Water-Injection Optimization for a Complex Fluvial Heavy-Oil Reservoir by Integrating Geological, Seismic, and Production Data

2009 ◽  
Vol 12 (06) ◽  
pp. 865-878 ◽  
Author(s):  
Xin Feng ◽  
Xian-Huan Wen ◽  
Bo Li ◽  
Ming Liu ◽  
Dengen Zhou ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Water Injection ◽  
Oil Production ◽  
Injection Rate ◽  
Production Data ◽  
Oil Reservoir ◽  
Reservoir Pressure ◽  
Channel Geometry ◽  
Heavy Oil Reservoir ◽  
Complex Channel

Summary BZ25-1s field in Bohai Bay, China, is characterized as a complex channelized fluvial reservoir in which small meandering channels were deposited at different geological times stacking and cross cutting each other. There are many isolated small reservoir systems following channel distributions. Early production showed steep pressure and production decline. Quick implementation of water injection was needed to arrest the fast production decline and to stabilize reservoir pressure. While designing the water-injection plan, we faced a number of challenges, such as high oil viscosity (˜200 cp), strong heterogeneity, poor reservoir connectivity, complex channel geometry, and irregular well patterns. A workflow integrating geological, well-log, seismic, and dynamic production data was developed to optimize a water injection plan for this field after a short production history. Focuses of this workflow are the selection of injection wells (converted from existing producers), timing of water injection, and the optimization of injection rates. Following the workflow, the optimal water-injection design for the areas around Platforms D and E was developed and quickly implemented within the first year of production. We started with a relatively small water-injection rate and gradually increased the injection rate to avoid the fast water breakthrough and yet to limit the pressure-decline rate. The responses from the water injection were very positive and resulted in stable reservoir pressure and increase of oil production. Before water injection, the production-decline rates were 26 and 47% in Platforms D and E, respectively. After 1 year of water injection, oil-production-decline rates in these two platforms were reduced to 19 and 14%, respectively. The responses of water injection for different well groups were analyzed in a timely fashion and adjustments to injection/production strategies were implemented accordingly. New information revealed from the water-injection response analysis was used to update the geological model to reduce the model uncertainty, as well as to adjust the water-injection strategies for better sweep efficiency. Our experiences showed that such dynamic adjustment of injection and production schedule is very important to achieve better water-injection efficiency for this heavy-oil reservoir with complex channel geometry.

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 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.

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.

Successful Cold Heavy Oil Production with Sand (CHOPS) Application in Massive Heavy Oil Reservoir in Sudan: A Case Study

2011 ◽  
Author(s):  
Ruifeng Wang ◽  
Xintao Yuan ◽  
Xueqing Tang ◽  
Xianghong Wu ◽  
Xinzheng Zhang ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Oil Production ◽  
Oil Reservoir ◽  
Heavy Oil Reservoir

Design and Practice of Steam Flooding on Anisotropic Heavy-Oil Reservoir with Edge-Bottom Water

2011 ◽  
Vol 71-78 ◽  
pp. 2049-2054 ◽  
Author(s):  
Jin Li Zhu ◽  
Liang Liang Jiang ◽  
Li Cheng Liu ◽  
Yu Qiu Lin
Keyword(s):  
Heavy Oil ◽  
Bottom Water ◽  
Thermal Recovery ◽  
Point Pattern ◽  
Oil Reservoir ◽  
Reservoir Pressure ◽  
Steam Flooding ◽  
Production Ratio ◽  
Well Pattern ◽  
Heavy Oil Reservoir

Liaohe block J is a super heavy oil reservoir with relatively strong anisotropy and active edge-bottom water condition. After more than two decades of huff and puff production, the block now reaches a low production rate period, and the local part of the block also encounters serious edge-bottom water invasion. Now steam flooding is used as a switching method to invert the production decline tendency. Applied with thermal recovery process and numerical simulation method, reservoir pressure at flooding conversion, pressure control in steam flooding, injection-production parameters and well pattern are used to optimize the key techniques of steam flooding design. The design results are as follows: the reservoir pressure at flooding conversion as well as during steam flooding process should be controlled below 5 Mpa; the unit volume steam injection rate is 1.65t/d.hm2.m and the bottom-hole steam quality of injecter is no less than 53%; the injection-production ratio is 1.1:1 and inversed 9 point pattern with a 83m well space is used. The steam flooding pilot has been carried out for more than 2 years and obtains favorable benefits.

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.

Methods Study on Gas Channeling of In Situ Combustion Development in Developed Heavy Oil Reservoir

2013 ◽  
Vol 316-317 ◽  
pp. 834-837
Author(s):  
Zong Zhan Xue ◽  
Deng Fa He ◽  
Xiao Heng Wang
Keyword(s):  
Heavy Oil ◽  
Injection Rate ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Reservoir Properties ◽  
In Situ Combustion ◽  
Heavy Oil Reservoirs ◽  
Heavy Oil Reservoir ◽  
Gas Channeling

Now in situ combustion became one of the ways for the developed heavy oil reservoirs to convert development pattern and improve recovery. After long time steam huff and puff development in heavy oil reservoir, it was obvious that there was a big change on the oil zones and reservoir properties and the reservoir heterogeneity. When it was converted to in situ combustion, the injection gas often break through along the high permeability layers in the fire drive wells that make the sweep area smaller and decrease the reservoir recovery. By analysis on the gas channeling of in situ combustion occurred in the heavy oil reservoirs, the methods was put forward to develop heavy oil reservoir using in situ combustion reasonably including well space infilling, controlling the gas injection rate, adding roam surfactant agent and using fire drive with horizontal well assisted etc. to prevent the condition of gas channeling occurring. It will greatly improve the success and adaptability of the in situ combustion used in vertical wells of the heavy oil reservoir by using these methods. It also will build on basis of the heavy oil reservoir converted to in situ combustion development.

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