scholarly journals Damage Mechanism of Oil-Based Drilling Fluid Flow in Seepage Channels for Fractured Tight Sandstone Gas Reservoirs

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Peng Xu ◽  
Mingbiao Xu
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Damage Mechanism ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Stabilization Effect ◽  
Potential Damage ◽  
Physical And Chemical

Oil-based drilling fluids (OBDFs) have a strong wellbore stabilization effect, but little attention has been paid to the formation damage caused by oil-based drilling fluids based on traditional knowledge, which is a problem that must be solved prior to the application of oil-based drilling fluid. For ultradeep fractured tight sandstone gas reservoirs, the reservoir damage caused by oil-based drilling fluids is worthy of additional research. In this paper, the potential damage factors of oil-based drilling fluids and fractured tight sandstone formations are analyzed theoretically and experimentally. The damage mechanism of oil-based drilling fluids for fractured tight sandstone gas reservoirs is analyzed based on the characteristics of multiphase fluids in seepage channels, the physical and chemical changes of rocks, and the rheological stability of oil-based drilling fluids. Based on the damage mechanism of oil-based drilling fluids, the key problems that must be solved during the damage control of oil-based drilling fluids are analyzed, a detailed description of formation damage characteristics is made, and how to accurately and rapidly form plugging zones is addressed. This research on damage control can provide a reference for solving the damage problems caused by oil-based drilling fluids in fractured tight sandstone gas reservoirs.

Multiscale Formation Damage Mechanisms and Control Technology for Deep Tight Clastic Gas Reservoirs

SPE Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Yijun Wang ◽  
Yili Kang ◽  
Lijun You ◽  
Chengyuan Xu ◽  
Xiaopeng Yan ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Production Capacity ◽  
Damage Mechanism ◽  
Field Application ◽  
Formation Damage ◽  
Fluid Loss ◽  
Drilling Process ◽  
Gas Reservoirs ◽  
Filtration Loss

Summary Severe formation damage often occurs during the drilling process, which significantly impedes the timely discovery, accurate evaluation, and efficient development of deep tight clastic gas reservoirs. The addition of formation protection additives into drilling fluid after diagnosing the damage mechanism is the most popular technique for formation damage control (FDC). However, the implementation of traditional FDC measures does not consider the multiscale damage characteristics of the reservoir. The present study aims at filling this gap by providing a complete and systematic damage control methodology based on multiscale FDC theory. First, the characteristics of multiscale seepage channels were described through petrology, petrophysics, and well-history data. Subsequently, based on laboratory formation damage evaluation experiments, the formation damage mechanism of each seepage scale was determined. Finally, based on the multiscale formation damage mechanism, a systematic multiscale FDC technology was proposed. Through the use of optimized drilling fluid based on multiscale FDC theory, high-permeability recovery ratio (PRR), high-pressure bearing capacity of plugging zone, and low cumulative filtration loss were observed by laboratory validation experiments. Shorter drilling cycle, less drill-in-fluid loss, lower skin factor, and higher production rates were obtained by using the optimized FDC drilling fluid in field application. This multiscale FDC theory shows excellent results in minimizing formation damage, maintaining original production capacity, and effectively developing gas reservoirs with multiscale pore structure characteristics.

The "U-Type" Wells History of Fuzzy Ball Drilling Fluids for CBM Drilling in China

2013 ◽  
Vol 748 ◽  
pp. 1273-1276 ◽  
Author(s):  
Ben Guang Guo ◽  
Li Hui Zheng ◽  
Shang Zhi Meng ◽  
Zhi Heng Zhang
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Ordos Basin ◽  
Coal Bed ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Horizontal Section ◽  
Lost Circulation ◽  
Well Bore Stability ◽  
Formation Damage Control

The fuzzy ball drilling fluids have been developed on the basis of the circulation foam and Aphron to control lost circulation effectively. There are some difficulties in drilling U-type well, such as well-bore stability, cutting carrying problem, large torque and friction at the horizontal section, and formation damage to coal-bed. The objective of this paper was to show some applications of fuzzy ball drilling fluids on U-type wells of the Ordos Basin and prove the superiority of fuzzy ball drilling fluid in CBM drilling. To the three mentioned cases, the density of fuzzy ball drilling fluid was 0.90~1.18g/cm3, the funnel viscosity was 45~72s, the dynamic shear force was 12~19 Pa, the PV was 13~19mPa·s and the pH was ranged from 7 to 9. To use the fuzzy ball drilling fluids, the average ROP increased above 10% with no borehole complexity, such as stuck pipe, hole enlargement causing poor cleaning and etc. These cases reflected excellent properties of the fuzzy ball drilling fluids including effectively sealing, good carrying and suspension ability, formation damage control and compatible weighted by inert materials. Furthermore, the fuzzy ball drilling fluids will not affect BHA tools like motors and MWD in CBM drilling.

scholarly journals Experimental study on thermal, rheological and filtration control characteristics of drilling fluids: effect of nanoadditives

2020 ◽  
Vol 75 ◽  
pp. 36
Author(s):  
Erfan Veisi ◽  
Mastaneh Hajipour ◽  
Ebrahim Biniaz Delijani
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Drill Bit ◽  
Rheological Characteristics ◽  
Cu Nanoparticles ◽  
Water Based

Cooling the drill bit is one of the major functions of drilling fluids, especially in high temperature deep drilling operations. Designing stable drilling fluids with proper thermal properties is a great challenge. Identifying appropriate additives for the drilling fluid can mitigate drill-bit erosion or deformation caused by induced thermal stress. The unique advantages of nanoparticles may enhance thermal characteristics of drilling fluids. The impacts of nanoparticles on the specific heat capacity, thermal conductivity, rheological, and filtration control characteristics of water‐based drilling fluids were experimentally investigated and compared in this study. Al2O3, CuO, and Cu nanoparticles were used to prepare the water-based drilling nanofluid samples with various concentrations, using the two-step method. Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) were utilized to study the nanoparticle samples. The nanofluids stability and particle size distribution were, furthermore, examined using Dynamic Light Scattering (DLS). The experimental results indicated that thermal and rheological characteristics are enhanced in the presence of nanoparticles. The best enhancement in drilling fluid heat capacity and thermal conductivity was obtained as 15.6% and 12%, respectively by adding 0.9 wt% Cu nanoparticles. Furthermore, significant improvement was observed in the rheological characteristics such as the apparent and plastic viscosities, yield point, and gel strength of the drilling nanofluids compared to the base drilling fluid. Addition of nanoparticles resulted in reduced fluid loss and formation damage. The permeability of filter cakes decreased with increasing the nanoparticles concentration, but no significant effect in filter cake thickness was observed. The results reveal that the application of nanoparticles may reduce drill-bit replacement costs by improving the thermal and drilling fluid rheological characteristics and decrease the formation damage due to mud filtrate invasion.

Basic Performance Research of Polymer Intercalation Clay

2012 ◽  
Vol 578 ◽  
pp. 183-186
Author(s):  
Xiao Chun Cao ◽  
Yi Qin ◽  
Yan Na Zhao ◽  
Kun Ke
Keyword(s):  
Drilling Fluid ◽  
Chemical Properties ◽  
Drilling Fluids ◽  
Technical Problems ◽  
Clay Particles ◽  
Polymer Properties ◽  
Physical And Chemical ◽  
Performance Research ◽  
And Chemical Properties

Using the preliminary research of the polymer properties, the different between the physical and chemical properties of new polymer-clays nanometer composites and clay have been studied. Different polymers are used to evaluate experiment. Based on a large number of lab experiments, the changes of rheological property and API filtration property of polymer-clay drilling fluids nanometer composites are studied. The results show that clay particles could become smaller and the composites drilling fluid have the role of controlling loss and enhancing cake quality. The prepared composites could be used to solve the technical problems in drilling fluid.

scholarly journals Formation Damage Avoidance by Reducing Invasion with Sodium Silicate-Modified Water-Based Drilling Fluid

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1485 ◽  
Author(s):  
Salaheldin Elkatatny ◽  
Tural Jafarov ◽  
Abdulaziz Al-Majed ◽  
Mohamed Mahmoud
Keyword(s):  
Rheological Properties ◽  
Sodium Silicate ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Ct Scanner ◽  
Tight Sandstone ◽  
Ct Number ◽  
Mechanical Removal ◽  
Before And After

Drilling multilateral and horizontal wells through tight gas reservoirs is a very difficult task. The drilling fluid should be designed to reduce both fluid and solid invasion into the tight formation to avoid formation damage by aqueous phase trapping. The objective of this paper is to assess the effect of sodium silicate on the drilling fluid properties such as rheological and filtration properties. Rheological properties (RPs) were measured at different temperatures while the filtration test was performed at 300 °F and 300 psi differential pressure. A retained permeability calculation was determined to confirm the prevention of solid invasion. The rheological properties results confirmed that the optimal concentration of sodium silicate (SS) was 0.075 wt.% and at the same time, the temperature has no effect on the SS optimum concentration. Using 0.075 wt.% of SS reduced the filtrate volume by 53% and decreased the filter cake thickness by 65%. After mechanical removal of the filter cake, the return permeability of the tight sandstone core was 100% confirming the prevention of solid invasion. The computer tomography (CT) scanner showed that the CT number before and after the filtration test was very close (almost the same) indicating zero solid invasion and prevention of the formation damage.

Application of modified starch in high-temperature-resistant colloidal gas aphron (CGA) drilling fluids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxi Zhu ◽  
Xiuhua Zheng
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
High Performance ◽  
Oil And Gas ◽  
Elevated Temperatures ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Modified Starch ◽  
Gas Reservoirs ◽  
Building Capability

Abstract Colloidal gas aphrons (CGA) are finding increasing application in depleted oil and gas reservoirs because of their distinctive characteristics. To overcome the limitations of its application in high-temperature drilling, a modified starch foams stabilizer WST with a temperature resistance of 160 °C was synthesized via radical polymerization. The chemical structure of WST was characterized by Fourier infrared spectroscopy and results showed that all three monomers acrylamide, 2-acrylamido-2-methyl-1-propane sulfonic acid, and N-vinylpyrrolidone have been grafted onto starch efficiently. Based on the microscopic observations, highly stable aphrons have been successfully generated in the WST-based CGA drilling fluids within 160 °C, and most aphrons lie in the range of 10–150 μm. WST can provide higher viscosity at high temperatures compared to xanthan gum, which helps to extend foam life and stability by enhancing the film strength and slowing down the gravity drainage. Results show that WST-CGA aged at elevated temperatures (120–160 °C) is a high-performance drilling fluid with excellent shear-thinning behavior, cutting carrying capacity, and filtration control ability. The significant improvement of filtration control and well-building capability at high temperatures is an important advantage of WST-CGA, which can be attributed to the enhancement of mud cake quality by WST.

Fuzzy Ball Drilling Fluid for CBM in the Ordos Basin of China

2013 ◽  
Vol 651 ◽  
pp. 717-721 ◽  
Author(s):  
Jin Feng Wang ◽  
Jin Gen Deng
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Ordos Basin ◽  
Drilling Fluids ◽  
Auxiliary Equipment ◽  
Lost Circulation ◽  
Zone Control ◽  
Open Hole ◽  
Air Drilling ◽  
Formation Damage Control

Fuzzy ball drilling fluids have been developed in order to effectively control lost circulation during CBM drilling. Depending upon fuzzy balls and colloids in fuzzy balls, the fuzzy ball drilling fluids changed their shapes and properties to completely plug underground heterogeneous seepage channels so as to strengthen the pressure bearing capacity of formations. This paper describes the available features of the fuzzy ball drilling fluid including efficient plugging, good carrying and suspension, formation damage control, compatible weighted by any weighted materials without auxiliary equipment. The fuzzy ball drilling fluids can finish drilling in low pressure natural gas zone, control CBM leakage; control the natural fractures, drilling in different pressures in the same open hole, combination with the air drilling mode, etc. during Ordos CBM drilling. The fuzzy ball drilling fluid will not affect down-hole motors and MWD. The fuzzy ball drilling fluid will be blend simply as conventional water based drilling fluids. The existing CBM drilling equipment can completely meet the fuzzy ball drilling mixing and it is maintained conveniently. The fuzzy ball drilling fluid is the efficient drilling fluid.

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