A Fuzzy Method to Judge Water Passages with Ineffective Injection-Production for Heterogeneous Sandstone Reservoir

2012 ◽  
Vol 524-527 ◽  
pp. 1306-1309 ◽  
Author(s):  
Peng Xiao Sun
Keyword(s):  
Mathematical Model ◽  
Fuzzy Theory ◽  
Water Injection ◽  
High Water ◽  
Water Flooding ◽  
Profile Control ◽  
Production Wells ◽  
High Water Cut ◽  
Water Cut ◽  
Swept Volume

In this paper, the indexes have been determined for identifying ineffective injection production circulation and corresponding mathematical model was constructed with fuzzy theory. Application examples show that this method is simple, fast and accurate. For high and superhigh water cut oilfields, because of the long-term erosion of injected water, there are some high penetrative channels between the injection and production wells, resulting in most injected water along the channel to cause the invalid injection and production, for which it is hard to increase water flooding swept volume, causing flooding and high water cut well and reducing oil production. To improve the effectiveness of water injection to achieve stable yields, it is important to take the measures of ineffective injection-production wells profile control, plugging and so on for fast and accurate identifying ineffective injection-production wells. To that end, this paper applied fuzzy theory to establishing the mathematical model for identifying ineffective injection-production wells.

Investigation on Circulating Path of Injected Water for High Water-Cut Oilfield

2014 ◽  
Vol 1073-1076 ◽  
pp. 2201-2204
Author(s):  
Sui Ting Zhao ◽  
Qi Li ◽  
Xiao Ru He ◽  
Kao Ping Song ◽  
Ji Cheng Zhang
Keyword(s):  
Mathematical Model ◽  
Fuzzy Theory ◽  
Water Injection ◽  
High Water ◽  
Water Flooding ◽  
Profile Control ◽  
Production Wells ◽  
High Water Cut ◽  
Water Cut ◽  
Swept Volume

In this paper, the indexes have been determined for identifying ineffective injection-production circulation and corresponding mathematical model was constructed with fuzzy theory. Application examples show that this method is simple, fast and accurate. For high and extra-high water cut oilfields, because of the long-term erosion of injected water, there are some high penetrative channels between the injection and production wells, resulting in most injected water along the channel to cause the invalid injection and production, for which it is hard to increase water flooding swept volume, causing flooding and high water cut well and reducing oil production. To improve the effectiveness of water injection to achieve stable yields, it is important to take the measures of ineffective injection-production wells profile control, plugging and so on for fast and accurate identifying ineffective injection-production wells. To that end, this paper applied fuzzy theory to establishing the mathematical model for identifying ineffective injection-production wells.

scholarly journals Techniques for improving the water-flooding of oil fields during the high water-cut stage

2019 ◽  
Vol 74 ◽  
pp. 69 ◽  
Author(s):  
Kuiqian Ma ◽  
Ao Li ◽  
Shuhao Guo ◽  
Jieqiong Pang ◽  
Yongchao Xue ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Reduction Rate ◽  
High Water ◽  
Water Flooding ◽  
Variable Intensity ◽  
Remaining Oil ◽  
High Water Cut Stage ◽  
High Water Cut ◽  
Water Cut

The multi-layer co-exploitation method is often used in offshore oilfields because of the large spacing between the injection and production wells. As oilfields gradually enter the high water-cut stage, the contradiction between the horizontal and vertical directions becomes more prominent, and the distribution of the remaining oil is more complex. Oilfields are facing unprecedented challenges in further enhancing oil recovery. Using oilfield A, which is in the high water-cut stage, as the research object, we compiled a detailed description of the remaining oil during the high water-cut stage using the information collected during the comprehensive adjustment and infilling of the oilfield. In addition various techniques for tapping the potential reservoir, stabilizing the oil, and controlling the water were investigated. A set of key techniques for the continuous improvement of the efficiency of water injection after comprehensive adjustment of high water-cut fields was generated. Based on the determined configuration of the offshore deltaic reservoir, a set of detailed descriptive methods and tapping technology for extracting the remaining oil in the offshore high water-cut oilfield after comprehensive adjustment was established. By considering the equilibrium displacement and using a new quantitative characterization method that includes displacement, a new technique for determining the quantity of water that needs to be injected into a stratified injection well during the high water-cut stage was established. Based on the principle of flow field intensity reconfiguration, a linear, variable-intensity, alternating injection and withdrawal technique was proposed. With the application of this series of techniques, the increase in the water content was controlled to within 1%, the natural reduction rate was controlled to within 9%, and the production increased by 1.060 × 107 m3.

scholarly journals Mechanism of Enhanced Oil Recovery for In-Depth Profile Control and Cyclic Waterflooding in Fractured Low-Permeability Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Daiyin Yin ◽  
Wei Zhou
Keyword(s):  
Enhanced Oil Recovery ◽  
Depth Profile ◽  
Oil Recovery ◽  
Water Injection ◽  
High Water ◽  
Low Permeability ◽  
Profile Control ◽  
High Water Cut ◽  
Water Cut ◽  
Low Permeability Reservoirs

When fractured low-permeability reservoirs enter a high water cut period, injected water always flows along fractures, water cut speeds increase rapidly, and oil production decreases quickly in oil wells. It is difficult to further improve the oil recovery of such fractured low-permeability reservoirs. In this paper, based on the advantages of in-depth profile control and cyclic water injection, the feasibility of combining deep profile control with cyclic water injection to improve oil recovery in fractured low-permeability reservoirs during the high water cut stage was studied, and the mechanisms of in-depth profile control and cyclic waterflooding were investigated. According to the characteristics of reservoirs in Zone X, as well as the fracture features and evolution mechanisms of the well network, an outcrop plate fractured core model that considers fracture direction was developed, and core displacement experiments were carried out by using the HPAM/Cr3+ gel in-depth profile control system. The enhanced oil recovery of waterflooding, cyclic water injection, and in-depth profile control, as well as a combination of in-depth profile control and cyclic water injection, was investigated. Moreover, variations in the water cut degree, reserve recovery percentage, injection pressure, fracture and matrix pressure, and water saturation were monitored. On this basis, the mechanism of enhanced oil recovery based on the combined utilization of in-depth profile control and cyclic waterflooding methods was analyzed. The results show that in-depth profile control and cyclic water injection can be synchronized to further increase oil recovery. The recovery ratio under the combination of in-depth profile control and cyclic water injection was 1.9% higher than that under the in-depth profile control and 5.6% higher than that under cyclic water injection. The combination of in-depth profile control and cyclic water injection can increase the reservoir pressure; therefore, the fluctuation of pressure between the matrix and its fractures increases, more crude oil flows into the fracture, and the oil production increases.

A Fuzzy Method to Evaluate Remaining Oil Potentiality of PI Group

2013 ◽  
Vol 734-737 ◽  
pp. 1131-1134
Author(s):  
Jian Zhong Liu ◽  
Jin Cheng Xu
Keyword(s):  
Fuzzy Theory ◽  
Water Injection ◽  
Influence Factors ◽  
Sedimentary Facies ◽  
High Water ◽  
Potential Measurement ◽  
Oil Distribution ◽  
Remaining Oil ◽  
High Water Cut ◽  
Water Cut

The remaining oil distribution and its potential evaluation are the keys to the well network adjustments and comprehensive potential exploration on the later stage production. In view of the vagueness of the influence factors of remaining oil potentiality, a set of quantitative evaluate method about how to suit remaining oil potentiality of heavy oil reservoir at high water-cut stage is established. Six factors are taken into consideration, including oil saturation, reservoir thickness, permeability, porosity, water injection distance and sedimentary facies. First, make sure the evaluate criterion and the influence weight of a single effect factor. And then, use the fuzzy theory to calculate the latent capacity of the block, comprehending many factors. In the end, certain the foundation of remaining oil potentialities according to the value of the latent capacity. Using this method, remaining oil potentiality of the east of Beierxi is calculated at high water cut period. This provides a theoretical guide to formulation and implementation of the in-situ potential measurement.

The Research of Water Flooding Measures in Late High Water Cut Period of Secondary Reservoirs

2014 ◽  
Vol 703 ◽  
pp. 308-311
Author(s):  
Kao Ping Song ◽  
Cheng Cheng Wang ◽  
Cheng Fu ◽  
Xiao Hui Wu
Keyword(s):  
Numerical Simulation ◽  
Water Injection ◽  
High Water ◽  
Water Flooding ◽  
Injection Timing ◽  
Recovery Efficiency ◽  
Geological Characteristics ◽  
High Water Cut Stage ◽  
High Water Cut ◽  
Water Cut

D aqing o ilfield is in high water cut stage and always appears two phenomenon called "two speeds" and "two low". Based on the geological characteristics of the block, the current exploration wells arrangement and producing dynamics, two sets programs of water injection intensity and water injection timing were designed. Through the numerical simulation prediction of the two sets of 16 programs, the optimization results are 9 injection intensity and 93% of water cut. The cumulative oil producing capacity is 1402.41×104t and the cumulative increasing oil capacity is 6.26×104t and the increasing value of the recovery efficiency in Secondary oil layer is 1.33% when the water cut is 98%.

scholarly journals Optimization of MBR Field Integrated Production Model

PETRO ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 45
Author(s):  
Rizky Rezha Fauzi ◽  
Djoko Sulistyanto ◽  
Ghanima Yasmaniar
Keyword(s):  
Water Injection ◽  
Oil Production ◽  
High Water ◽  
Production Model ◽  
East Kalimantan ◽  
Production Wells ◽  
High Water Cut ◽  
Water Cut ◽  
Plant Capacity ◽  
Bean Size

<p>MBR Field is an onshore field located at East Kalimantan. In this field, there are five clusters with 2 main stations and 1 supporting station. With the current pipe flow conditions, this field has several constraints which are ESP maximum motor loads, ESP maximum frequencies, and current maximum water injection plant capacity. First, modeling is done with deviations of less than 10 percent to reach matching conditions in several parameters such as upstream pressure, downstream pressure, liquid rate, water rate, oil rate, and gas rate. Afterward, the first optimization is done by increasing the ESP frequency, increasing choke bean size, and shutting-in relatively low oil production wells with high water cut. But due to the water production is almost exceeding the water injection plant capacity, then the second optimization is done. The second optimization is done by increasing choke bean size and shutting-in relatively low oil production wells with high water cut. Each optimization is then followed by an analysis of pressure and flowrates alterations and the existence of backpressure in unoptimized wells.</p>

Innovations of Gas Lift in Prolific, Long-perforations, and Multilayered Wells, Case Study in Sudan

2016 ◽  
Author(s):  
Xueqing Tang ◽  
Lirong Dou ◽  
Ruifeng Wang ◽  
Jie Wang ◽  
Shengbao Wang ◽  
...  
Keyword(s):  
High Water ◽  
Water Breakthrough ◽  
Start Up ◽  
Production Wells ◽  
Decline Curves ◽  
High Water Cut ◽  
Water Cut ◽  
Gas Lift

ABSTRACT Jake field, discovered in July, 2006, contains 10 oil-producing and 12 condensate gas-producing zones. The wells have high flow capacities, producing from long-perforation interval of 3,911 ft (from 4,531 to 8,442 ft). Production mechanisms include gas injection in downdip wells and traditional gas lift in updip, zonal production wells since the start-up of field in July, 2010. Following pressure depletion of oil and condensate-gas zones and water breakthrough, traditional gas-lift wells became inefficient and dead. Based on nodal analysis of entire pay zones, successful innovations in gas lift have been made since March, 2013. This paper highlights them in the following aspects: Extend end of tubing to the bottom of perforations for commingled production of oil and condensate gas zones, in order to utilize condensate gas producing from the lower zones for in-situ gas lift.Produce well stream from the casing annulus while injecting natural gas into the tubing.High-pressure nitrogen generated in-situ was used to kick off the dead wells, instead of installation of gas lift valves for unloading. After unloading process, the gas from compressors was injected down the tubing and back up the casing annulus.For previous high water-cut producers, prior to continuous gas lift, approximately 3.6 MMcf of nitrogen can be injected and soaked a couple of days for anti-water-coning.Two additional 10-in. flow lines were constructed to minimize the back pressure of surface facilities on wellhead. As a consequence, innovative gas-lift brought dead wells back on production, yielding average sustained liquid rate of 7,500 bbl/d per well. Also, the production decline curves flattened out than before.

scholarly journals Qualitative interpretation method of water flooding in independent off surface reservoir of Lamadian Oilfield

2020 ◽  
Vol 165 ◽  
pp. 03039
Author(s):  
Li Hong Cui
Keyword(s):  
Outer Surface ◽  
High Water ◽  
Water Flooding ◽  
Qualitative Interpretation ◽  
Remaining Oil ◽  
High Water Cut ◽  
Water Cut ◽  
Surface Reservoir ◽  
Interpretation Method ◽  
Thick Layers

With Lamadian Oilfield entering the late stage of ultra-high water cut, the number of thick layers in water drive is becoming less and less, so it is imperative to study the remaining oil in thin difference reservoir. For the thin difference reservoir, the independent off surface reservoir has naturally become an important research object [1]. It is necessary to study the waterflooding condition of the independent outer surface reservoirs to find out the producing law of the thin difference reservoirs at present. In this paper, we mainly use thewater washing data of independent outer surface reservoir and core data of sidewall of coring well to find the water flooding interpretation law of independent outer surface reservoir.This paper focuses on the analysis of the characteristics of the electric logging curve of the independent off surface reservoir after water flooding, and summarizes a set of qualitative interpretation methods suitable for the independent off surface reservoir of Lamadian oilfield. This method can improve the accuracy of waterflooded layer interpretation and meet the needs of remaining oil potential tapping in the later stage of ultra-high water cut.

scholarly journals New Waterflooding Characteristic Curves Based on Cumulative Water Injection

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhiwang Yuan ◽  
Zhiping Li ◽  
Li Yang ◽  
Yingchun Zhang
Keyword(s):  
Characteristic Curve ◽  
Water Injection ◽  
Material Balance ◽  
Oil Production ◽  
High Water ◽  
Difficult Problem ◽  
Prediction Errors ◽  
High Water Cut Stage ◽  
High Water Cut ◽  
Water Cut

When a conventional waterflooding characteristic curve (WFCC) is used to predict cumulative oil production at a certain stage, the curve depends on the predicted water cut at the predicted cutoff point, but forecasting the water cut is very difficult. For the reservoirs whose pressure is maintained by water injection, based on the water-oil phase seepage theory and the principle of material balance, the equations relating the cumulative oil production and cumulative water injection at the moderately high water cut stage and the ultrahigh water cut stage are derived and termed the Yuan-A and Yuan-B curves, respectively. And then, we theoretically analyze the causes of the prediction errors of cumulative oil production by the Yuan-A curve and give suggestions. In addition, at the ultrahigh water cut stage, the Yuan-B water cut prediction formula is established, which can predict the water cut according to the cumulative water injection and solve the difficult problem of water cut prediction. The application results show Yuan-A and Yuan-B curves are applied to forecast oil production based on cumulative water injection data obtained by the balance of injection and production, avoiding reliance on the water cut forecast and solving the problems of predicting the cumulative oil production of producers or reservoirs that have not yet shown the decline rule. Furthermore, the formulas are simple and convenient, providing certain guiding significance for the prediction of cumulative oil production and water cut for the same reservoir types.

scholarly journals Microscopic Determination of Remaining Oil Distribution in Sandstones With Different Permeability Scales Using Computed Tomography Scanning

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Yongfei Yang ◽  
Haiyuan Yang ◽  
Liu Tao ◽  
Jun Yao ◽  
Wendong Wang ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Oil Recovery ◽  
Distribution Patterns ◽  
High Water ◽  
Water Flooding ◽  
Oil Distribution ◽  
Computed Tomography Scanning ◽  
Remaining Oil ◽  
High Water Cut ◽  
Water Cut

To investigate the characteristics of oil distribution in porous media systems during a high water cut stage, sandstones with different permeability scales of 53.63 × 10−3 μm2 and 108.11 × 10−3 μm2 were imaged under a resolution of 4.12 μm during a water flooding process using X-ray tomography. Based on the cluster-size distribution of oil segmented from the tomography images and through classification using the shape factor and Euler number, the transformation of the oil distribution pattern in different injection stages was studied for samples with different pore structures. In general, the distribution patterns of an oil cluster continuously change during water injection. Large connected oil clusters break off into smaller segments. The sandstone with a higher permeability (108.11 × 10−3 μm2) shows the larger change in distribution pattern, and the remaining oil is trapped in the pores with a radius of approximately 7–12 μm. Meanwhile, some disconnected clusters merge together and lead to a re-connection during the high water cut period. However, the pore structure becomes compact and complex, the residual nonwetting phase becomes static and is difficult to move; and thus, all distribution patterns coexist during the entire displacement process and mainly distribute in pores with a radius of 8–12 μm. For the pore-scale entrapment characteristics of the oil phase during a high water cut period, different enhance oil recovery (EOR) methods should be considered in sandstones correspondent to each permeability scale.

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