The Study on 3D Geomechanical Modeling Improves Horizontal Well Drilling Performance in Tight Oil Reservoir

Author(s):  
Yong Wang ◽  
Haijun Luan ◽  
Chuanyi Tang ◽  
Dong Zhao ◽  
Wei Zhou ◽  
...  
2021 ◽  
Author(s):  
Jingfeng Yu ◽  
Diao Zhou ◽  
Bo Zhang ◽  
Haiping Meng ◽  
Tong Li ◽  
...  

Abstract MH oilfield is a fan delta deposited unconventional tight oil reservoir with complex lithology of volcanic rocks, metamorphic rocks, conglomerate, and claystone. The drilling efficiency was optimized by using the first-generation boundary mapping technology with Rotary Steering System (RSS) during the first batch drilling campaign (H2-2016∼H1-2017), which was mentioned in IADC/SPE-190998-MS. But with the development going further, more and more wells drilled into shale interbed causing low pay zone exposure, long drilling duration, and numerous drilling hazards. The overall drilling performance was not optimistic as before, the average Rate Of Penetration (ROP) decreased by 30.7% and the average footage per run decreased by 38.9% during horizontal section operation in some specific blocks of MH oilfield. By reviewing the detailed drilling and geology material of the first batch drilling, the challenges were defined. There is lateral irregular thin shale interbed existing in this conglomeratic reservoir which is rarely observed from the nearby wells in the first batch drilling zone. That unstable shale interbed with 0.5-2m thickness isolated the target into 2 to 3 components. The first-generation boundary mapping technology can only detect the nearest up or down boundary, with this limitation, it is difficult to reveal these laterally unstable shale interbed. It is crucial to precisely delineate the irregular thin interbed to develop this complex reservoir. Meanwhile, the bit selection which didn't catch up with the formation change is another issue that needs to be optimized timely. To solve the above challenges, the new generation boundary mapping while drilling technology was introduced to this project, it has 3 or more boundaries detecting ability at the same time, which can delineate the irregular thin interbed and optimize real-time Well Placement decision making. Meanwhile, the bit design and selection based on the timely geological data interpretation helped to improve drilling efficiency. This innovative integrated method deployed in phase II horizontal well drilling campaign proved to be an effective approach to optimize geosteering and drilling performance. The clear reservoir geometry delineation effectively helps avoid entering the irregular shale interbed in real-time, thus improve the pay zone exposure and trajectory smoothness. Till 2018, more than 50 wells were completed, the overall drilling performance of 2018 has been improved by 47.2% of footage per run and 42.2% of ROP compared with statistical results of H2-2017 of the M131 block and nearly back to the normal level. In this paper, the authors will demonstrate how this integrated approach helps optimize Well Placement, enhance drilling efficiency and save budget with some exemplary case studies. With this success, the authors believe this approach and techniques could effectively address the following horizontal well drilling campaign in this unconventional tight oil reservoir.


2019 ◽  
Vol 7 (5) ◽  
pp. 1485-1503 ◽  
Author(s):  
Yu‐long Zhao ◽  
Ling‐fu Liu ◽  
Lie-hui Zhang ◽  
Xu‐Yang Zhang ◽  
Bo Li

2014 ◽  
Vol 1073-1076 ◽  
pp. 2286-2291
Author(s):  
Fang Fang Wu ◽  
Jin Chuan Zhang ◽  
Hao Zhang ◽  
Jin Long Wu

Jimusaer tight oil reservoir is characterized by complex lithology, low permeability and high total organic carbon (TOC) content. These features make conventional logging responses very complicated and bring big troubles to reservoir identification. Horizontal well drilling is extremely difficult due to high heterogeneity and uncertain faulting. To maximize oil production with low cost, an integrated solution is provided. First, accurate reservoir characteristics of the pilot well was got using an unconventional evaluation approach by combining capture spectroscopy log, micro-resistivity imager log, nuclear magnetic resonance log, et al. Second, structure analysis for sidetracking well and well correlation between the sidetracking well and the pilot well were done to guide the horizontal section drilling. Third, reservoir quality and completion quality were evaluated for horizontal well, and a 3D structural model was built to optimize the stimulation design by combining reservoir quality, completion quality and natural fractures.


2017 ◽  
Author(s):  
Qihong Feng ◽  
Kaiwen Dou ◽  
Xianmin Zhang ◽  
Xiangdong Xing ◽  
Tian Xia

2014 ◽  
Author(s):  
H.. Wang ◽  
X.. Liao ◽  
X.. Zhao ◽  
H.. Ye ◽  
X.. Dou ◽  
...  

Abstract As one kind of unconventional reservoirs, tight oil reservoir has become one of the main forces of oil reserves and production growth. The characteristics of tight oil reservoir are low porosity and ultra-low permeability, thus stimulated reservoir volume (SRV) should be conducted whether applying the mode of vertical wells or horizontal wells production. Tight oil reservoir is mostly developed by natural depletion or water flooding recently, but the problems are existed, including low recovery factor with natural depletion and the difficulty of water injection. To further improve the development effect of tight oil reservoir, CO2 flooding is proposed. Based on chang-8 tight oil reservoir in Ordos Basin, an oil sample of typical block is selected. The PVT experiments are conducted. The compositional numerical model of five-spot pattern is established with a horizontal well in the middle and 4 vertical wells on the edge. Based on the model, several CO2 flooding scenarios of horizontal well with different completion measures are studied. Furthermore, parameters such as the formation pressure, production rate, shut-in gas-oil ratio and total gas injection volume are optimized. The results of this study show that the recovery factor of horizontal well with SRV is higher than those of horizontal well and conventional fractured horizontal well. The minimum miscible pressure (MMP) and the total gas injection volume are two key factors of CO2 flooding effect. CO2 flooding of volume fractured horizontal well in tight oil reservoir can not only improve oil recovery, but also realize CO2 geological sequestration. It plays dual benefits of economy and environment. The study gives new ideas of CO2 flooding with volume fractured horizontal well for the Ordos Basin tight oil reservoir. It can be helpful for rapid and effective development of tight oil reservoirs in Ordos Basin.


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