New Method of Productivity Equation for Multibranch Horizontal Well in Three-Dimensional Anisotropic Oil Reservoirs

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Junlai Wu ◽  
Yuetian Liu ◽  
Haining Yang
Keyword(s):  
Oil Recovery ◽  
Horizontal Well ◽  
Three Dimensional ◽  
Branch Length ◽  
Production Method ◽  
Oil Reservoirs ◽  
Efficient Production ◽  
Branch Number ◽  
Single Well ◽  
Anisotropic Reservoirs

As a highly efficient production method, multibranch horizontal well is widely used in the development of low permeability reservoirs, naturally fracture reservoirs, heavy oil reservoirs, shallow layer reservoirs, and multilayer reservoirs, because it can significantly improve the productivity of a single well, inhibit edge or bottom water coning, and enhance oil recovery. This paper presents a new productivity equation for multibranch horizontal well in 3D anisotropic reservoirs. By applying coordinate transformation, a 3D anisotropic reservoir is transformed into an equivalent isotropic reservoir with considering wellbore deformation and vertical radial flow. An analytical solution of multibranch horizontal well productivity in 3D anisotropic reservoirs is obtained by using pseudo-3D solving method and similar flow replaces theory. The results show that branch number n, branch length (l), and permeability anisotropy degree (β3) are the three main factors that have big effects on the production rate of multibranch horizontal well.

A New High-Temperature Gel for Profile Control in Heavy Oil Reservoirs

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Changjiu Wang ◽  
Huiqing Liu ◽  
Qiang Zheng ◽  
Yongge Liu ◽  
Xiaohu Dong ◽  
...  
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Three Dimensional ◽  
Heat Stability ◽  
Steam Injection ◽  
Oil Reservoirs ◽  
Steam Flooding ◽  
Profile Control ◽  
Heavy Oil Reservoirs

Controlling the phenomenon of steam channeling is a major challenge in enhancing oil recovery of heavy oil reservoirs developed by steam injection, and the profile control with gel is an effective method to solve this problem. The use of conventional gel in water flooding reservoirs also has poor heat stability, so this paper proposes a new high-temperature gel (HTG) plugging agent on the basis of a laboratory experimental investigation. The HTG is prepared with nonionic filler and unsaturated amide monomer (AM) by graft polymerization and crosslinking, and the optimal gel formula, which has strong gelling strength and controllable gelation time, is obtained by the optimization of the concentration of main agent, AM/FT ratio, crosslinker, and initiator. To test the adaptability of the new HTG to heavy oil reservoirs and the performance of plugging steam channeling path and enhancing oil recovery, performance evaluation experiments and three-dimensional steam flooding and gel profile control experiments are conducted. The performance evaluation experiments indicate that the HTG has strong salt resistance and heat stability and still maintains strong gelling strength after 72 hrs at 200 °C. The singular sand-pack flooding experiments suggest that the HTG has good injectability, which can ensure the on-site construction safety. Moreover, the HTG has a high plugging pressure and washing out resistance to the high-temperature steam after gel forming and keeps the plugging ratio above 99.8% when the following steam injected volume reaches 10 PV after gel breakthrough. The three-dimensional steam flooding and gel profile control experiments results show that the HTG has good plugging performance in the steam channeling path and effectively controls its expanding. This forces the following steam, which is the steam injected after the gelling of HTG in the model, to flow through the steam unswept area, which improves the steam injection profile. During the gel profile control period, the cumulative oil production increases by 294.4 ml and the oil recovery is enhanced by 8.4%. Thus, this new HTG has a good effect in improving the steam injection profile and enhancing oil recovery and can be used to control the steam channeling in heavy oil reservoirs.

Single-Phase Inflow Performance Relationship for Horizontal, Pinnate-Branch Horizontal, and Radial-Branch Wells

SPE Journal ◽  
2012 ◽  
Vol 18 (02) ◽  
pp. 219-232 ◽  
Author(s):  
Huiqing Liu ◽  
Jing Wang ◽  
Jian Zheng ◽  
Ying Zhang
Keyword(s):  
Horizontal Well ◽  
Branch Length ◽  
Horizontal Wells ◽  
Finite Conductivity ◽  
Nonlinearity Coefficient ◽  
Oil Viscosity ◽  
Branch Number ◽  
Nonlinear Characteristics ◽  
Relative Roughness ◽  
Inflow Performance

Summary Horizontal and multibranch wells are likely to become the major means of modern exploitation strategies; inflow performances for these wells are needed. Because this paper considers the finite conductivity of a horizontal well, it establishes the inflow performance relationships (IPRs) for different branch configurations of horizontal wells. We find that the IPR of a horizontal well presents nonlinear characteristics and is similar to Vogel's equation, which has been used extensively and successfully for analyzing the IPR of a vertical well in a solution-gas-drive reservoir. Instead of the effect of a two-phase (oil and gas) flow in a reservoir described by Vogel's equation, the nonlinear characteristics of horizontal wells are mainly the result of pressure drops caused by friction, acceleration, and gravity along the horizontal wellbore. The nonlinearity coefficient presents the pressure drop along the major branch, and it is a function of major-wellbore length, major-wellbore diameter, oil viscosity, and relative roughness. Then, the horizontal-well IPR is used to study the performance of the pinnate-branch horizontal well and the radial-branch (horizontal lateral) well. The branch number, branch length, major-wellbore length, major-wellbore diameter, oil viscosity, and relative roughness are combined into grouped parameters to present the effect on the deliverability incremental ratio JH and the nonlinearity coefficient ratio Rv of the pinnate-branch horizontal well to the conventional horizontal well, which show regression relationships with the grouped parameters for pinnate-branch horizontal wells. In addition, another binomial relationship between the deliverability incremental ratio JV and the grouped parameter combined by branch number, branch length, and equivalent oil drainage diameter is obtained for radial-branch (horizontal lateral) wells. The new IPR also covers conventional horizontal wells and vertical wells (with no branch) because the deliverability incremental ratios JH and JV in both cases are unity. The IPR is very valuable for calculating the productivity of horizontal wells, pinnate-branch horizontal wells, and radial-branch wells.

A Novel Method to Enhance Oil Recovery by Inter-fracture Injection and Production through the Same Multi-fractured Horizontal Well

2021 ◽  
pp. 1-19
Author(s):  
Youwei He ◽  
Yu Qiao ◽  
Jiazheng Qin ◽  
Yong Tang ◽  
Yong Wang ◽  
...  
Keyword(s):  
Water Resources ◽  
Oil Recovery ◽  
Horizontal Well ◽  
Oil Production ◽  
Oil Reservoirs ◽  
Hydraulic Fractures ◽  
Discrete Fracture Model ◽  
Unconventional Oil ◽  
Fractured Horizontal Well ◽  
Enhance Oil Recovery

Abstract Conventional enhanced oil recovery (EOR) approaches are inefficient in the unconventional reservoirs. This paper provides a novel approach to enhance oil recovery from unconventional oil reservoirs through synchronous inter-fracture injection and production (SiFIP) and asynchronous inter-fracture injection and production (AiFIP). The compartmental embedded discrete fracture model (cEDFM) is introduced to simulate complex fracture geometries to quantitatively evaluate the performance of SiFIP and AiFIP. EOR performances using multiple producing methods are investigated (i.e., depletion, fluid flood, fluid Huff and Puff, SiFIP, AiFIP. Higher cumulative oil production rates can be achieved by AiFIP and SiFIP. AiFIP yields the highest oil recovery factor, two times higher than depletion. Compared with SiFIP, AiFIP may be a preferred method when CO2/water resources are short. The impacts of fracture and injection parameters on oil production are discussed. The feasible well completions for AiFIP and SiFIP are provided. AiFIP (CO2) achieves the best EOR performance among different producing methods. This paper demonstrates the feasibility of SiFIP and AiFIP to improve oil recovery. The proposed methods improve flooding performance by transforming fluid injection among wells to among hydraulic fractures from the same Multi-fractured horizontal well (MFHW), which is a promising EOR approach in unconventional oil reservoirs. The proposed EOR method (AiFIP-CO2) can improve the oil recovery, and mitigate the emission of CO2 as well as reduce the waste of water resources.

scholarly journals Under pressure: Hydrogel swelling in a granular medium

2021 ◽  
Vol 7 (7) ◽  
pp. eabd2711
Author(s):  
Jean-François Louf ◽  
Nancy B. Lu ◽  
Margaret G. O’Connell ◽  
H. Jeremy Cho ◽  
Sujit S. Datta
Keyword(s):  
Oil Recovery ◽  
Granular Medium ◽  
Granular Media ◽  
Three Dimensional ◽  
Osmotic Swelling ◽  
Widespread Adoption ◽  
Dry Soil ◽  
Hydrogel Swelling

Hydrogels hold promise in agriculture as reservoirs of water in dry soil, potentially alleviating the burden of irrigation. However, confinement in soil can markedly reduce the ability of hydrogels to absorb water and swell, limiting their widespread adoption. Unfortunately, the underlying reason remains unknown. By directly visualizing the swelling of hydrogels confined in three-dimensional granular media, we demonstrate that the extent of hydrogel swelling is determined by the competition between the force exerted by the hydrogel due to osmotic swelling and the confining force transmitted by the surrounding grains. Furthermore, the medium can itself be restructured by hydrogel swelling, as set by the balance between the osmotic swelling force, the confining force, and intergrain friction. Together, our results provide quantitative principles to predict how hydrogels behave in confinement, potentially improving their use in agriculture as well as informing other applications such as oil recovery, construction, mechanobiology, and filtration.

scholarly journals UV Nanoimprint Lithography: Geometrical Impact on Filling Properties of Nanoscale Patterns

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 822
Author(s):  
Christine Thanner ◽  
Martin Eibelhuber
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Nanoimprint Lithography ◽  
Failure Modes ◽  
Production Method ◽  
Efficient Production ◽  
Comprehensive Overview ◽  
Replication Method ◽  
Wide Range ◽  
Pattern Size

Ultraviolet (UV) Nanoimprint Lithography (NIL) is a replication method that is well known for its capability to address a wide range of pattern sizes and shapes. It has proven to be an efficient production method for patterning resist layers with features ranging from a few hundred micrometers and down to the nanometer range. Best results can be achieved if the fundamental behavior of the imprint resist and the pattern filling are considered by the equipment and process parameters. In particular, the material properties and pattern size and shape play a crucial role. For capillary force-driven filling behavior it is important to understand the influencing parameters and respective failure modes in order to optimize the processes for reliable full wafer manufacturing. In this work, the nanoimprint results obtained for different pattern geometries are compared with respect to pattern quality and residual layer thickness: The comprehensive overview of the relevant process parameters is helpful for setting up NIL processes for different nanostructures with minimum layer thickness.

The Mechanism of Flue Gas Injection for Enhanced Light Oil Recovery

2004 ◽  
Vol 126 (2) ◽  
pp. 119-124 ◽  
Author(s):  
O. S. Shokoya ◽  
S. A. (Raj) Mehta ◽  
R. G. Moore ◽  
B. B. Maini ◽  
M. Pooladi-Darvish ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Flue Gas ◽  
Gas Injection ◽  
Cost Effective ◽  
Air Injection ◽  
Oil Reservoirs ◽  
Flue Gases ◽  
Low Permeability ◽  
Light Oil ◽  
Light Oil Reservoirs

Flue gas injection into light oil reservoirs could be a cost-effective gas displacement method for enhanced oil recovery, especially in low porosity and low permeability reservoirs. The flue gas could be generated in situ as obtained from the spontaneous ignition of oil when air is injected into a high temperature reservoir, or injected directly into the reservoir from some surface source. When operating at high pressures commonly found in deep light oil reservoirs, the flue gas may become miscible or near–miscible with the reservoir oil, thereby displacing it more efficiently than an immiscible gas flood. Some successful high pressure air injection (HPAI) projects have been reported in low permeability and low porosity light oil reservoirs. Spontaneous oil ignition was reported in some of these projects, at least from laboratory experiments; however, the mechanism by which the generated flue gas displaces the oil has not been discussed in clear terms in the literature. An experimental investigation was carried out to study the mechanism by which flue gases displace light oil at a reservoir temperature of 116°C and typical reservoir pressures ranging from 27.63 MPa to 46.06 MPa. The results showed that the flue gases displaced the oil in a forward contacting process resembling a combined vaporizing and condensing multi-contact gas drive mechanism. The flue gases also became near-miscible with the oil at elevated pressures, an indication that high pressure flue gas (or air) injection is a cost-effective process for enhanced recovery of light oils, compared to rich gas or water injection, with the potential of sequestering carbon dioxide, a greenhouse gas.

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