Polymer Drilling Fluid with Micron-Grade Cenosphere for Deep Coal Seam

Traditional shallow coal seam uses clean water, solid-free system, and foam system as drilling fluid, while they are not suitable for deep coal seam drilling due to mismatching density, insufficient bearing capacity, and poor reservoir protection effect. According to the existing problems of drilling fluid, micron-grade cenosphere with high bearing capacity and ultralow true density is selected as density regulator; it, together with polymer “XC + CMC” and some other auxiliary agents, is jointly used to build micron-grade polymer drilling fluid with cenosphere which is suitable for deep coal seam. Basic performance test shows that the drilling fluid has good rheological property, low filtration loss, good density adjustability, shear thinning, and thixotropy; besides, drilling fluid flow is in line with the power law rheological model. Compared with traditional drilling fluid, dispersion stability basically does not change within 26 h; settlement stability evaluated with two methods only shows a small amount of change; permeability recovery rate evaluated with Qinshui Basin deep coal seam core exceeds 80%. Polymer drilling fluid with cenosphere provides a new thought to solve the problem of drilling fluid density and pressure for deep coal seam drilling and also effectively improves the performance of reservoir protection ability.

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The Test of Amine Polymeric Alcohol Drilling Fluid System in Baka Block

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.268-270.614 ◽

2012 ◽

Vol 268-270 ◽

pp. 614-617

Author(s):

Yu Xue Sun ◽

Bo Xu ◽

Yu Ning Xie

Keyword(s):

Coal Seam ◽

Shear Force ◽

Drilling Fluid ◽

Strong Inhibition ◽

Fluid System ◽

Thick Coal Seam ◽

Recovery Test ◽

Jurassic Coal ◽

Tertiary Recovery ◽

Reservoir Protection

2500 meters below Baka block appears extremely thick coal seam and distributed long, unconsolidated and mixed up with carbonaceous mudstone between beds. The relieved stress after a new borehole is drilled will lead to the wellbore caving and peeling and finally form an approximate elliptic borehole, causing vicious accidents such as bit bouncing, bit freezing while tripping and even borehole discarding. The anti-sloughing capability of Amine Polymeric Alcohol (AP-1) was evaluated by tertiary recovery test and core immersing test, the formula of Amine Polymeric Alcohol drilling fluid system was also optimized. Indoor research shows that the drilling fluid is of strong inhibition and pollution resistance. Its plastic viscosity is 24 mPa•s, shear force is 11 Pa and permeability recovery value reached（81.9-89.6）%. The successful test in Ke 21 Ping 1 well indicates that Amine Polymeric Alcohol drilling fluid system with powerful inhibition can effectively solve the collapse of Jurassic coal seam and carbonaceous mudstone, present high lubricity and can improve the drilling speed effectively, meanwhile, it performances well in gaining reservoir protection, controlling drilling fluid rheological properties, enhancing pollution resistance and reducing the occurrence of complex accidents downhole. Thus it can provide reference for future drilling operation in sloughing formations.

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Minimizing the filtration loss of water-based drilling fluid with sustainable basil seed powder

Petroleum ◽

10.1016/j.petlm.2021.02.001 ◽

2021 ◽

Author(s):

Hanyi Zhong ◽

Xin Gao ◽

Xianbin Zhang ◽

Anliang Chen ◽

Zhengsong Qiu ◽

...

Keyword(s):

Drilling Fluid ◽

Filtration Loss ◽

Water Based

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Laboratory Study on Core Fracturing Simulations for Wellbore Strengthening

Geofluids ◽

10.1155/2019/7942064 ◽

2019 ◽

Vol 2019 ◽

pp. 1-18 ◽

Cited By ~ 3

Author(s):

Biao Ma ◽

Xiaolin Pu ◽

Zhengguo Zhao ◽

Hao Wang ◽

Wenxin Dong

Keyword(s):

Bearing Capacity ◽

Laboratory Study ◽

Drilling Fluid ◽

Drilling Fluids ◽

Lost Circulation ◽

The Core ◽

Fracture Pressure ◽

Fluid Systems ◽

Fracturing Process ◽

Wellbore Strengthening

The lost circulation in a formation is one of the most complicated problems that have existed in drilling engineering for a long time. The key to solving the loss of drilling fluid circulation is to improve the pressure-bearing capacity of the formation. The tendency is to improve the formation pressure-bearing capacity with drilling fluid technology for strengthening the wellbore, either to the low fracture pressure of the formation or to that of the naturally fractured formation. Therefore, a laboratory study focused on core fracturing simulations for the strengthening of wellbores was conducted with self-developed fracture experiment equipment. Experiments were performed to determine the effect of the gradation of plugging materials, kinds of plugging materials, and drilling fluid systems. The results showed that fracture pressure in the presence of drilling fluid was significantly higher than that in the presence of water. The kinds and gradation of drilling fluids had obvious effects on the core fracturing process. In addition, different drilling fluid systems had different effects on the core fracture process. In the same case, the core fracture pressure in the presence of oil-based drilling fluid was less than that in the presence of water-based drilling fluid.

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Improving the rheological properties of water-based calcium bentonite drilling fluids using water-soluble polymers in high temperature applications

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0205 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Jinliang Liu ◽

Fengshan Zhou ◽

Fengyi Deng ◽

Hongxing Zhao ◽

Zhongjin Wei ◽

...

Keyword(s):

High Temperature ◽

Rheological Properties ◽

Apparent Viscosity ◽

Drilling Fluid ◽

Shear Thickening ◽

Water Soluble ◽

Drilling Fluids ◽

Drilling Depth ◽

Filtration Loss ◽

Calcium Bentonite

Abstract Most of bentonite used in modern drilling engineering is physically and chemically modified calcium bentonite. However, with the increase of drilling depth, the bottom hole temperature may reach 180 °C, thus a large amount of calcium bentonite used in the drilling fluid will be unstable. This paper covers three kinds of calcium bentonite with poor rheological properties at high temperature, such as apparent viscosity is greater than 45 mPa·s or less than 10 mPa·s, API filtration loss is greater than 25 mL/30 min, which are diluted type, shear thickening type and low-shear type, these defects will make the rheological properties of drilling fluid worse. The difference is attributed to bentonite mineral composition, such as montmorillonite with good hydration expansion performance. By adding three kinds of heat-resistant water-soluble copolymers Na-HPAN (hydrolyzed polyacrylonitrile sodium), PAS (polycarboxylate salt) and SMP (sulfomethyl phenolic resin), the rheological properties of calcium bentonite drilling fluids can be significantly improved. For example, the addition of 0.1 wt% Na-HPAN and 0.1 wt% PAS increased the apparent viscosity of the XZJ calcium bentonite suspension from 4.5 to 19.5 mPa·s at 180 °C, and the filtration loss also decreased from 20.2 to 17.8 mL.

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Biomass Activated Carbon from Oil Palm Shell as Potential Material to Control Filtration Loss in Water-Based Drilling Fluid

Optimization Based Model Using Fuzzy and Other Statistical Techniques Towards Environmental Sustainability ◽

10.1007/978-981-15-2655-8_4 ◽

2020 ◽

pp. 55-65

Author(s):

Mursyidah Umar ◽

Arif Rahmadani Amru ◽

Nur Hadziqoh Muhammad Amin ◽

Hasnah M. Zaid ◽

Beh Hoe Guan

Keyword(s):

Activated Carbon ◽

Oil Palm ◽

Drilling Fluid ◽

Palm Shell ◽

Oil Palm Shell ◽

Filtration Loss ◽

Water Based

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Mechanical Modeling of Roof Fracture Instability Mechanism and Its Control in Top-Coal Caving Mining under Thin Topsoil of Shallow Coal Seam

Advances in Civil Engineering ◽

10.1155/2019/1986050 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Peilin Gong ◽

Tong Zhao ◽

Kaan Yetilmezsoy ◽

Kang Yi

Keyword(s):

Coal Seam ◽

Mechanical Model ◽

Main Roof ◽

Stability Control ◽

Hydraulic Support ◽

Rock Stability ◽

Shallow Coal Seam ◽

Minimum Height ◽

The Stability ◽

Working Resistance

This study aimed to explore the safe and efficient top-coal caving mining under thin topsoil of shallow coal seam (SCS) and realize the optimization of hydraulic support. Numerical simulation and theoretical analysis were used to reveal the stress distribution of the topsoil, the structure characteristics of the main roof blocks, and the development of the roof subsidence convergence. Step subsidence of the initial fractured main roof after sliding destabilization frequently existed, which seriously threatened the safety of the hydraulic supports. Hence, a mechanical model of the main roof blocks, where the topsoil thickness was less than the minimum height of the unloading arch, was established, and the mechanical criterion of the stability was achieved. The working resistance of the hydraulic support was calculated, and the reasonable type was optimized so as to avoid crushing accident. Findings of the present analysis indicated that the hydraulic support optimization was mainly affected by fractured main roof blocks during the first weighting. According to the block stability mechanical model based on Mohr–Coulomb criterion, the required working resistance and the supporting intensity were determined as 4899 kN and 0.58 MPa, respectively. The ZZF5200/19/32S low-position top-coal caving hydraulic support was selected for the studied mine and support-surrounding rock stability control of thin-topsoil SCS could be achieved without crushing accident.

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