Seismic sedimentology, facies analyses, and high-quality reservoir predictions in fan deltas: A case study of the Triassic Baikouquan Formation on the western slope of the Mahu Sag in China's Junggar Basin

Wu, Wei; Li, Quan; Pei, Jiaxue; Ning, Shuyuan; Liqing, Tong; Liu, Weiqing; Feng, Zhendong

doi:10.1016/j.marpetgeo.2020.104546

Cited by 29 publications

(13 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…17 , 18 Over the past few years, the Mahu oilfield in Junggar Basin has been discovered as an extremely large tight conglomerate oil field, which is guided by the accumulation model of a large shallow water retrogradation fan delta in the depression area. 19 − 21 Typically, marine tight oil or shale oil is characterized by stable deposition, simple structure, moderate burial depth, and high oil saturation. Moreover, the Mahu tight conglomerate oil reservoir belongs to the fluvial facies fan delta sedimentary system with near-source and rapid accumulation.…”

Section: Introductionmentioning

confidence: 99%

“…Exploration and development of tight oil and gas resources show a broad prospect. These resources are currently a new hotspot in global unconventional oil and gas development after shale gas. − As relevant technologies (e.g., volumetric fracturing and long horizontal well) have been advancing, tight oil and gas resources are expected to be a vital alternative of oil and gas to supply China’s high dependence on crude oil and ensure national energy security. − Global energy consumption is a vital input to many analyses of economic, energy, and environmental policies. , Over the past few years, the Mahu oilfield in Junggar Basin has been discovered as an extremely large tight conglomerate oil field, which is guided by the accumulation model of a large shallow water retrogradation fan delta in the depression area. − Typically, marine tight oil or shale oil is characterized by stable deposition, simple structure, moderate burial depth, and high oil saturation. Moreover, the Mahu tight conglomerate oil reservoir belongs to the fluvial facies fan delta sedimentary system with near-source and rapid accumulation. , The reservoir has a low effective production rate as a result of the overall complex lithology, poor physical properties, fast lateral variation of the reservoir, low oil saturation, lack of natural fracture development, and significant horizontal stress difference.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Factors of Productivity of Tight Conglomerate Reservoirs Based on Random Forest Algorithm

Wang

Jiang

et al. 2022

ACS Omega

View full text Add to dashboard Cite

The tight conglomerate reservoir of Baikouquan formation in the MA 131 well block in the Junggar basin abounds with petroleum reserves, yet the vertical wells in this reservoir have achieved a limited development effect. The tight conglomerate reservoirs have become an important target for exploration and exploitation. The high-efficiency development scheme of a small well spacing three-dimensional (3D) staggered well pattern has been determined by a series of field tests on well pattern and well spacing development. Multistage fracturing with a horizontal well has been demonstrated as the primary development technology. The horizontal wells in the MA 131 small well spacing demonstration area have achieved significantly different development effects, and the major controlling factors for high and stable production of a single well remain unclear. In this study, we proposed an evaluation model of major productivity controlling factors of the tight conglomerate reservoir to provide a reference for oil recovery based on a random forest (RF) machine-learning algorithm. The productivity factors were investigated from two aspects: petrophysical facies that are capable of indicating the genetic mechanism of geological dessert and engineering dessert parameters forming complex fracture networks. Resultantly, the reservoir in the MA 131 well block can be classified into 12 petrophysical facies according to the sedimentary characteristics and diagenesis analysis. The mercury injection curves of a variety of petrophysical facies can be classified into four reservoir quality types. The RF model was trained on 80% of the data to predict the oil well class using the selected features as primary inputs while the remaining 20% of the data were set to test the model performance. The results indicated that the RF model produced excellent results with only 12 misclassifications across the entire data set of 627 samples that represent <2% error. The important evaluation score of the random forest algorithm model showed that the reservoir type, oil saturation, horizontal stress difference, and gravel content are the most important four indicators, with each value exceeding 15%. Brittleness and maximum horizontal stress are considered the least important indexes, with values of less than 5%. Reservoir quality and oil saturation were confirmed as the major controlling factors and material foundation for oil wells’ high and stable production. As indicated in this study, stress difference and gravel content are the major controlling factors in the formation of a complex fracture network.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of Factors of Productivity of Tight Conglomerate Reservoirs Based on Random Forest Algorithm

Wang

Jiang

et al. 2022

ACS Omega

View full text Add to dashboard Cite

show abstract

“…Previous studies of delta front reservoirs focused mainly on outcrops [18,19] and modern analogs [20,21]. Characterizing the subsurface deltaic reservoir architecture is challenging owing to the complex sedimentary process and sandstone distribution intercut into this system [22,23].…”

Section: Introductionmentioning

confidence: 99%

Sedimentary Architecture Analysis of Deltaic Sand Bodies Using Sequence Stratigraphy and Seismic Sedimentology: A Case Study of Jurassic Deposits in Zhetybay Oilfield, Mangeshrak Basin, Kazakhstan

Zhao

Liao

et al. 2022

Energies

View full text Add to dashboard Cite

Three-dimensional (3D) seismic data and well log data were used to investigate the sandstone architecture of the Middle Jurassic deltaic reservoirs of the Zhetybay Oilfield, Mangeshrak Basin, Kazakhstan. The base-level cycles of different scales were identified and divided using well log and 3D seismic data. Five types of sedimentary boundaries were identified in the mouth bar sandstones. The boundaries divide single mouth bars. Vertically, the spatial distribution of sand bodies can be divided into superposed, spliced, and isolation modes. Laterally, contact modes can be divided into superposition, lateral, and isolation modes. We found that the base-level cycle controls the evolution of the delta front sand body architecture. In the early decline or late rise of the base-level cycle, the superimposed or spliced modes dominate the sand body. By contrast, the lateral or isolation modes dominate the sand body in the late decline or early rise of the base-level cycle. This paper proposes an architecture model of the delta front sand bodies controlled by the base-level cycle. The spatial distribution and morphological variation of deltaic sand bodies could be linked to the base-level cycles.

show abstract

“…Importantly, most of the values obtained by this method are the present-day lower critical limits of the reservoir, but not the lower physical limits of the reservoir at the time of formation. Besides, the reservoir formation process is not considered, and the value is often fixed at a certain level in a specific area, which is not consistent with reality (Purcell, 1949;Wu et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Criteria and favorable distribution area prediction of Paleogene effective sandstone reservoirs in the Lufeng Sag, Pearl River Mouth Basin

Wang

Chen

et al. 2022

Adv. Geo-Energy Res.

View full text Add to dashboard Cite

As the focus of conventional oil and gas exploration is changing from shallow to deep layers, the identification of deep effective reservoirs is crucial to exploration and development. In this paper, based on the geological anatomy of oil and gas reservoirs, a new discriminatory criterion and evaluation method for effective reservoirs is proposed in combination with the analysis of reservoir formation dynamics mechanism. The results show that the hydrocarbon properties of the reservoir vary with the ratio of the capillary force between the sandstone reservoir and its surrounding rock. The effective reservoir is discriminated and the reservoir quality is evaluated based on the capillary force and depth of the surrounding media and the sandstone reservoir for adjacent plates. When the capillary force ratio is greater than 0.6, fewer effective reservoirs are developed. The effective reservoir is determined by the capillary force ratio of the sandstone reservoir and the surrounding rock medium to mechanically explain the geological phenomenon that low-porosity reservoirs can also accumulate hydrocarbons. Our findings have significant guiding value for Paleogene oil and gas exploration in the Zhu I depression of Pearl River Mouth Basin.

show abstract

Seismic sedimentology, facies analyses, and high-quality reservoir predictions in fan deltas: A case study of the Triassic Baikouquan Formation on the western slope of the Mahu Sag in China's Junggar Basin

Cited by 29 publications

References 26 publications

Analysis of Factors of Productivity of Tight Conglomerate Reservoirs Based on Random Forest Algorithm

Analysis of Factors of Productivity of Tight Conglomerate Reservoirs Based on Random Forest Algorithm

Sedimentary Architecture Analysis of Deltaic Sand Bodies Using Sequence Stratigraphy and Seismic Sedimentology: A Case Study of Jurassic Deposits in Zhetybay Oilfield, Mangeshrak Basin, Kazakhstan

Criteria and favorable distribution area prediction of Paleogene effective sandstone reservoirs in the Lufeng Sag, Pearl River Mouth Basin

Contact Info

Product

Resources

About