Experimental study and field verification of fracturing technique using a thermo-responsive diverting agent

Chen, Xiang; Zhao, Liqiang; Liu, Pingli; Du, Juan; Wang, Qiang; Qi, An; Chang, Bei; Luo, Zhifeng; Zhang, Nanlin

doi:10.1016/j.jngse.2021.103993

Cited by 17 publications

(10 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fracture conductivity of igneous rocks is strong, and the pressure penetration of the drilling fluid along the fracture further affects wellbore stability. 18 , 19 …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Study on Rock Mechanics and Wellbore Stability of Igneous Formation in the Shunbei Area

et al. 2022

View full text Add to dashboard Cite

While drilling into the igneous rock formations of the Shunbei area, problems such as loss of well circulation and borehole collapse occur frequently, seriously hindering the efficient development of oil and gas resources. Aiming to solve this problem, the physicochemical and mechanical properties of igneous rocks are studied through a series of laboratory tests to determine the main factors influencing formation collapse and instability. In addition to the laboratory results, the weak plane effect of fracture mechanics, the seepage effect of drilling fluid, and the hydration effect of the drilling fluid on the borehole wall stability of igneous rock formations are evaluated and analyzed by establishing a mathematical model. The results show that the microfractures in the igneous rock are relatively developed and can be divided into unfilled fractures and calcite-filled fractures. The mechanical strength of the matrix igneous rock is higher than that of the rock samples with microfractures. The compressive strength of calcite-filled and unfilled fracture samples is 1/3–1/4 that of matrix igneous rocks, and immersion in the drilling fluid has little influence on the mechanical strength of igneous rocks. The fracture weak plane effect has the greatest influence on wellbore stability. With the increase of the number of fractures at different angles, the collapse pressure equivalent density of the formation subject to the mechanical weak plane effect increases by 21% compared with that of the homogeneous formation without fractures. The seepage effect of the drilling fluid on borehole stability is secondary, and the equivalent density of the formation collapse pressure increases by 11%. Because of the low content of clay minerals, the hydration effect of the drilling fluid on borehole stability was minimal and the equivalent density of collapse pressure increased by only 2%. During the drilling process, considering the weak plane effect of the microfractures and the seepage effect of the drilling fluid, the drilling fluid density should be controlled at about 1.82 g/cm 3 . The effective plugging ability and rheological properties of the drilling fluid should be improved for the formation with microfractures. The research results can provide a theoretical basis for the safe and efficient development of igneous reservoirs.

show abstract

“…The fracture conductivity of igneous rocks is strong, and the pressure penetration of the drilling fluid along the fracture further affects wellbore stability. 18 , 19 …”

Section: Resultsmentioning

confidence: 99%

“…The fractures in igneous rocks are relatively developed, and the mechanical weak plane effect of the fractures is the main factor affecting borehole wall collapse. The fracture conductivity of igneous rocks is strong, and the pressure penetration of the drilling fluid along the fracture further affects wellbore stability. , …”

Section: Resultsmentioning

confidence: 99%

Study on Rock Mechanics and Wellbore Stability of Igneous Formation in the Shunbei Area

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Hydraulic fracturing is an effective technique for stimulating low-permeability and ultralow-permeability oil and gas reservoirs. − A large amount of fracturing fluid is pumped to the bottomhole under high pressure to form the induced fractures, and the proppant is carried and transported into the fractures. The proppant located in the fractures will prevent the fractures from fully closing after fracturing operation, , resulting in a channel with permeability several orders of magnitude higher than the permeability of the formation itself. − The viscosity and elastic properties of the fracturing fluid are crucial for creating the designed fracture geometry and controlling the suspension efficiency of proppants. − Therefore, a reasonable selection of fracturing fluid is very important in hydraulic fracturing treatment.…”

Section: Introductionmentioning

confidence: 99%

Review on High-Temperature-Resistant Viscoelastic Surfactant Fracturing Fluids: State-of-the-Art and Perspectives

Liu

et al. 2023

Energy Fuels

Self Cite

View full text Add to dashboard Cite

A viscoelastic surfactant (VES) fluid is an important part of a water-based fracturing fluid. As oil and gas exploration expands into deep, high-temperature, low-permeability reservoirs, the conventional VES fracturing fluid has shown great limitations. The high-temperature-resistance mechanisms of the high-temperature-resistant VES fracturing fluids in publicly available literature were analyzed from five aspects: single-chain surfactant system, oligomeric surfactant system, counterion effect, blended surfactant system, and nano-enhanced VES system. The friction-reduction performance, sand-carrying performance, gel-breaking performance, and core-damage performance of these systems were summarized. The results show that oligomeric surfactants with a monounsaturated hydrophobic long chain (>C21) are most likely to be used for VES fracturing fluids in high-temperature reservoirs, but the loading of the surfactants is still relatively high (3–5 wt %). By reducing the repulsion among polar headgroups to effectively decrease the area of head groups, or/and penetrating into the nonpolar cores based on hydrophobic interaction to increase the average hydrophobic volume of hydrophobic tails, counterions affect the performance of VESs. The aromatic counterion salts are preferred choices for improving the temperature resistance, friction reduction, and suspended sand performance of VES fluids. The blended surfactant/synthetic polymer systems based on noncovalent interaction improve the temperature resistance of VES fluids and reduce the loading of the surfactants to a certain extent. Based on the “pseudo-cross-linking” of nanomaterials and wormlike micelles, a very small amount of nanomaterials can improve the temperature resistance of VES fluids and reduce the loading of the surfactants. The most essential and effective method to improve the temperature resistance of VES fluids for fracturing is the molecular structure design based on the packing parameter theory. However, the synthesis process or route still needs further optimization to reduce production costs. In addition, given the excellent performance of VES fluids enhanced by nanomaterials, further research should be conducted on the influence mechanism of nanomaterial type and geometric features on the performance of VESs, as well as the potential harmfulness of nanomaterials, to promote the field-scale application of nano-enhanced VES fluids.

show abstract

“…Hydraulic fracturing or acid fracturing, as one of the important technologies for reservoir stimulation, has been tested and gradually popularized in the oilfield since the 1940s. , So far, hydraulic fracturing and acid fracturing have become necessary technologies for the exploitation of tight oil or gas, shale oil or gas, coalbed methane, and gas hydrate. − Fracture height is one of the essential parameters to describe fracture geometry. It is the input parameter of the two-dimensional fracturing model or the output parameter of the three-dimensional fracturing model, which affects the accuracy of fracturing model calculation results and ultimately affects fracturing treatment design, safety, and economy. − Therefore, precise prediction of the fracture height is a significant task for fracturing stimulation.…”

Section: Introductionmentioning

confidence: 99%

Numerical Modeling of Fracture Height Propagation in Multilayer Formations Considering the Plastic Zone and Induced Stress

Chen

Liu

et al. 2022

ACS Omega

Self Cite

View full text Add to dashboard Cite

Hydraulic fracturing and acid fracturing are very effective stimulation technologies and are widely used in unconventional reservoir development. Fracture height, as an essential parameter to describe the geometric size of a fracture, is not only the input parameter of two-dimensional fracturing models but also the output parameter of three-dimensional fracturing models. Accurate prediction of fracture height growth can effectively avoid some risks. For example, petroleum reservoirs produce a large amount of formation water because wrong fracture height prediction leads to the connection between the oil or gas reservoir and the water layer. Although some fracture height prediction models were developed, few models considered the effects of the plastic zone, induced stress, and heterogeneous multilayer formation and its interaction. Therefore, considering the influence of many factors, an improved fracture-equilibrium-height model was developed in this study. The successive over-relaxation iteration method and the displacement discontinuity method were used to solve the model. We investigated the effects of the geological and engineering factors on fracture height growth by using the model, and some important conclusions were obtained. The higher the fracture height, the larger the plastic zone size, and the more obvious its influence on fracture height propagation. High overlying or underlying in situ stress and fracture toughness and low fluid density played a positive role in limiting the growth of the fracture height. Induced stress caused by fracture 1 could not only inhibit the height growth of fracture 2 but also promote its growth. The model established in this paper could be coupled to a fracturing simulator to provide a more reliable fracture height prediction.

show abstract

Experimental study and field verification of fracturing technique using a thermo-responsive diverting agent

Cited by 17 publications

References 20 publications

Study on Rock Mechanics and Wellbore Stability of Igneous Formation in the Shunbei Area

Study on Rock Mechanics and Wellbore Stability of Igneous Formation in the Shunbei Area

Review on High-Temperature-Resistant Viscoelastic Surfactant Fracturing Fluids: State-of-the-Art and Perspectives

Numerical Modeling of Fracture Height Propagation in Multilayer Formations Considering the Plastic Zone and Induced Stress

Contact Info

Product

Resources

About