scholarly journals Study on the Mechanism of Ionic Stabilizers on Shale Gas Reservoir Mechanics in Northwestern Hunan

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2453 ◽  
Author(s):  
Pinghe Sun ◽  
Junyi Zhu ◽  
Binkui Zhao ◽  
Xinxin Zhang ◽  
Han Cao ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Clay Minerals ◽  
Shale Gas ◽  
Drilling Fluid ◽  
Pore Wall ◽  
Mechanical Tests ◽  
Borehole Stability ◽  
Gas Drilling ◽  
New Material ◽  
Niutitang Formation

The shale of the lower Cambrian Niutitang formation in northwestern Hunan is an ideal reservoir for shale gas. There is a close connection between borehole stability and drilling fluid in shale gas drilling. Ionic stabilizer is a new type of stratum consolidation agent that inhibits the hydration expansion of clay minerals and improves mechanical strength of the borehole. The traditional idea of pore wall protection is to use drilling fluid additives to prevent shale from interacting with water. However, ionic stabilizer can change the hydrophilic of clay minerals in shale, making the particles become hydrophobic and dense, therefore, the formation stability can be enhanced simultaneously. The material used in this paper is different from the normal ionic stabilizer, some chemical bonds that have been changed in the new material called enhanced normality ionic (ENI) stabilizer. This paper utilized the shale samples those obtained from Niutitang formation to study the connection between ENI and the mechanical properties of shale. Mechanical tests and microscopic pore tests were performed on different samples which were soaked in water and the ENI with different concentrations. It has been found through tests that ENI can inhibit the development of shale pores, and as the concentration increases, the inhibition increases. In addition, as the ENI concentration increases, the uniaxial compressive strength and Young’s modulus of the shale increase, and the ratio of stability coefficients decreases. It can be concluded that the ENI can improve the mechanical strength of carbon shale, and prevent the development of rock damage. Moreover, it can improve the ability of rock to resist damage, and enhance borehole stability initiatively.

Study on Shale Gas Drilling Fluids Technology

2013 ◽  
Vol 868 ◽  
pp. 651-656
Author(s):  
Gang Xie ◽  
Ming Yi Deng ◽  
Jun Lin Su ◽  
Liang Chun Pu
Keyword(s):  
Shale Gas ◽  
Drilling Fluid ◽  
Blocking Agent ◽  
Drilling Fluids ◽  
Collapse Pressure ◽  
Gas Drilling ◽  
Advantages And Disadvantages ◽  
Water Based ◽  
Column Pressure ◽  
Shale Gas Drilling

Via discussing the advantages and disadvantages of different types of oil-based drilling fluids, the main reason why oil-based drilling fluids are less used in our country is obtained that dont form a complete series of matching technology. The essence of wellbore instability caused by using water-based drilling fluids to drill shale is analyzed that the formation collapse pressure is greater than drilling fluids column pressure. The fundamental way of controlling borehole wall stability that use water-based drilling fluids to drill shale horizontal well was proposed that deeply researched the shale hydration mechanism, developed efficient blocking agent and inhibitors and established shale gas drilling fluid suppression system, which made water-based drilling fluids have excellent performance.

Drilling Fluid Design for Shale Gas Drilling

2015 ◽  
Vol 1113 ◽  
pp. 617-624 ◽  
Author(s):  
Mohamad Safwan Zazarli Shah ◽  
Arina Sauki ◽  
Wan Zairani Wan Bakar ◽  
Nurul Aimi Ghazali ◽  
Azlinda Azizi
Keyword(s):  
Shale Gas ◽  
Negative Impact ◽  
Drilling Fluid ◽  
Past Research ◽  
Gas Drilling ◽  
Water Based ◽  
Oil Water ◽  
The Impact ◽  
Rheological Performance ◽  
Shale Gas Drilling

Shale gas nowadays is an important source of unconventional gas. The limited conventional gas supply makes the unconventional sources as a new source of gas. In this research, the aim is to design a mud formulation that can carry out essential functions of mud for shale gas drilling. Commonly for shale gas drilling, water based mud is used. However, water based mud is ineffective when dealing with water-sensitive shale. The alternative way to deal with this type of shale is using synthetic-based mud (SBM) or oil-based mud (OBM). OBM is an effective mud while drilling well. However, it is toxic and gives negative impact to environment. SBM somehow is more environmental friendly compared to oil based and ester is one of the synthetic based fluids. In order to prove this statement, a toxicity test was carried out to investigate the impact of ester based mud on selected marine life. The results of the test were compared with past research results. The ester use in this research is methyl-ester C12-C14 derived from palm oil and the mud was formulated at different oil-water ratios which are 70/30, 80/20 and 90/10, respectively and the best rheological performance can be seen at 80/20 oil-water ratio. Then, the performance of this mud had been compared to other types of mud which are sarapar-based and WBM. The findings revealed that the rheological performance of ester based mud is comparable with common based mud used for shale gas drilling. Apart from that, it is less toxic than other based mud which can maintain 60% prawn’s survival even after 96 hours exposure in 100,000 ppm of mud concentration in artificial seawater.

Integrated Workflow Solutions Deliver Breakthrough in Sichuan Shale Gas Drilling

2021 ◽  
Author(s):  
Wenzhe Li ◽  
Liang Tang ◽  
Ye Zhuang ◽  
Lu Zhang ◽  
Yifan Cai ◽  
...  
Keyword(s):  
Shale Gas ◽  
Average Rate ◽  
Drilling Fluid ◽  
Gas Production ◽  
Mitigation Strategies ◽  
Drilling Process ◽  
Mountainous Regions ◽  
Gas Drilling ◽  
Geomechanical Analysis ◽  
Delivery Efficiency

Abstract The Sichuan shale gas deposits are in remote, mountainous regions and the gas-bearing rocks are deep and in tectonically complicated areas. The plan to make shale gas account for more than 40% of the Chinese total natural gas production by 2040 requires shorter well delivery periods and higher well productions. It is therefore crucial to improve the overall drilling efficiency with the limited rig capability and geological challenges. To improve capital efficiency, a multi-disciplinary approach integrating subsurface understanding with well engineering and drilling practices was implemented. Central to this drilling optimization effort are risk mitigation strategies, utilizing solutions based on robust geomechanical understanding and critical drilling experience reviews, engineered to improve wellbore placement, drilling fluid formulation, and bit and BHA designs. A novel wellbore-strengthening oil-based mud system was implemented to maintain shale stability. A rotary steerable drilling system and reservoir navigation technology were deployed together with the application of specific poly-crystalline diamond compact (PDC) bit design. A new-generation advanced cuttings analysis method was also applied with the lithology, organic matter and fracability of rock could be evaluated in real time to assist the reservoir navigation during the drilling. This integrated solution was deployed in the drilling of 8 ½" holes of Changning Shale gas field. A cross-functional team was formed so that the operator, the drilling contractor and the service company can collaborate closely with expertise across multiple functions and disciplines. Suitable mud weight was provided by the detailed geomechanical analysis to account for the high pore pressure and near bed-parallel drilling conditions. To place the laterals in the thin targeted sub-layer with high TOC, a rotary steerable system (RSS) with azimuthal GR provide not only precise steering and directional controls, but also enable increased reservoir coverage by expanding the lateral section as well as drilling the build and horizontal sections in a single run without BHA trips. The combination of RSS with specialized bits as an optimized bit and BHA system maximizes the steering performance while delivering superior borehole quality by reducing drill string vibration and the minimizing mechanical specific energy, all of which contribute to the overall improvement in the well delivery efficiency. This integrated drilling solution has achieved remarkable results by doubling the average rate of penetration (ROP) to 15.5m/h compared to an offset well on the same pad of 7.4m/h. The well was placed successfully in the targeted zone with a 100% reservoir contact. And the total drilling time was shortened by 40% compared to similar wells nearby. The integrated solution has brought breakthrough to improve the well delivery efficiency in the China shale gas development. This paper describes the integrated workflow solutions and detailed technical optimizations of the 8 ½" section drilling process.

scholarly journals Application of Ester based Drilling Fluid for Shale Gas Drilling

2015 ◽  
Vol 83 ◽  
pp. 012012 ◽  
Author(s):  
Arina Sauki ◽  
Mohamad Safwan Zazarli Shah ◽  
Wan Zairani Wan Bakar
Keyword(s):  
Shale Gas ◽  
Drilling Fluid ◽  
Gas Drilling ◽  
Shale Gas Drilling

scholarly journals Hyperspectral analysis of shale gas drilling in southern Huangling anticline

2021 ◽  
Vol 261 ◽  
pp. 01048
Author(s):  
Pengfei Liu ◽  
Yingjun Zhao ◽  
Tianxu Guo ◽  
Hongda Zhang
Keyword(s):  
Shale Gas ◽  
Near Infrared ◽  
Short Wave ◽  
High Definition ◽  
Doushantuo Formation ◽  
Gas Drilling ◽  
Infrared Spectral ◽  
Huangling Anticline ◽  
Western Hubei ◽  
Niutitang Formation

In this paper, the visible near infrared, short wave red, and thermal infrared spectral data and high-definition core images of three wells in Huangling anticline in Western Hubei are obtained by hylogger. Through comprehensive analysis, it can be seen that the thickness of Niutitang Formation is decreasing from west to East, However, the thickness of Doushantuo Formation is basically the same, ranging from 210m to 220m. Quartz, clay minerals, carbonate and limonite are the main minerals in Niutitang formation, while in Doushantuo Formation dolomite is the main mineral. Dolomite fracture is developed in this area, which is a favorable area for shale gas development.

Solidifying Mud Cake to Improve Cementing Quality of Shale Gas Well: A Case Study

2015 ◽  
Vol 8 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Jun Gu ◽  
Ju Huang ◽  
Su Zhang ◽  
Xinzhong Hu ◽  
Hangxiang Gao ◽  
...  
Keyword(s):  
Shale Gas ◽  
Calcium Silicate Hydrate ◽  
Drilling Fluid ◽  
Cement Slurry ◽  
Gas Well ◽  
Safety Requirements ◽  
Mud Cake ◽  
Gas Bearing

The purpose of this study is to improve the cementing quality of shale gas well by mud cake solidification, as well as to provide the better annular isolation for its hydraulic fracturing development. Based on the self-established experimental method and API RP 10, the effects of mud cake solidifiers on the shear strength at cement-interlayer interface (SSCFI) were evaluated. After curing for 3, 7, 15 and 30 days, SSCFI was remarkably improved by 629.03%, 222.37%, 241.43% and 273.33%, respectively, compared with the original technology. Moreover, the compatibility among the mud cake solidifier, cement slurry, drilling fluid and prepad fluid meets the safety requirements for cementing operation. An application example in a shale gas well (Yuanye HF-1) was also presented. The high quality ratio of cementing quality is 93.49% of the whole well section, while the unqualified ratio of adjacent well (Yuanba 9) is 84.46%. Moreover, the cementing quality of six gas-bearing reservoirs is high. This paper also discussed the mechanism of mud cake solidification. The reactions among H3AlO42- and H3SiO4- from alkali-dissolved reaction, Na+ and H3SiO4- in the mud cake solidifiers, and Ca2+ and OH- from cement slurry form the natrolite and calcium silicate hydrate (C-S-H) with different silicate-calcium ratio. Based on these, SSCFI and cementing quality were improved.

scholarly journals Treatment of shale gas drilling flowback fluids (SGDFs) by forward osmosis: Membrane fouling and mitigation

Desalination ◽  
2015 ◽  
Vol 366 ◽  
pp. 113-120 ◽  
Author(s):  
Gang Chen ◽  
Zhouwei Wang ◽  
Long D. Nghiem ◽  
Xue-Mei Li ◽  
Ming Xie ◽  
...  
Keyword(s):  
Shale Gas ◽  
Membrane Fouling ◽  
Forward Osmosis ◽  
Gas Drilling ◽  
Shale Gas Drilling

scholarly journals Fast Preparation of High-Performance Wood Materials Assisted by Ultrasonic and Vacuum Impregnation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Mechanical Tests ◽  
Vacuum Impregnation ◽  
Natural Forests ◽  
Ultrasonic Pretreatment ◽  
Fast Growing ◽  
Before And After ◽  
New Material ◽  
Ft Ir

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.

Sign in / Sign up

Export Citation Format

Share Document