Seismic stratigraphy and oil recovery potential of tide‐dominated depositional sequences in the Lower Misoa Formation (Lower Eocene), LL-652 Area, Lagunillas Field, Lake Maracaibo, Venezuela

Geophysics ◽  
1997 ◽  
Vol 62 (5) ◽  
pp. 1483-1495 ◽  
Author(s):  
William A. Ambrose ◽  
Eulise R. Ferrer
Keyword(s):  
Oil Recovery ◽  
Resource Base ◽  
Lower Eocene ◽  
Maracaibo Basin ◽  
Recovery Potential ◽  
Well Spacing ◽  
Well Pattern ◽  
Remaining Oil ◽  
North Part ◽  
Original Oil In Place

Structurally complex, heterogeneous, estuarine‐delta and tide‐dominated shelf reservoirs in the Lower Misoa Formation (Lower Eocene C Members) in the LL-652 Area of Lagunillas Field in the Maracaibo Basin, Venezuela, had produced 135 million stock‐tank barrels (MMSTB) of oil as of 1993 but have a low recovery efficiency of 22 percent. In an 18-month joint study, the Bureau of Economic Geology (BEG) and Lagoven, S. A., demonstrated that these reservoirs will contain more than 900 MMSTB of unrecovered mobile oil at the end of primary recovery operations at the current 80‐acre well spacing. Two‐dimensional seismic, core, geophysical log, and production data were integrated to improve estimates of hydrocarbon reserves and to identify potential areas for secondary‐recovery projects in Lower Eocene reservoirs in the LL-652 Area. Maps of hydrocarbon pore volume (SoPhih) and remaining oil were derived from improved petrophysical characterization and production apportioning to specific reservoir horizons by permeability feet (kh). These maps indicate that most remaining oil lies in the poorly developed and structurally complicated north part of the field and where narrow [less than 2000 ft (<610 m) wide], high‐SoPhih belts are intersected by sealing and partly sealing reverse faults. The original‐oil‐in‐place resource base of the C Members in the LL-652 area increased by 867 MMSTB (60%) to 2318.2 MMSTB, mainly in the C-3-X and C-4-X Members, by identifying additional reservoir areas and improving quantification of porosity and other petrophysical parameters. Extended development on the current 80-acre [1968-ft (600-m)] well pattern will increase reserves from 127 to 302 MMSTB. However, 116 MMSTB, in addition to the 302 MMSTB, can be produced from 102 geologically based infill wells strategically targeted to tap areas of high remaining oil saturation in narrow sandstone bodies poorly contacted at the current well spacing. Horizontal and inclined wells in steeply dipping strata can capture additional volumes of poorly contacted mobile oil.

The Research of Flood Pattern Completeness in the Thin and Poor Oil Layers of South West II Area

2012 ◽  
Vol 594-597 ◽  
pp. 2541-2544
Author(s):  
Xiao Hui Wu ◽  
Kao Ping Song ◽  
Chi Dong ◽  
Ji Cheng Zhang ◽  
Jing Fu Deng
Keyword(s):  
Oil Recovery ◽  
Water Flooding ◽  
South West ◽  
Oil Distribution ◽  
Well Pattern ◽  
Remaining Oil ◽  
Tertiary Oil Recovery ◽  
Well Pattern Optimization ◽  
Numerical Simulation Technique

As line well pattern is the main development technique in the thin and poor oil layers of Daqing Oilfield South West Ⅱ PⅠ group, the layers have been idle and the degree of reserve recovery is far less than the region level. In response to these problems, we analyzed the balanced flood performance of various layers and the remaining oil distribution through numerical simulation technique. It shows that, the main remaining oil type of intended layers is caused by voidage-injection imperfection. Considering the needs of the follow-up infill well pattern and tertiary oil recovery, we decided to keep the well network independent and integrated without disturbing the pattern configuration and main mining object of various sets of well pattern. Finally we confirmed to perforate-adding the first infill wells of intended layers to consummate the water flooding regime. Through analyzing the production target of different well pattern optimization programs relatively, it shows that the best program has regular well pattern and large drilled thickness.

scholarly journals Asynchronous Injection-Production Process: A Method to Improve Water Flooding Recovery in Complex Fault Block Reservoirs

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Shibao Yuan ◽  
Rui Wang ◽  
Haiyan Jiang ◽  
Qing Xie ◽  
Shengnan Chen ◽  
...  
Keyword(s):  
Production Process ◽  
Oil Recovery ◽  
Water Injection ◽  
Central Area ◽  
Water Flooding ◽  
Production Stage ◽  
Fault Block ◽  
Complex Fault ◽  
Well Pattern ◽  
Remaining Oil

The complex fault block reservoir has the characteristics of small area and many layers in vertical. Due to the influence of formation heterogeneity and well pattern, the situation that “water fingering is serious with water injection, on the contrary, driving energy is low” frequently occurs in water flooding, which makes it difficult to enhance oil recovery. Asynchronous injection-production (AIP) process divides the conventional continuous injection-production process into two independent processes: injection stage and production stage. In order to study oil recovery in the fault block reservoir by AIP technology, a triangle closed block reservoir is divided into 7 subareas. The result of numerical simulation indicates that all subareas have the characteristic of fluid diverting and remaining oil in the central area is also affected by injected water at injection stage of AIP technology. Remaining oil in the central area is driven to the included angle and border area by injected water and then produced at the production stage. Finally, the oil recovery in the central area rises by 5.2% and in the noncentral area is also increased in different levels. The AIP process can realize the alternative change of reservoir pressure, change the distribution of flow field, and enlarge the swept area by injected water. To sum it up, the AIP process is an effective method to improve the oil recovery in complex fault-block reservoir by water flooding.

Influence of Deposition Characteristics in the Heavy Oilfield Development Stage

2013 ◽  
Vol 734-737 ◽  
pp. 373-376
Author(s):  
Xiao Meng Fang ◽  
Shuai Guan ◽  
Yan Ping Ma
Keyword(s):  
River Sediments ◽  
Development Stage ◽  
Delta Front ◽  
Fan Delta ◽  
Well Spacing ◽  
Well Pattern ◽  
Remaining Oil ◽  
Sedimentary Microfacies ◽  
The Impact ◽  
Oilfield Development

III oil formation of He3 section of block 1 in Jinglou Oilfield has entered the mid-late stage of oilfield development after years of steam huff and puff production. The distribution of remaining oil is scattered. This paper combines the data of core, well logging, seismic and development performance to analyze the reservoir heterogeneity. It reveals the impact on oilfield development. The area is mainly fine sandstone, siltstone and inequigranular sandstone, belonging to the river sediments, the development of fan delta and fan delta front subfacies. The heterogeneity of reservoirs and sedimentary microfacies are closely related, with moderate - strong. Well spacing near the larger region between the well and well pattern is not perfect in southern area and fault is the main purpose of tapping the potential of remaining oil in the next area.

Scheme to Tap Remaining Oil Potential in Poor Pay Zones

2013 ◽  
Vol 734-737 ◽  
pp. 1257-1261
Author(s):  
Ji Cheng Zhang ◽  
Shu Hong Zhao ◽  
Jin Yu Lan ◽  
Kao Ping Song
Keyword(s):  
Oil Recovery ◽  
Water Flooding ◽  
Oil Distribution ◽  
Well Pattern ◽  
Remaining Oil ◽  
Tertiary Oil Recovery ◽  
Well Pattern Optimization ◽  
Numerical Simulation Technique ◽  
Production Target

This paper analyzed the balanced flood performance of various layers and the remaining oil distribution through numerical simulation technique. It shows that, the main remaining oil type of intended layers is caused by voidage-injection imperfection. Considering the needs of the follow-up infill well pattern and tertiary oil recovery, we decide to maintain the relative independence and integrity of each well network without disturbing the pattern configuration and the mining exploit object of various sets of well pattern. Finally we confirm to perforate adding the first infill wells of intended layers to consummate the water flooding regime. Through analyzing the production target of different well pattern optimization programs relatively, it shows that the best program has regular well pattern and large drilled thickness.

scholarly journals Countermeasures to Decrease Water Cut and Increase Oil Recovery from High Water Cut, Narrow-Channel Reservoirs in Bohai Sea

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Gaocheng Feng ◽  
Yuhui Zhou ◽  
Weiying Yao ◽  
Lingtong Liu ◽  
Zhao Feng ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Bohai Sea ◽  
High Water ◽  
Narrow Channel ◽  
Optimization Strategy ◽  
Well Pattern ◽  
Remaining Oil ◽  
High Water Cut ◽  
Water Cut ◽  
Well Pattern Optimization

Most multilayer sandstone reservoirs in the Bohai Sea have already entered the middle or high water cut production stage with large amounts of remaining oil being scattered distributed. Therefore, there is an urgent need to find a suitable countermeasure to reduce water cut and increase oil recovery. In this study, taking the narrow-channel reservoirs in the M oilfield as an example, we qualitatively described the sand body scale and the contact relationships between different sand bodies, in addition to carefully analyzing the material base and remaining oil distribution characteristics. Accordingly, we proposed a countermeasure based on the injection-production structural adjustment to reduce water cut and increase oil recovery from high water cut, narrow-channel reservoirs. Herein, three optimization strategies were developed based on the proposed development mode: a seepage field optimization strategy was developed based on the quantified injection-production index; a well pattern optimization strategy for narrow-channel reservoirs was developed to overcome the production energy refueling problem; an injection-production measure optimization strategy was developed to tap the different types of remaining oil. Additionally, the well pattern optimization and injection-production optimization strategies were integrated to optimize and adjust the seepage field system. The findings reported herein this paper help understand the development of similar offshore oilfields with a high water cut.

scholarly journals The optimization of pre-slug size in CO2-N2 compound flooding

2020 ◽  
Vol 206 ◽  
pp. 02017
Author(s):  
Taoping Chen ◽  
Wen Sun ◽  
Guofang Zhang ◽  
Fuping Wang
Keyword(s):  
Oil Recovery ◽  
Oil And Gas ◽  
Element Model ◽  
Low Permeability ◽  
Experimental Conditions ◽  
Well Spacing ◽  
Well Pattern ◽  
Complete Miscibility ◽  
Enhance Oil Recovery ◽  
The Impact

In order to enhance oil recovery in low and ultra-low permeability layer, both of the numerical simulation and physical model experiment have been researched. First, the dynamic distribution of CO1 and N1 in the oil and gas phase in the CO2-N2 compound flooding process was numerically simulated by using the long slim-tube model. The results show that the CO2 slug should have at least 0.3 PV to prevent the impact of N2 channeling effectively. Second, under the experimental conditions of complete miscibility of CO2-crude oil, the two types of natural cores including low and ultra-low permeability, respectively, are used for experimental study on oil displacement. The results confirm that CO2-N2 compound flooding with 0.3 PV CO2 pre-slug can achieve a good result. Finally, a five-point well pattern element model is established by CMG. The recovery and the gas cost of per ton of oil are calculated respectively for CO2-N2 compound flooding and full CO2 flooding at 300 m well spacing of low and ultra-low permeability layer. According to the simulation results, the optimal CO2 pre-slug size in CO2-N2 compound flooding under the condition of low and ultra-low permeability layer five-point well pattern is 0.4 PV.

A New well Pattern for Enhancing Waterflood Performance of Ultra-Low Permeability Reservoir in Changqing Oilfield

2013 ◽  
Vol 318 ◽  
pp. 501-506
Author(s):  
Zhang Zhang ◽  
Shun Li He ◽  
Hai Yong Zhang
Keyword(s):  
Oil Recovery ◽  
Early Stage ◽  
Water Injection ◽  
Field Application ◽  
Low Permeability ◽  
Great Ability ◽  
Low Permeability Reservoir ◽  
Well Spacing ◽  
Well Pattern ◽  
The One

Because the development of ultra-low permeability reservoir is relative to fracture system, suitable well pattern arrangement is very significant for effective flooding management. There were three kinds of well pattern used to waterflood in Changqing oilfield: square inverted nine-spot, rhombus inverted nine-spot and rectangular five-spot pattern, according to the degree of fracture growth. In view of the defects of these well patterns in the development of ultra-low permeability reservoirs, a new well spacing concept is developed. Numerical simulations are carried out to illustrate the adaptability and strong points of this new well pattern. For this well pattern, on the one hand, the distance between producers and injectors along the fracture direction is widened and thus massive fracturing can be conducted to enhance oil productivity and water injection, and on the other hand, a high producer/injector ratio ensures high oil recovery rate in early stage. Besides, this new well pattern has a great ability of adjustment. Field application showed a remarkably well producing performance.

Research and Application of Tapping Potential Remaining Oil of Low Permeability Reservoir in Hei47 Block, Jilin Oilfield

2013 ◽  
Vol 663 ◽  
pp. 753-758 ◽  
Author(s):  
Fang Ding ◽  
Xu Yang
Keyword(s):  
Study Design ◽  
Water Injection ◽  
High Water ◽  
Injection Wells ◽  
Well Spacing ◽  
Well Pattern ◽  
Remaining Oil ◽  
High Water Cut ◽  
Water Cut ◽  
High Place

At present, Hei47 block has already entered high water cut period, and it exists many problems, such as imbalance producing reserves, serious water flooded in main small layer, imperfect injection-production well spacing and so on. Aiming at these problems, this paper analyzed from two aspects of the potential: the first is the potentiality of well pattern thickening which would analyze the reasons of the remaining oil enrichment through four different imperfect patterns, the paper proposes different schemes. For example, this study design new wells in the injection-production incongruous area; As for the area without the control of well net, for example, the study design a horizontal well near the fault where concentrated much remaining oil, and the production conditions are good; The second is making some modification measures in high water cut layer, and perforating other potential small layers, in the light of the wells in low location and is high water cut can be considered to transfer to injection wells. Structural reservoir high-yielding well mainly concentrated in the structural high place, flooded well in the low position, this area is suitable for edge water injection.

scholarly journals Pore-Scale Simulation of Particle Flooding for Enhancing Oil Recovery

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2305
Author(s):  
Xiangbin Liu ◽  
Le Wang ◽  
Jun Wang ◽  
Junwei Su
Keyword(s):  
Oil Recovery ◽  
Flow Behavior ◽  
Ct Scanning ◽  
Water Flooding ◽  
Pore Scale ◽  
Simulation Techniques ◽  
Three Phase ◽  
Remaining Oil ◽  
Three Phase Flow ◽  
Displacement Force

The particles, water and oil three-phase flow behaviors at the pore scale is significant to clarify the dynamic mechanism in the particle flooding process. In this work, a newly developed direct numerical simulation techniques, i.e., VOF-FDM-DEM method is employed to perform the simulation of several different particle flooding processes after water flooding, which are carried out with a porous structure obtained by CT scanning of a real rock. The study on the distribution of remaining oil and the displacement process of viscoelastic particles shows that the capillary barrier near the location with the abrupt change of pore radius is the main reason for the formation of remaining oil. There is a dynamic threshold in the process of producing remaining oil. Only when the displacement force exceeds this threshold, the remaining oil can be produced. The flow behavior of particle–oil–water under three different flooding modes, i.e., continuous injection, alternate injection and slug injection, is studied. It is found that the particle size and the injection mode have an important influence on the fluid flow. On this basis, the flow behavior, pressure characteristics and recovery efficiency of the three injection modes are compared. It is found that by injecting two kinds of fluids with different resistance increasing ability into the pores, they can enter into different pore channels, resulting in the imbalance of the force on the remaining oil interface and formation of different resistance between the channels, which can realize the rapid recovery of the remaining oil.

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