Lithologic Reservoirs

This paper summarized the tendency and advances of petroleum seismogeology in the aspects of seismic sedimentology, seismic reservoir and seismic-petroleum accumulation science. It was pointed out that the research thinking and method of seismic-geology integration take a significant part in present oil and gas exploration. Especially in the exploration of continental thin sand shale interbed, we have obtained remarkable achievements in the research processing of seismic sedimentology（looking for sand bodies）, seismic reservoir（identifying effective sand bodies） and seismic-petroleum accumulation science （finding hydrocarbon reservoir）. It also proposed prospects for the petroleum seismogeology.

Discussion on theoretical innovation of seismic sedimentology

LIU Huaqing， WEI Pingsheng， LI Xiangbo， HONG Zhong， NIU Haiqing， ZHANG Zhaohui

2012, Vol.24(1): 7–12 Abstract ( 481 ) PDF (721 KB) ( 497 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.002

Based on the previous research, combined with exploration practice, it is considered that as a new frontier interdiscipline subject which uses seismic data to study sedimentary rock and its forming process, seismic sedimentology has its unique theoretic basis based on the theories of the modern sedimentology and the geophysics. Its theoretical innovation mainly displays in the following two aspects: ①a depositional body is easier to be resolved with seismic data in horizontal dimension than in vertical; ②primary seismic reflection events do not necessarily follow the geologicaltime surfaces，the seismic frequency content of the data controls the dip and inner reflection configuration of seismic events. These two principles are the basis for using horizontal seismic attributes（seismic geomorphology） to study the sedimentary facies and their evolution，which are the core ideas of the seismic sedimentology.

Advances of paleostructure restoration methods for petroliferous basin

JIU Kai， DING Wenlong， LI Chunyan， ZENG Weite

2012, Vol.24(1): 13–19 Abstract ( 590 ) PDF (579 KB) ( 854 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.003

The paleostructure restoration for petroliferous basin has a close relationship with the hydrocarbon generation and accumulation, and the existed methods of paleostructure restoration have certain limitations and restrict the exploration and development of oil and gas. This paper analyzed the methods of the paleostructure restoration including pagoda chart，isopach map，balanced section，paleostructure restoration through seismic attributes, paleostructure restoration in three dimensional space and the reconstruction of the same deformable body, and pointed out the application conditions and problems of each method in practice. The recovery of eroded amount，de-fault and de-fold, decompaction and correction of ancient water depth are inevitable key technologies. Whether we can use the technologies reasonably influences the accuracy of the paleostructure restoration. It also put forward the development trends of paleostructure restoration method, which provides instructions for the paleostructure restoration.

Origin of dolomite of Lower Ordovician Yingshan Formation in Tazhong area

WANG Zhenyu，YANG Liuming，MA Feng，YANG Liuyan，ZANG Shiqing，LUO Xinsheng

2012, Vol.24(1): 20–25 Abstract ( 487 ) PDF (547 KB) ( 449 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.004

Yingshan Formation of Lower Ordovician in Tazhong area of Tarim Basin becomes an important object for marine carbonate rocks exploration, and it developed large amounts of qualified dolomite reservoirs. Due to the deep burial and low degree of exploration of dolomite, the cognition of its origin is not perfect. The well drilling data from 8 wells were applied to analyze the petrology and geochemistry characteristics of the dolomite of Yanshan Formation. The result shows that there developed 5 types of dolomites; the C and O isotope is generally negative and Sr isotope is positive. Combined with trace elements, cathodoluminescence and other geochemistry characteristics, it was considered that there are three origin mechanisms, including deep burial origin, hydrothermal origin and near surface evaporation seawater origin.

Pore characteristics and origin of reservoirs in the southern Tamtsag Sag

YAN Bo， LV Xiaohui

2012, Vol.24(1): 26–29 Abstract ( 423 ) PDF (581 KB) ( 590 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.005

The southern Tamtsag Sag is located in the southernmost central rift of Hailaer-Tamtsag Sag. The main oilbearing layers are Tongbomiao and Nantun Formation（he first and second member of Nantun Formation）. The core data combined with thin section, casting thin section and scanning electronic microscope were applied to study the rock types and pore characteristics of Nantun and Tongbomiao Formation. The result shows that the reservoir of Tongbomiao Formation is mainly of tuffaceous sandstone, the reservoir of the first member of Nantun Formation is mainly of ordinary sandstone, the reservoir of the second member of Nantun Formation is mainly of sandstone, and these reservoirs all developed secondary pores. It is also considered that the reservoirs in the study area are mainly controlled by rock types, albitization and clastic particles shell.

High resolution sequence stratigraphy in fan delta facies: A case study from Upper Karamay Formation reservoir in Bai-21 well area in Karamay Oilfield

CHEN Lihua，LU Yanqiu，XU Huaimin，XU Zhaohui

2012, Vol.24(1): 30–35 Abstract ( 496 ) PDF (618 KB) ( 416 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.006

n order to recognize the characteristics of fan delta facies reservoir and improve the reservoir description accuracy, this paper carried out the study on the reservoir of Upper Karamay Formation based on high resolution sequence stratigraphy and the strata cyclicity as well as sedimentology response caused by different grade base level change. The Upper Karamay Formation in Bai-21 well area can be divided into one long-term sequence cycle, two middle-term sequence cycles, 14 short-term sequence cycles and 33～37 super-short-term sequence cycles. The shortterm sequence cycles can be divided into two basic structure types which are up-deepening asymmetry and upshallowing asymmetry. The sedimentary sequence, structure type, stacking pattern and distribution pattern of supershort- term sequence cycles in the process of base level change were discussed in detail. The sequence stratigraphic framework was built up by making short-term sequence as isochronous stratigraphic correlation unit. The sedimentary characteristics of sand body and the oil-gas distribution were analyzed. All these studies provide a good foundation for reservoir research and later development of Upper Karamay Formation in the Bai-21well area.

Structural characteristics of Miaoxi Sag

ZONG Yi， LIANG Jianshe， LIU Lifang

2012, Vol.24(1): 36–39 Abstract ( 439 ) PDF (551 KB) ( 560 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.007

Miaoxi Sag is located in the southeast of Bohai Bay, and it is made up by the North subsag, the East subsag and the South subsag. The seismic interpretation and fracture analysis show that the North subsag and East subsag is respectively constituted by two dustpan-shaped fault depression, it is graben structure in the north of South subsag, and dustpan-shaped fault depression in the south. The influences of Tan-Lu fault zone on each subsag are different. The North subsag and East subsag are influenced by extended tectonic system, and the South subsag is influenced by Tan-Lu fault. The extended faults in the three subsags are caused by the strike-slip faults, constituting a part of strike-slip tectonic system, and the shallow faults are transformed by Zhangjiakou-Penglai fault zone.

Characteristics and evaluation of Chang 81 reservoir of Zhuang 36well area in Xifeng Oilfield

PAN Jingwen，WEN Zhigang，DIAO Fan，ZANG Chengguang

2012, Vol.24(1): 40–45 Abstract ( 450 ) PDF (669 KB) ( 522 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.008

In view of the problems of the oil yield decline and the rapid water saturation in single well of Zhuang 36 well area in Xifeng Oilfield, Ordos Basin, the logging data, rock section, scanning electronic microscope, X diffraction, grain size analysis and mercury penetration were used to analyze the lithology characteristics, physical properties, pore throat of Chang 81 reservoir. The result shows that Chang 81 reservoir belongs to low-ultra low porosity and low-ultra low permeability reservoir; the main sandstone is fine-grained lithic arkose; the reservoir mainly developed intergranular pore and dissolved pores; the pore throat structure is the type of small pore and micro throat. Sedimentation and diagenesis have impacted on the reservoir properties together, which leads that the physical properties of subsea distributary channel and mouth bar were better than that of channel frank. According to the physical properties and pore structure parameters, the reservoir in the study area can be divided into four types. The typeⅠbelongs to the best reservoirs, The type Ⅱ belongs to the good, the type Ⅲ belongs to the bad and the type Ⅳ belongs to the worst. The water producing wells mainly distributed in the reservoirs of the type Ⅳand type Ⅲ, and the oil yield in the wells of the type Ⅰ is good and stable.

Reservoir characteristics of Xujiahe Formation in northeastern Sichuan Basin

LI Kuo，ZENG Tao，PAN Lei

2012, Vol.24(1): 46–51 Abstract ( 523 ) PDF (600 KB) ( 718 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.009

According to the test of drilling cores and outcrop samples, thin section analysis and scanning electronic microscope, this paper studied the reservoir petrologic characteristics, reservoir space types, diagenesis, pore structure and pore types of Xujiahe Formation in northeastern Sichuan Basin. The result shows that the reservoir sandstone of Xujiahe Formation presents petrological characteristics of medium-fine grained texture, lower compositional maturity and medium textural maturity. The reservoir pore spaces include residual primary intergranular pores, secondary dissolved pores and fractures. The pore structure is mainly of fine pore and thin throat. The study area is mainly of typical reservoir with low porosity and low permeability.

Characteristics of pore structure of Chang 2 oil reservoir set of Yanchang Formation in Dong-Han area

LI Yanjing， GAO Chao， DENG Jie， KONG Lingfei

2012, Vol.24(1): 52–56 Abstract ( 467 ) PDF (658 KB) ( 590 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.010

The property analysis, thin sections, scanning electronic microscope and mercury injection tests were applied to study the characteristics of low permeability reservoir and pore structure and discuss the effect of pore structure on physical properties of low permeability reservoir. The result shows that the pore types include residual intergranular pores, dissolved pores，intercrystalline pore and micro-fracture，dominated by dissolved pores. Fine throat is the main throat type. Pore throat structure is mainly of middle pore-thin throat，followed by eyelet-thin throat and macropore-medium throat. The greater the pore throat radius is, the better the permeability of low permeability reservoirs is. Sorting coefficient and skewness show the characteristics of low permeability reservoirs such as various types of throat, different sizes and strong microscopic heterogeneity.

Characteristics of Oxfordian carbonate reservoir in Agayry area,Amu Darya Basin

LIU Shilei， ZHENG Rongcai，YAN Wenquan, LIAO Jun， JIANG Hao，WANG Xiaoping

2012, Vol.24(1): 57–63 Abstract ( 579 ) PDF (731 KB) ( 574 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.011

High-yielding industrial gas had been gained in Oxfordian carbonate rocks in Agayry area, Amu Darya Basin, thus a detailed study on the characteristics of the reservoir will be important to guide its hydrocarbon exploration and development. Based on the detailed description of drilling cores and comprehensive analyses of casting thin sections, scanning electronic microscope and reservoir properties, it was believed that the reservoir and its distribution are mainly controlled by sedimentary microfacies and diagenesis. The sandy beach and bioclastic beach are the foundation of the reservoir development, dissolution is the key factor for the reservoir formation, and the fracturing greatly enhanced the reservoir quality. All these features improved the accuracy of the reservoir prediction and evaluation, and provides principles for the efficient development of gas resources.

Migration and accumulation model of slope area in big depression with outside source rock: An example from Fuyu oil layer in Chang 10 area, Songliao Basin

LIU Zongbao，JIA Junjie，ZHAO Miao，SUN Qinghua

2012, Vol.24(1): 64–68 Abstract ( 488 ) PDF (550 KB) ( 431 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.012

Chang 10 area is of the typical accumulation outside effective hydrocarbon source on slope of depression. The cores，well loggings and seismic data were used to analyze the main controlling factors such as oil origin，sand body distribution, structural features and oil and water distribution. The result shows that oil was generated from syncline source rocks of the first member of Qingshankou Formation in Sanzhao Sag; T2 fault concentrates into belts in plane, and oil sources faults that was active accumulation are border faults around concentrated belts; Fuyu oil layer developed river-dominated delta under Baokang source from southwest, and microfacies were mainly distributary channels with a sedimentary evolution of reliction to transgression overlaying in vertical; oil was distributed on the top of Fuyu oil layer in vertical, and decreased from structurally low position to high position, distributing in step shape, under the effect of insufficient supply on the slope. Accumulation mode is that oil which was generated from source rock in the first member of Qingshankou Formation first downward migrated to Fuyu oil layer through oil-source faults under the action of overpressure, then laterally migrated through preferential migration pathways formed by matching between channel sand developed during the largest retrogradation（bottom of FuⅠ） and oil faults under the action of buoyancy，and oil accumulated in fault-concentrated belts in plane while distributed in upper preferential transforming layers in the vertical.

Seismic processing and identification technology for Paleogene turbidite in Liaodong Bay

YAO Jian， ZHENG Jinggui， DU Xiaofeng， SUN Hefeng

2012, Vol.24(1): 69–73 Abstract ( 392 ) PDF (669 KB) ( 484 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.013

The turbidite reservoir is characterized by wide distribution, deep burial and strong concealment, so it is difficult to identify the turbidite reservoir by conventional exploration technology. The wavelet frequency-dependent imaging, structure-oriented edge-preserving smoothing and well control for resolution improvement combined with geophysical processing techniques such as color inversion, dip, azimuth and coherent analysis were used to describe the geometrical features of turbidite. In addition, the new geophysical identification technologies for Paleogene turbidite were applied properly for Liaodong Bay area. The field study confirms that the new techniologies lay a good foundation for stratigraphic-lithologic reservoir in this area.

Realization and optimization of discrete fracture network model of buried hill fractured reservoir in C oilfield, Bohai Bay

WANG Hui， HU Guangyi

2012, Vol.24(1): 74–79 Abstract ( 480 ) PDF (621 KB) ( 548 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.014

Based on the geological features of fractured reservoir in C oilfield of Bohai Bay, the data of cores, well logging and outcrop were applied to analyze the origin and characteristics of buried hill fractured reservoir. It is considered that stress field and fault are the two main controlling factors for fracture development. Combined the stress field with fault, a set of discrete fracture network （DFN） models was generated to predict the fracture distribution. Through geological features comparison and dynamic data test, the best DFN model was chosen for C oilfield. Based on the optimized DFN and fracture aperture, the porosity model, permeability model and fracture porosity model were established which provides geological foundation for making more reasonable oilfield development plan.

Uncertainty analysis of fluvial reservoir in oilfield early development period based on stochastic modeling: A case study from A oilfield in Bohai Bay

XUE Yanxia， LIAO Xinwu， ZHAO Chunming， HUO Chunliang， ZHANG Rucai

2012, Vol.24(1): 80–83 Abstract ( 467 ) PDF (376 KB) ( 570 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.015

Taking A oilfield in Bohai Bay as an example, this paper introduced a method of evaluating reservoir risk that combines Monte-Carlo method with stochastic modeling, aiming at the problem of uncertainty analysis of geological model in china and the characteristics of fluvial reservoir in Bohai Bay. The reason that the uncertainty parameters exist in geological model was analyzed. Based on stochastic reservoir modeling, combined with experimental design, multinomial response surface of the main uncertainty factors and reserves and Monte-Carlo method, the effects of uncertainty factors on the reserves were estimated quantitatively and the risk and potential of the reservoir were predicted, which provides a set of optimum geological models for numerical reservoir simulation.

Numerical simulation of high accuracy seismic pure wave source

CHEN Keyang

2012, Vol.24(1): 84–91 Abstract ( 526 ) PDF (758 KB) ( 704 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.016

In order to improve the numerical simulation precision of the compression wave source and shear wave source by computer, this paper put forward the grid setting method of high-order high accuracy pure compression wave and shear wave source, compared with many source grid setting proposals, and further validated it by the theory. The wave field separation numerical experiments on the isotropic elastic medium complex models were carried out, and the result shows that the setting method of traditional pure wave source has problems of low order and residual wave field. While the proposed method is with little disturbing wave field and perfect numerical simulation accuracy, which can not only achieve the goal of reappearing the seismic prospecting with the compression wave source and shear wave source, but also observe the special wave fields which are unclear with traditional numerical method. Therefore the proposed method is in favor of verifying and perfecting the seismic wave dynamic theory, and can guide the seismic acquisition, seismic processing and seismic interpretation.

Application of seismic curvature based on horizon to carbonate fault prediction: An example of an area in Tabei, Tarim Basin

CUI Lijie， HE Youbin， WANG Jinxi， WANG Zhenqing， HU Zaiyuan

2012, Vol.24(1): 92–96 Abstract ( 457 ) PDF (723 KB) ( 625 )

The Ordovician carbonate rocks in an area of Tarim Basin are characterized by old geological age, large burial depth and poor developed primary matrix pores, and the favorable reservoir distribution is controlled by faults. So it is very important to carry out the fine prediction of fault in this area. The seismic curvature technique based on horizon was used to predict the fault at the top boundary of Ordovician Yijianfang Formation. The minimum negative curvature and maximum positive curvature were selected from the commonly used seismic curvatures to describe the fault, and the result shows the good effects. Through the interactive analysis of seismic profile and plane map of seismic curvature based on horizon, it is found that there are good corresponding relations among the level, nature and strike of the predicted faults.

Calculation method of porosity based on formation component analysis

ZHANG Zhaohui，GAO Chuqiao，LIU Juanjuan

2012, Vol.24(1): 97–99 Abstract ( 459 ) PDF (343 KB) ( 523 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.018

Porosity calcula tion is the key for the evaluation of volcanic rocks, carbonate rocks, tight sands and other heterogeneous reservoirs. The method based on formation component analysis was proposed to calculate porosity. With the full use of conventional logging data and ECS （Elemental Capture Spectroscopy） logging data, the log data sensitive to formation component were selected, the theoretical log response of formation component was determined by making crossplot. The equation was established based on the formation component analysis. The volume content of the formation components was calculated by least squares method, and then the porosity was determined. This calculation method was applied to the evaluation of igneous reservoir in A study area of Santanghu Basin, and good result has been achieved. And it provides some reference for other unconventional reservoir about porosity calculation.

Application of two-dimensional trend surface to geological modeling of Chang 8 oil reservoir set in Fuxian area

HE Xing1，YANG Youyun，LI Yingyan

2012, Vol.24(1): 100–103 Abstract ( 475 ) PDF (482 KB) ( 567 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.019

Due to the complexity of variation function analysis for modeling adjustment, only using stochastic modeling is difficult to obtain ideal effect in areas with complex geological conditions. In this case, we can introduce twodimensional trend surface analysis method to constrain the stochastic modeling. Taking Chang 8 oil reservoir set in Fuxian area as an example, this paper utilized the method of vectoring sedimentary facies map and assigning the generated two-dimensional trend surface to carry out sedimentary facies modeling, and adopt the two-dimensional trend surface generated by isochore interpolation method to constrain the stochastic simulation of porosity. The result shows that the sedimentary facies model and porosity model established by this method respectively match the sedimentary facies and porosity distribution well in the study area. At the same time, the two-dimensional trend surface analysis method can also be combined with other modeling constraint method to constrain the geological model.

Calculation method for natural gas reserve-production ratio in different development stages

ZHAO Xiaolong， LIU Xiangjun， LIU Daojie

2012, Vol.24(1): 104–107 Abstract ( 519 ) PDF (269 KB) ( 405 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.020

Natural gas reserve-production ratio is a key index that describes the relationship between production scale and explored reserves. Accurate calculation of natural gas reserve-production ratio has important guiding significance for ensuring natural gas reasonable development and making national long-term strategy objectives. The production characteristics in the gas production rising stage, stable stage and decline stage were analyzed. Based on the relationship equations of production rising rate, recoverable reserve displacement rate and production decline rate, the calculation methods of natural gas reserve-production ratio in three different development stages were derived. At the same time, considered the relationship between recoverable reserve recovery percentage and reserve-production ratio in natural gas development, the relationship equations between recovery percentage and reserve-production ratio, reserves displacement rate, production rising rate（or production decline rate） were derived. The study result indicates that natural gas reserveproduction ratio shows obvious downtrend in the gas production rising stage, holds relatively stable in stable stage, and begins to descend smoothly in decline stage. The case analysis shows that this new method is reliable and practical for calculating natural gas reserve-production ratio in different development stages.

Prediction of minimum miscibility pressure in CO2 flooding based on general regression neural network

LI Hu， PU Chunsheng， WU Feipeng

2012, Vol.24(1): 108–111 Abstract ( 438 ) PDF (296 KB) ( 688 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.021

To reduce the inconvenience and errors in traditional prediction methods for minimum miscibility pressure （MMP）, a general regression neural network（GRNN） model was established for MMP prediction in CO2 flooding. The main factors affecting CO2 MMP, such as reservoir temperature, mole percentage of oil components (volatile and intermediate） and molecular weight of C5+ , were employed as the input variables of the GRNN, and the CO2 MMP was used as the output variable. To evaluate the advantage of the new method, the predicted results were compared between the GRNN model and the traditional empirical formula. The results show that the GRNN model is feasible for CO2 MMP prediction, and also has the characteristics of good precision, fast convergence, wide applicability and simple application.

Study on law of injectivity index per meter change with cumulative water injection

LI Biao，TANG Hai，LV Dongliang，LIU Pengchao，WANG Lianguo

2012, Vol.24(1): 112–116 Abstract ( 429 ) PDF (360 KB) ( 564 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.022

When a production well adjusted to an injection well, the water injectivity index of the well will keep increasing with the oil near the well bottom being droved away by the injected water. However, there is no accurate formula to describe the law so far. Based on the Buckley-Leverett equation and the classical Darcy equation, combined with the relationship curve of water cut and water saturation, the relationship formula of the injectivity index per meter and cumulative water injection per meter was deduced. Finally, the field data was used to analyze and verify the validity of the formula. This formula provides a theoretical basis for the future calculation of injectivity index per meter and the well injection allocation.

Study on calculation of dynamic reserves and water influx in fractured condensate gas reservoir

CHEN Heng， DU Jianfen， GUO Ping， LIU Donghua， XIAO Feng， YANG Zuoming

2012, Vol.24(1): 117–120 Abstract ( 477 ) PDF (297 KB) ( 700 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.023

Based on the principle of material balance, combined with the compressibility and irreducible water saturation differences between the matrix and fracture system, a new material balance equation for fractured gas condensate reservoir with low condensate oil content and active edge and bottom water was established. Moreover, a simple method of calculating dynamic reserves and water influx of fractured condensate gas reservoir was put forward by introducing elastic storativity ratio. A case study shows that the OGIP and water influx were too lager if calculated by using apparent formation pressure method and depending on the geological reserves method considering only the single porosity media. Therefore, the new material balance equation could calculate the OGIP and water influx more accurately due to considering double porosity media.

A new deliverability model for horizontal gas well under non-uniform damage

CHEN Feng，LI Xiaoping，WANG Zitian，TIAN Min

2012, Vol.24(1): 121–124 Abstract ( 417 ) PDF (440 KB) ( 451 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.024

Forecasting the deliverability of horizontal well accurately plays an important part in economical and effective exploitation of oil and gas field. When we use horizontal well to exploit oil and gas field, the flow processing includes reservoir flow and wellbore flow. Taking both non-uniform damage around wellbore and pressure drop along the wellbore into account, we establish a semi-analytic model to estimate the deliverability of horizontal gas well. Then use this new model to calculate the production of a horizontal gas well, compare with the production under uniform damage, and respectively analyze the effect of pressure drop along the wellbore under different permeability and non-uniform damage around wellbore on well deliverability. This new model can provide theoretical basis for the deliverability analysis for horizontal gas well and multilateral gas well.

Sensitivity analysis of polymer flooding characteristic parameters on water cut curve

ZHANG Wei，YU Gaoming，HU Haixia，SHI Lihua，ZHANG Xin

2012, Vol.24(1): 125–128 Abstract ( 395 ) PDF (310 KB) ( 639 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2012.01.025

Water cut curve matching is the important part of the history matching of polymer flooding. There are two important fitting points in the water cut curve, which are polymer flooding effective point and water cut lowest point. In the numerous affecting polymer flooding factors, we selected relative viscosity of polymer solution, polymer adsorptive capacity, residual resistance factor and inaccessible pore volume as characteristic parameters for sensitivity analysis, and defined the sensitivity coefficient. Through sensitivity analysis, we know that the values of fitting points reduce with the increase of relative viscosity of polymer solution, residual resistance factor and inaccessible pore volume, but increase with the increase of polymer adsorptive capacity. The sensitivity of polymer flooding characteristic parameters on water cut curve from strong to weak is: polymer adsorptive capacity, relative viscosity of polymer solution, inaccessible pore volume and residual resistance factor.