ◽  
Zhenbo Shao ◽  
Jinmei Wang
Keyword(s):  
Molecular Weight ◽  
Polymer Concentration ◽  
Oil Production ◽  
Polymer Flooding ◽  
Oil Field ◽  
Polymer Injection ◽  
Polymer Flood ◽  
Daqing Oil Field ◽  
Water Cut ◽  
Injection Rates

Summary This paper describes the design procedures that led to favorable incremental oil production and reduced water production during 12 years of successful polymer flooding in the Daqing oil field. Special emphasis is placed on some new design factors that were found to be important on the basis of extensive experience with polymer flooding. These factors include (1) recognizing when profile modification is needed before polymer injection and when zone isolation is of value during polymer injection, (2) establishing the optimum polymer formulations and injection rates, and (3) time-dependent variation of the molecular weight of the polymer used in the injected slugs. For some Daqing wells, oil recovery can be enhanced by 2 to 4% of original oil in place (OOIP) with profile modification before polymer injection. For some Daqing wells with significant permeability differential between layers and no crossflow, injecting polymer solutions separately into different layers improved flow profiles, reservoir sweep efficiency, and injection rates, and it reduced the water cut in production wells. Experience over time revealed that larger polymer-bank sizes are preferred. Bank sizes grew from 240-380 mg/L·PV during the initial pilots to 640 to 700 mg/L·PV in the most recent large-scale industrial sites [pore volume (PV)]. Economics and injectivity behavior can favor changing the polymer molecular weight and polymer concentration during the course of injecting the polymer slug. Polymers with molecular weights from 12 to 35 million Daltons were designed and supplied to meet the requirements for different reservoir geological conditions. The optimum polymer-injection volume varied around 0.7 PV, depending on the water cut in the different flooding units. The average polymer concentration was designed approximately 1000 mg/L, but for an individual injection station, it could be 2000 mg/L or more. At Daqing, the injection rates should be less than 0.14-0.20 PV/year, depending on well spacing. Introduction Many elements have long been recognized as important during the design of a polymer flood (Li and Niu 2002; Jewett and Schurz 1970; Sorbie 1991; Vela et al. 1976; Taber et al. 1997; Maitin 1992; Koning et al. 1988; Wang et al. 1995; Wang and Qian 2002; Wang et al. 2008). This paper spells out some of those elements, using examples from the Daqing oil field. The Daqing oil field is located in northeast China and is a large river-delta/lacustrine-facies, multilayer, heterogeneous sandstone in an inland basin. The reservoir is buried at a depth of approximately 1000 m, with a temperature of 45°C. The main formation under polymer flood (i.e., the Saertu formation) has a net thickness ranging from from 2.3 to 11.6 m with an average of 6.1 m. The average air permeability is 1.1 µm2, and the Dykstra-Parsons permeability coefficient averages 0.7. Oil viscosity at reservoir temperature averages approximately 9 mPa·s, and the total salinity of the formation water varies from 3000 to 7000 mg/L. The field was discovered in 1959, and a waterflood was initiated in 1960. The world's largest polymer flood was implemented at Daqing, beginning in December 1995. By 2007, 22.3% of total production from the Daqing oil field was attributed to polymer flooding. Polymer flooding should boost the ultimate recovery for the field to more than 50% OOIP--10 to 12% OOIP more than from waterflooding. At the end of 2007, oil production from polymer flooding at the Daqing oil field was more than 11.6 million m3 (73 million bbl) per year (sustained for 6 years). The polymers used at Daqing are high-molecular-weight partially hydrolyzed polyacrylamides (HPAMs). During design of a polymer flood, critical reservoir factors that traditionally receive consideration are the reservoir lithology, stratigraphy, important heterogeneities (such as fractures), distribution of remaining oil, well pattern, and well distance. Critical polymer properties include cost-effectiveness (e.g., cost per unit of viscosity), resistance to degradation (mechanical or shear, oxidative, thermal, microbial), tolerance of reservoir salinity and hardness, retention by rock, inaccessible pore volume, permeability dependence of performance, rheology, and compatibility with other chemicals that might be used. Issues long recognized as important for polymer-bank design include bank size (volume), polymer concentration and salinity (affecting bank viscosity and mobility), and whether (and how) to grade polymer concentrations in the chase water. This paper describes the design procedures that led to favorable incremental oil production and reduced water production during 12 years of successful polymer flooding in the Daqing oil field.

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