Characteristics and Controlling Factors of Tight Marl Reservoirs with an Eyelid-Shaped Structure of the First Member of the Deep Maokou Formation in Eastern Sichuan

Jiang, Qingchun; Wang, Weiming; Lyu, Qixia

doi:10.3390/en16052353

Cited by 2 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Sichuan Basin marl tight oil reservoirs are characterized by strong heterogeneity, low porosity, and low permeability [36]. The lithology is mainly argillaceous limestone and limestone, and the argillaceous limestone and limestone appear alternately [37].…”

Section: Optimization Of Fracturing Parameters In Tight Marl Reservoirmentioning

confidence: 99%

A New Fracturing Method to Improve Stimulation Effect of Marl Tight Oil Reservoir in Sichuan Basin

Wang,

Fan,

et al. 2023

Processes

View full text Add to dashboard Cite

China’s argillaceous limestone reservoir has a lot of oil and gas resources, and hydraulic fracturing of the argillaceous limestone reservoir faces many difficulties. The first problem is that the heterogeneity of the argillaceous limestone reservoir is strong, and it is difficult to optimize fracturing parameters. The second problem is that there are a lot of natural fractures in the argillaceous limestone reservoir, which leads to a lot of fracturing fluid loss. The third problem is that the closure pressure of the argillaceous limestone reservoir is high, and the conductivity of fractures decreases rapidly under high closure pressure. The last problem is that the fracture shape of the argillaceous limestone reservoir is complex, and the law of proppant migration is unclear. The main research methods in this paper include reservoir numerical simulation, fluid-loss-reducer performance evaluation, flow conductivity tests and proppant migration visualization. To solve the above problems, this paper establishes the fracturing productivity prediction model of complex lithology reservoirs and defines the optimal hydraulic fracturing parameters of the argillous limestone reservoir in the Sichuan Basin. The 70/140 mesh ceramide was selected as the fluid loss additive after an evaluation of the sealing properties of different mesh ceramides. At the same time, the hydraulic fracture conductivity test is carried out in this paper, and it is confirmed that the fracture conductivity of 70/140 mesh and 40/70 mesh composite particle-size ceramics mixed according to the mass ratio of 5:5 is the highest. When the closure pressure is 40 MPa, the conductivity of a mixture of 70/140 mesh ceramic and 40/70 mesh ceramic is 35.6% higher than that of a mixture of 70/140 mesh ceramic and 30/50 mesh ceramic. The proppant migration visualization device is used to evaluate the morphology of the sand dike formed by the ceramsite, and it is clear that the shape of the sand dike is the best when the mass ratio of 70/140 mesh ceramsite and 40/70 mesh ceramsite is 6:4. The research results achieved a good stimulation effect in the SC1 well. The daily oil production of the SC1 well is 20 t, and the monitoring results of the wide-area electromagnetic method show that the fracturing fracture length of the SC1 well is up to 129 m.

show abstract

Section: Optimization Of Fracturing Parameters In Tight Marl Reservoirmentioning

confidence: 99%

A New Fracturing Method to Improve Stimulation Effect of Marl Tight Oil Reservoir in Sichuan Basin

Wang,

Fan,

et al. 2023

Processes

View full text Add to dashboard Cite

show abstract

Evaluation of the current in situ stress in the middle Permian Maokou Formation in the Longnüsi area of the central Sichuan Basin, China

Zhao,

Qin,

et al. 2023

Open Geosciences

View full text Add to dashboard Cite

The middle Permian Maokou Formation in the Longnüsi area in the central Sichuan Basin is currently a key formation for exploration and development. The evaluation of the current in situ stress in this area is of great significance for fracture prediction, well pattern deployment, drilling and construction, and fracturing stimulation. This study clarifies the current direction and magnitude distributions of the in situ stress by evaluating the Maokou Formation in the Longnüsi area using finite-element numerical simulation, acoustic emission experiments, and logging data (including data from imaging logging, array acoustic logging, conventional logging, and cross-dipole acoustic logging). Specifically, the current maximum horizontal stress of the Maokou Formation in the Longnüsi area is mainly in the NW‒SE direction, and the stress direction is greatly affected by the local fault zone. The current minimum horizontal stress magnitude of the Maokou Formation obtained by acoustic emission experiments is between 96.29 and 114.36 MPa, the current maximum horizontal stress magnitude is between 126.01 and 145.10 MPa, and the current horizontal stress difference is between 25.59 and 32.58 MPa. The current minimum and maximum horizontal stress magnitudes both decrease from north to south. The current horizontal stress parameters calculated by Huang’s model are not significantly different from those experimentally measured: there is a difference of less than 8% in the current minimum horizontal stress magnitude, a difference of less than 9% in the maximum horizontal stress magnitude, and a difference of less than 15% in the current horizontal stress difference. Therefore, Huang’s model has good applicability in terms of calculating the current horizontal stresses in the Longnüsi area. The current horizontal stress parameters, which are numerically simulated with the finite-element method, are also not much different from those experimentally measured: there is a difference of less than 11% in the current minimum horizontal stress magnitude, a difference of less than 10% in the maximum horizontal stress magnitude, and a difference of less than 20% in the current horizontal stress difference. The numerically simulated current horizontal stress also decreases from north to south. Therefore, the simulated results are highly accurate. This study clarifies the directions and magnitudes of the current in situ stress state of the Maokou Formation in the Longnüsi area of the central Sichuan Basin and provides a basis for the formulation of exploration and development plans for the Maokou Formation reservoir in the study area.

show abstract

Characteristics and Controlling Factors of Tight Marl Reservoirs with an Eyelid-Shaped Structure of the First Member of the Deep Maokou Formation in Eastern Sichuan

Cited by 2 publications

References 8 publications

A New Fracturing Method to Improve Stimulation Effect of Marl Tight Oil Reservoir in Sichuan Basin

A New Fracturing Method to Improve Stimulation Effect of Marl Tight Oil Reservoir in Sichuan Basin

Evaluation of the current in situ stress in the middle Permian Maokou Formation in the Longnüsi area of the central Sichuan Basin, China

Contact Info

Product

Resources

About