Session: 11-10-03 Development of Unconventional Reservoirs-3

Paper Number: 78776

78776 - Small Sizes of Molybdenum Disulfide Nanosheets As Heavy Oil Viscosity Reducers 

Abstract:

Objectives/Scope:

The world is very rich in heavy oil resources, accounting for more than 70% of the total global oil resources (UNITAR). The high content of asphaltenes and colloids in heavy oil lead to their high viscosity, which is difficult to exploit and transport. Nanomaterials have become an important research area in reducing viscosity of crude oil. The commonly used nano-materials are mainly oil-soluble materials, and its using dosage is relatively large. In this work, a series of amphiphilic molybdenum dioxide (MoS₂) nanosheets are developed, and they can reduce the viscosity of crude oil by an ultralow concentration aqueous solution.

Methods, Procedures, Process:

Firstly, nanosheets were synthesized by the hydrothermal methods. The influence factors such as raw material ratio, temperature and time were investigated. Then, SEM and TEM are used to systemically characterize the morphology and structure of MoS₂ nanosheets. Then, the properties of MoS2 nanosheets are tested, including those of the nanosheets sizes, viscosity reduction and interfacial activity. The relationship between these properties s and viscosity reduction abilities were studied. Finally, based on viscosity reduction testing results, optimal MoS₂ nanosheets formulation and dosage are determined.

Results, Observations, Conclusions:

By controlling the stirring and temperature, MoS₂ nanosheets with sizes from 30nm to 160nm were synthesized, respectively. Modifying them with oleyl amine, the amphiphilic nanosheets can be obtained. SEM and TEM show that they are materials with layered nano-structure and commonly composed of 5-6 layers. These nanosheets have good interfacial activity, wetting and emulsifying ability. By adding 100 PPM of MoS₂ nanosheets to the mixture of heavy oil and water, the viscosity of these system can fell from >100 mPa·s to 1.8 mPa·s. The smaller the size of the MoS₂ nanosheets, the better their viscosity reduction ability. Minimum using dosage of these nanosheets is 20-30 PPM, and the optimal size is 50nm.

Novel/Additive Information:

Many researchers have studied the effect of spherical nanoparticles as viscosity reducers in the heavy oil reservoirs. However, there is a lack of research on two-dimensional material for dropping viscosity. In addtion, it is proposed that nanosheets has a similar structure with asphaltenes. It can enter layers of the asphaltenes and break up their aggregates. We predicted that nanosheets will gradually become a new field for the development of heavy oil, especially tight heavy oil.

Presenting Author: Er-Dong Yao China University of Petroleum China

Authors:

Guodong Wu Engineering Technology Research Institute of PetroChina Xinjiang Oilfield Company
Yanchi Liu China University of Petroleum Beijing, Unconventional Petroleum Research Institute
Maieryemuguli Anwaier Engineering Technology Research Institute of PetroChina Xinjiang Oilfield Company
Er-Dong Yao China University of Petroleum China
Hongda Ren Engineering Technology Research Institute of PetroChina Xinjiang Oilfield Company
Yuan Li China University of Petroleum Beijing, Unconventional Petroleum Research Institute