Performance of Hydraulically Fractured Wells in Xinjiang Oilfield: Experimental and Simulation Investigations on Laumontite-Rich Tight Glutenite Formation

PetroChina’s Xinjiang oilfield has a large quantity of tight oil reserves and hydraulic fracturing technology has been widely used to achieve commercial production. Some parts of this tight glutenite formation are laumontite-rich and the actual productivity of the hydraulically fractured wells is less than expected. To figure out the ways that laumontite affects tight glutenite well productivity, comprehensive experimental and numerical simulation studies have been conducted to investigate the rock mechanical properties, fluid flow behaviors and the major controlling factor of productivity. Laboratory results indicate that the tight glutenite formation with higher laumontite content has higher initial porosity, permeability but lower yield strength and more severe stress sensitivity in both permeability and fracture conductivity. For laumontite-rich glutenite rocks, there are commonly three types of rock deformation during the loading process: elastic compression, shear dilation and shear enhanced compaction. Both elastic compression and shear enhanced compaction will cause the reduction on rock porosity and permeability. A fully coupled finite element model (FEM) considering stress-induced permeability evolution was introduced to simulate the production process. Permeability evolution models of three different deformation stages were presented, respectively. Simulation results showed that our model is in good agreements with the well testing data. The simulated oil production characteristics for permeability evolution coupled and uncoupled models were discussed. Results showed the strong stress-induced permeability reduction is the major factor that laumontite causing the low and quickly declining oil rates. Initial permeability has a positive effect on productivity and stress-induced fracture conductivity reduction has slight influence on productivity. The results of this paper indicate that the stress-induced permeability evolution in the oil production process must be considered to accurately evaluating reservoirs in the studied area.

Download Full-text

A Model of Reservoir Permeability Evolution during Oil Production

Energies ◽

10.3390/en14092695 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2695

Author(s):

Evgenii Kozhevnikov ◽

Evgenii Riabokon ◽

Mikhail Turbakov

Keyword(s):

Mathematical Model ◽

Oil And Gas ◽

Flow Characteristics ◽

Oil Production ◽

Initial Permeability ◽

Well Testing ◽

Reservoir Pressure ◽

Effective Pressure ◽

Permeability Evolution ◽

Reservoir Properties

In this paper, we present a mathematical model to predict the evolution of rock permeability depending on effective pressure during oil production. The model is based on the use of the results of well testing data from wells operating in the oil fields of the Perm–Solikamsk region in the north of the Volgo Ural oil and gas province. Dependences of the change in flow characteristics in the reservoir on the effective pressure were established. We performed a comparative assessment using permeability and effective pressure data that were normalized to dimensionless forms of k/ko and P/Po. The factors and their influence on the nature of the change in permeability from the reservoir pressure were determined. Depending on the type of rock, its composition, initial permeability, and bedding conditions, we determined the limits of variation of the constants in empirical equations describing the change in the permeability of rocks from the effective pressure. The mathematical model we developed enables the prediction of the change in permeability of rocks during oil production from reservoirs on the basis of reservoir properties such as initial permeability, initial reservoir pressure, average bedding depth, net-to-gross ratio, and initial effective rock pressure.

Download Full-text

Unlocking Idle Production in an Offshore Sandstone Oil Field With Gas Hydrate Issues

10.2118/200904-ms ◽

2021 ◽

Author(s):

Babalola Daramola

Keyword(s):

Gas Hydrate ◽

Oil Production ◽

Oil Field ◽

Third Party ◽

Flow Assurance ◽

Well Testing ◽

Production Wells ◽

Oil Flow ◽

Offshore Oil ◽

Production Losses

Abstract This publication presents how an oil asset unlocked idle production after numerous production upsets and a gas hydrate blockage. It also uses economics to justify facilities enhancement projects for flow assurance. Field F is an offshore oil field with eight subsea wells tied back to a third party FPSO vessel. Field F was shut down for turnaround maintenance in 2015. After the field was brought back online, one of the production wells (F5) failed to flow. An evaluation of the reservoir, well, and facilities data suggested that there was a gas hydrate blockage in the subsea pipeline between the well head and the FPSO vessel. A subsea intervention vessel was then hired to execute a pipeline clean-out operation, which removed the gas hydrate, and restored F5 well oil production. To minimise oil production losses due to flow assurance issues, the asset team evaluated the viability of installing a test pipeline and a second methanol umbilical as facilities enhancement projects. The pipeline clean-out operation delivered 5400 barrels of oil per day production to the asset. The feasibility study suggested that installing a second methanol umbilical and a test pipeline are economically attractive. It is recommended that the new methanol umbilical is installed to guarantee oil flow from F5 and future infill production wells. The test pipeline can be used to clean up new wells, to induce low pressure wells, and for well testing, well sampling, water salinity evaluation, tracer evaluation, and production optimisation. This paper presents production upset diagnosis and remediation steps actioned in a producing oil field, and aids the justification of methanol umbilical capacity upgrade and test pipeline installations as facilities enhancement projects. It also indicates that gas hydrate blockage can be prevented by providing adequate methanol umbilical capacity for timely dosing of oil production wells.

Download Full-text

Parameters Optimization of Fractures with One for Injection and Two Others for Production of Horizontal Wells Fracturing on Offshore Oilfields

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.489 ◽

2014 ◽

Vol 962-965 ◽

pp. 489-493

Author(s):

Zhi Qiang Li ◽

Yong Quan Hu ◽

Wen Jiang Xu ◽

Jin Zhou Zhao ◽

Jian Zhong Liu ◽

...

Keyword(s):

Horizontal Well ◽

Oil Production ◽

Horizontal Wells ◽

Simulation Method ◽

Parameters Optimization ◽

Development Mode ◽

Fracture Conductivity ◽

Fracture Length ◽

Fractured Horizontal Well ◽

Production Research

This article presents a new exploitation method based on the same fractured horizontal well with fractures for injection or production on offshore low permeability oilfields for the purpose of adapting to their practical situations and characteristics, which means fractures close to the toe of horizontal well used for injecting water and fractures near the heel of horizontal well used for producing oil. According to proposed development mode of fracturing, relevant physical model is established, Then reservoir numerical simulation method has been applied to study the effect of arrangement pattern of injection and production fractures, fracture conductivity, fracture length on oil production. Research indicates cumulative oil production is much higher by employing the middle fracture for injecting water compared with using the remote one, suggesting that the middle fracture adopted for injecting water, and hydraulic fracture length and conductivity have been optimized. The proposed development pattern of a staged fracturing for horizontal wells with some fractures applied for injecting water and others for production based on the same horizontal well provides new thoughts for offshore oilfields exploitation.

Download Full-text

A Comprehensive Model Integrating the Stress Sensitivity for Pressure Transient Behavior Study on the Two-Zone System for Offshore Loose Sandstone Reservoirs

10.2118/204793-ms ◽

2021 ◽

Author(s):

Chong Cao ◽

Linsong Cheng ◽

Xiangyang Zhang ◽

Pin Jia ◽

Wenpei Lu

Keyword(s):

Flow Regimes ◽

Transient Behavior ◽

Stress Sensitivity ◽

Composite Model ◽

Zone Model ◽

Well Testing ◽

Comprehensive Model ◽

Pressure Transient ◽

Sandstone Reservoirs ◽

Sandstone Formation

Abstract Permeability changes in the weakly consolidated sandstone formation, caused by sand migration, has a serious impact on the interpretation of well testing and production prediction. In this article, a two-zone comprehensive model is presented to describe the changes in permeability by integrating the produced sand, stress sensitivity characteristics. In this model, inner zone is modeled as a higher permeability radial reservoir because of the sand migration, while the outer zone is considered as a lower permeability reservoir. Besides, non-Newtonian fluid flow characteristics are considered as threshold pressure gradient in this paper. As a result, this bi-zone comprehensive model is built. The analytical solution to this composite model can be obtained using Laplace transformation, orthogonal transformation, and then the bottomhole pressure in real space can be solved by Stehfest and perturbation inversion techniques. Based on the oilfield cases validated in the oilfield data from the produced sand horizontal well, the flow regimes analysis shows seven flow regimes can be divided in this bi-zone model considering stress sensitive. In addition, the proposed new model is validated by the compassion results of traditional method without the complex factors. Besides, the effect related parameters of stress sensitivity coefficient, skin factor, permeability ratio and sanding radius on the typical curves of well-testing are analyzed. This work introduces two-zone composite model to reflect the variations of permeability caused by the produced sand in the unconsolidated sandstone formation, which can produce great influence on pressure transient behavior. Besides, this paper can also provide a more accurate reference for reservoir engineers in well test interpretation of loose sandstone reservoirs.

Download Full-text

Evaluating the filtration property of fracturing fluid and fracture conductivity of coalbed methane wells considering the stress-sensitivity effects

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2020.103379 ◽

2020 ◽

Vol 80 ◽

pp. 103379

Author(s):

Ya Meng ◽

Zhiping Li ◽

Fengpeng Lai

Keyword(s):

Coalbed Methane ◽

Stress Sensitivity ◽

Filtration Property ◽

Fracturing Fluid ◽

Fracture Conductivity

Download Full-text

A Model to Manage Crude Palm Oil Production System

MATEC Web of Conferences ◽

10.1051/matecconf/201925502001 ◽

2019 ◽

Vol 255 ◽

pp. 02001 ◽

Cited By ~ 1

Author(s):

Inyang John ◽

Andrew-Munot Magdalene ◽

Syed Shazali Syed Tarmizi ◽

Johnathan Tanjong Shirley

Keyword(s):

Simulation Model ◽

Production Process ◽

Conceptual Model ◽

Palm Oil ◽

Production System ◽

Oil Production ◽

Future Research ◽

Crude Palm Oil ◽

Model Based ◽

The Future

This paper reviews key production process for crude palm oil and highlights factors that highly influence the production of crude palm oil. This paper proposes a generic conceptual model for crude palm production process considering these factors. The conceptual model could be modified to consider other factors not included in this paper. The future research would be to construct a simulation model based on the conceptual model proposed in this paper and analyse the effect of these factors on the performance of crude palm oil production system.

Download Full-text

Oil production process optimization resultant from intelligent field technologies implementation in Samotlorskoe field (Russian)

10.2118/161978-ru ◽

2012 ◽

Author(s):

Sergey Shevchenko ◽

V. A. Navozov ◽

D. V. Mironov ◽

R. L. Pchelnikov ◽

E. Ya. Muslimov

Keyword(s):

Production Process ◽

Process Optimization ◽

Oil Production

Download Full-text

Technoeconomic Assessment of a Fast Pyrolysis Bio-oil Production Process Integrated to a Fluidized Bed Boiler

Energy & Fuels ◽

10.1021/acs.energyfuels.5b01329 ◽

2015 ◽

Vol 29 (9) ◽

pp. 5885-5893 ◽

Cited By ~ 7

Author(s):

Kristin Onarheim ◽

Jani Lehto ◽

Yrjö Solantausta

Keyword(s):

Production Process ◽

Fluidized Bed ◽

Fast Pyrolysis ◽

Oil Production ◽

Bio Oil

Download Full-text

A New Method of Fracture Designing to Elevate SRV in Natural Fractured Sandstone Reservoir

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.1471 ◽

2013 ◽

Vol 275-277 ◽

pp. 1471-1475 ◽

Cited By ~ 1

Author(s):

Ding Wei Weng ◽

Qun Lei ◽

Zi Yi Guo ◽

Yong Luo

Keyword(s):

Oil Production ◽

New Method ◽

Natural Fractures ◽

Fracture Conductivity ◽

Fracture Length ◽

Reservoir Volume ◽

Net Pressure ◽

Sandstone Reservoir ◽

Fractured Sandstone ◽

The Relationship

This paper firstly analyze the relationship between the fracture net pressure and the sand to fluid ratio (SOR), and the conclusion is that the high SOR could accumulate high net pressure to make the natural fractures open in natural fractured sandstone reservoir. Then relationship between the cumulative oil production and opening the natural fractures is analyzed by means of reservoir numerical simulation, and the conclusion is that the cumulative oil production increased apparently as the area of opening natural fractures increasing. Based on the analyses, a new method of optimizing fracture conductivity to elevate the stimulating reservoir volume (SRV) was formed: firstly, evaluate the stress field and calculate the critical net pressure of the natural fractures opening; secondly, determine the average proppant concentration according the relationship between the net pressure and proppant concentration; thirdly, calculate the fracture conductivity according to the proppant concentration; at last, optimize the fracture length. There are two key works: one is acquiring the accurate principal stress combining the indoor experiment and field test; the other one is acquiring accurate conductivity of proppant, and long term conductivity experiments are recommended.

Download Full-text