Pilot Project: Application of Multi-Component Thermal Fluid Stimulation on Shallow Heavy Oil Reservoir in Kazakhstan

2021 ◽  
Author(s):  
Leihao Yi ◽  
Xin Hua ◽  
Wenlong Guan ◽  
Shiguo Xu ◽  
Ziyi Zhang ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Late Stage ◽  
Free Water ◽  
Oil Production ◽  
Economic Benefits ◽  
Production Performance ◽  
Combustion Mechanism ◽  
Oil Reservoir ◽  
Heavy Oil Reservoir ◽  
Water Cut

Abstract Cyclic steam simulation (CSS) was widely used to recover heavy oil in shallow reservoirs in Kazakhstan. In the late stage of CSS in M oilfield, the performance of this CSS project was poor with high water cut and low oil steam ratio (OSR), indicating low economic benefit. The multi-component thermal fluid (MTF) stimulation trial has been conducted there since March 2018 to evaluate the feasibility of this technology. This paper introduces the field experience and the production performance of MTF stimulation. Results are from 32 cycles of MTF stimulations in 23 wells, most of which had completed their 4 cycles of CSS before. MTF technology is based on a high-pressure jet combustion mechanism, generating a mixture of nitrogen, carbon dioxide and vapor (MTF) under a sealed combustion condition. The mixture fluid provides a significant enhancement through a synergistic effect in the reservoir. The soaking and recovery process are the same as the conventional steam stimulation, meanwhile the requirements for completion and wellbore structure are the same as well. By the time of statistic, average cyclic OSR reaches 2.19 from 0.49 of last CSS cycle. Average water cut declines from 90% to 40% and daily oil production rises from 22 bbls to 33 bbls. Free water is almost invisible in the produced fluid, instead, a stable quasi-monophasic flow has been presented even at low temperatures. This effectively increases the fluidity and dilatancy of crude oil, and greatly replenishes the elastic energy of the formation. Meanwhile, with all components injected into the formation, MTF stimulation achieves significant reduction in carbon emissions. Although this is a pilot test, considerable economic benefits have been achieved with the increase of oil production efficiency. MTF stimulation brings an additional profit of USD 4.4 million for the first year under conditions of local material's cost. This successful pilot demonstrates that MTF stimulation may play an important role at late stage of CSS, even it has its own prospect in an initial heavy oil reservoir development. In the meantime, this pilot experience can be used as a reference for other similar reservoirs’ development.

Nitrogen Foam Anti-Edge Water-Incursion Technology for Heavy Oil Reservoir with Edge Water

2013 ◽  
Vol 827 ◽  
pp. 66-71 ◽  
Author(s):  
Jie Xiang Wang ◽  
Teng Fei Wang ◽  
ZeXia Fan
Keyword(s):  
Heavy Oil ◽  
Field Tests ◽  
Oil Production ◽  
Oil Reservoir ◽  
Steam Flooding ◽  
Nitrogen Foam ◽  
Single Well ◽  
Heavy Oil Reservoir ◽  
Water Cut ◽  
Steam Stimulation

The steam stimulation is a main method to develop the heavy oil reservoir. However, the huff-puff wells will be water-flooded quickly if the reservoir has edge water, and the oil production level will decrease sharply. An experimental device, which can simulate edge water and steam stimulation process, was designed according to the feature of Henan heavy oil reservoir with edge water on the basis of steam flooding device, and the effect factors and application conditions of nitrogen foam anti-edge water-incursion technology were researched. The results show that the anti-edge water-incursion technology is suitable for the heavy oil reservoir with a medium energy edge water, and a better foam plugging will be got if the technology is applied at the time of serious water-flooded. The optimum injection pattern of the technology is a N2 slug first, followed by a nitrogen foam slug, and then the steam slug. Field tests were proceeded on the basis of experiment results and field experience, the operation success rate is 100%, the average drainage period reduces by 0.7d, the average cycle water cut reduces by 23%, the average cycle oil production increases by 2 times, and the average single-well oil-steam ratio increases by 0.25. So the technology can reduce water cut and increase oil production significantly, and the target of edge water inhibition is achieved.

Superiority of Superheated Steam Flooding in Development of High Water-Cut Heavy Oil Reservoir

2012 ◽  
Vol 616-618 ◽  
pp. 992-995
Author(s):  
An Zhu Xu ◽  
Long Xin Mu ◽  
Xiang Hong Wu ◽  
Zi Fei Fan ◽  
Lun Zhao
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
High Water ◽  
Viscosity Reduction ◽  
Saturated Steam ◽  
Oil Reservoir ◽  
Heavy Oil Reservoir ◽  
High Water Cut ◽  
Water Cut ◽  
Steam Stimulation

The dryness of superheated steam is 100% and it exists in the form of pure steam whose properties are like ideal gas. When the steam has a large degree of superheat, it may take a relatively long time to cool, during which time the steam is releasing very little energy and transmitted long distances. The heating radius of superheated steam in the formation is 5-10m larger than saturated steam. In the heating area of superheated steam, the comprehensive effects by superheated steam (crude oil viscosity reduction, improved flow environment, changes in rock wettability and improved oil displacement efficiency, etc.) is much higher than that of saturated steam. Superheated steam stimulation in Kenkyak high water cut heavy oil reservoir pilot test results showed that the average daily oil production of single well by superheated steam stimulation was 2-4 times than that of saturated steam stimulation. Superheated steam is more effective to heat water-invaded oil reservoir than saturated steam.

scholarly journals A well selection method of CO2 huff and puff in heavy oil reservoir with edge and bottom water based on water cut

2021 ◽  
Vol 329 ◽  
pp. 01069
Author(s):  
Jia Wang ◽  
Tongjing Liu ◽  
Hengyu Shi ◽  
Pengxiang Diwu ◽  
Jian Zhou ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Bottom Water ◽  
Selection Method ◽  
Evaluation Index ◽  
Oil Reservoir ◽  
Effective Measure ◽  
Potential Wells ◽  
Water Based ◽  
Heavy Oil Reservoir ◽  
Water Cut

The water cut of heavy oil reservoir with edge and bottom water rises rapidly and the recovery degree of crude oil is low. CO2 huff and puff is an effective measure to improve the recovery of this kind of reservoir, and scientific well selection is the premise of the measure effect. Because the existing well selection methods of CO2 huff and puff in heavy oil reservoir with edge and bottom water mostly take the oil increase of oil well as the evaluation index, ignoring the characterization of well water cut after huff and puff, it is unable to accurately screen all potential wells. Therefore, a quantitative well selection method of CO2 huff and puff in heavy oil reservoir with edge and bottom water based on water cut is proposed. The method is based on fuzzy comprehensive evaluation theory and analytic hierarchy process, and takes the water cut after CO2 huff and puff as the evaluation index. Several groups of typical models are designed to screen the sensitive factors and laws of CO2 huff and puff well selection in heavy oil edge and bottom water reservoir from three aspects of geology, water production law and technology. Than the judgment matrix is established. There is little interference from human factors in the process of well selection, and the rationality of the method has been verified by the effect of field actual well measures. This method is helpful to improve the well selection method system of CO2 huff and puff in this kind of reservoir, and is a reasonable supplement to the existing well selection method which takes the oil increment as the only evaluation index.

An Innovated Water Shutoff Technology in Offshore Carbonate Reservoir

2021 ◽  
Author(s):  
Yong Yang ◽  
Xiaodong Li ◽  
Changwei Sun ◽  
Yuanzhi Liu ◽  
Renkai Jiang ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Bottom Water ◽  
High Water ◽  
Carbonate Reservoir ◽  
Oil Reservoir ◽  
Water Production ◽  
Water Shutoff ◽  
Water Breakthrough ◽  
Heavy Oil Reservoir ◽  
Water Cut

Abstract The problem of water production in carbonate reservoir is always a worldwide problem; meanwhile, in heavy oil reservoir with bottom water, rapid water breakthrough or high water cut is the development feature of this kind of reservoir; the problem of high water production in infill wells in old reservoir area is very common. Each of these three kinds of problems is difficult to be tackled for oilfield developers. When these three kinds of problems occur in a well, the difficulty of water shutoff can be imagined. Excessive water production will not only reduce the oil rate of wells, but also increase the cost of water treatment, and even lead to well shut in. Therefore, how to solve the problem of produced water from infill wells in old area of heavy oil reservoir with bottom water in carbonate rock will be the focus of this paper. This paper elaborates the application of continuous pack-off particles with ICD screen (CPI) technology in infill wells newly put into production in brown field of Liuhua, South China Sea. Liuhua oilfield is a biohermal limestone heavy oil reservoir with strong bottom water. At present, the recovery is only 11%, and the comprehensive water cut is as high as 96%. Excessive water production greatly reduces the hydrocarbon production of the oil well, which makes the production of the oilfield decrease rapidly. In order to delay the decline of oil production, Liuhua oilfield has adopted the mainstream water shutoff technology, including chemical and mechanical water shutoff methods. The application results show that the adaptability of mainstream water shutoff technology in Liuhua oilfield needs to be improved. Although CPI has achieved good water shutoff effect in the development and old wells in block 3 of Liuhua oilfield, there is no application case in the old area of Liuhua oilfield which has been developed for decades, so the application effect is still unclear. At present, the average water cut of new infill wells in the old area reaches 80% when commissioned and rises rapidly to more than 90% one month later. Considering that there is more remaining oil distribution in the old area of Liuhua oilfield and the obvious effect of CPI in block 3, it is decided to apply CPI in infill well X of old area for well completion. CPI is based on the ICD screen radial high-speed fluid containment and pack-off particles in the wellbore annulus to prevent fluid channeling axially, thus achieving well bore water shutoff and oil enhancement. As for the application in fractured reef limestone reservoir, the CPI not only has the function of wellbore water shutoff, but also fills the continuous pack-off particles into the natural fractures in the formation, so as to achieve dual water shutoff in wellbore and fractures, and further enhance the effect of water shutoff and oil enhancement. The target well X is located in the old area of Liuhua oilfield, which is a new infill well in the old area. This target well with three kinds of water problems has great risk of rapid water breakthrough. Since 2010, 7 infill wells have been put into operation in this area, and the water cut after commissioning is 68.5%~92.6%. The average water cut is 85.11% and the average oil rate is 930.92 BPD. After CPI completion in well X, the water cut is only 26% (1/3 of offset wells) and the oil rate is 1300BPD (39.6% higher than that of offset wells). The target well has achieved remarkable effect of reducing water and increasing oil. In addition, in the actual construction process, a total of 47.4m3 particles were pumped into the well, which is equivalent to 2.3 times of the theoretical volume of the annulus between the screen and the borehole wall. Among them, 20m3 continuous pack-off particles entered the annulus, and 27.4m3 continuous pack-off particles entered the natural fractures in the formation. Through the analysis of CPI completed wells in Liuhua oilfield, it is found out that the overfilling quantity is positively correlated to the effect of water shutoff and oil enhancement.

Improvements of Superheated Steam Stimulation in Secondary Development of Heavy Oil Reservoir

2012 ◽  
Vol 524-527 ◽  
pp. 1450-1455
Author(s):  
An Zhu Xu ◽  
Xiang Hong Wu ◽  
Zi Fei Fan ◽  
Lun Zhao ◽  
Cheng Gang Wang
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Oil Production ◽  
Saturated Steam ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Heavy Oil Reservoir ◽  
Steam Stimulation

With superheated steam, there is no direct relationship between temperature and pressure, Therefore, at a particular pressure it is possible for superheated steam to exist at a wide range of temperatures higher than that of its saturated steam. The heat transfer coefficient is 1/150-1/250 as much as that of saturated steam during heat transferring, and it takes a relatively long time to cool, during which time the steam is releasing very little energy and transmitted long distances. The mechanisms of superheated steam stimulation are mainly pointed to the performance of crude oil viscosity reduced, flow environment improved, rock wettability changed, oil displacement efficiency improved. Physical simulation shows that oil displacement efficiency by superheated steam is 6-12% higher than that of saturated steam at the same temperature, and under the condition of carrying the same heat, superheated steam enlarged the heating radius by about 10m, oil steam ratio increased by 0.7. Superheated steam stimulation was put into Kazakstan’s heavy oil reservoir after two cycles of saturated steam stimulation. The average daily oil production was 2-4 times that of saturated steam stimulation, which improved heavy oil production effectively. The secondary heavy oil thermal recovery by superheated steam stimulation applied in marginal heavy oil reservoirs achieved satisfactory effect.

scholarly journals Comparison of Foamy Oil Behaviour between Shallow and Middepth Heavy Oil Reservoirs in the Orinoco Belt

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xingmin Li ◽  
Changchun Chen ◽  
Zhangcong Liu ◽  
Yongbin Wu ◽  
Xiaoxing Shi
Keyword(s):  
Heavy Oil ◽  
Oil And Gas ◽  
Production Performance ◽  
Oil Reservoirs ◽  
Recovery Factor ◽  
Oil Reservoir ◽  
Foamy Oil ◽  
Heavy Oil Reservoirs ◽  
Heavy Oil Reservoir ◽  
The Difference

Nowadays, extra heavy oil reservoirs in the Orinoco Heavy-Oil-Belt in Venezuela are exploited via cold production process, which present different production performance in well productivity and primary recovery factor. The purpose of this study is to investigate the causes for such differences with the aspect of foamy oil mechanism. Two typical oil samples were adopted from a shallow reservoir in western Junìn region and a middepth reservoir in eastern Carabobo region in the Belt, respectively. A depletion test was conducted using 1D sand-pack with a visualized microscopic flow observation installation for each of the oil samples under simulated reservoir conditions. The production performance, the foamy oil behaviour, and the oil and gas morphology were recorded in real time during the tests. The results indicated that the shallow heavy oil reservoir in the Belt presents a weaker foamy oil phenomenon when compared with the middepth one; its foamy oil behaviour lasts a shorter duration with a smaller scope, with bigger bubble size and less bubble density. The difference in foamy oil behaviour for those two types of heavy oil reservoir is caused by the difference in reservoir pressure, solution GOR, asphaltene content, etc. Cold production presents obvious features of three stages under the action of strong foamy oil displacement mechanism for the middepth heavy oil reservoir, which could achieve a more favourable production performance. In the contrary, no such obvious production characteristics for the shallow heavy oil reservoir are observed due to weaker foamy oil behaviour, and its primary recovery factor is 9.38 percent point lower than which of the middle heavy oil reservoirs.

scholarly journals Prediction of Conformance Control Performance for Cyclic-Steam-Stimulated Horizontal Well Using the XGBoost: A Case Study in the Chunfeng Heavy Oil Reservoir

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8161
Author(s):  
Zehao Xie ◽  
Qihong Feng ◽  
Jiyuan Zhang ◽  
Xiaoxuan Shao ◽  
Xianmin Zhang ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Heavy Oil ◽  
Oil Production ◽  
Horizontal Wells ◽  
Training Data ◽  
Gradient Boosting ◽  
Oil Reservoir ◽  
Conformance Control ◽  
Extreme Gradient Boosting ◽  
Heavy Oil Reservoir

Conformance control is an effective method to enhance heavy oil recovery for cyclic-steam-stimulated horizontal wells. The numerical simulation technique is frequently used prior to field applications to evaluate the incremental oil production with conformance control in order to ensure cost-efficiency. However, conventional numerical simulations require the use of specific thermal numerical simulators that are usually expensive and computationally inefficient. This paper proposed the use of the extreme gradient boosting (XGBoost) trees to estimate the incremental oil production of conformance control with N2-foam and gel for cyclic-steam-stimulated horizontal wells. A database consisting of 1000 data points was constructed using numerical simulations based on the geological and fluid properties of the heavy oil reservoir in the Chunfeng Oilfield, which was then used for training and validating the XGBoost model. Results show that the XGBoost model is capable of estimating the incremental oil production with relatively high accuracy. The mean absolute errors (MAEs), mean relative errors (MRE) and correlation coefficients are 12.37/80.89 t, 0.09%/0.059% and 0.99/0.98 for the training/validation sets, respectively. The validity of the prediction model was further confirmed by comparison with numerical simulations for six real production wells in the Chunfeng Oilfield. The permutation indices (PI) based on the XGBoost model indicate that net to gross ratio (NTG) and the cumulative injection of the plugging agent exerts the most significant effects on the enhanced oil production. The proposed method can be easily transferred to other heavy oil reservoirs, provided efficient training data are available.

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