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.

Influence of Rock Chemical Composition in Microwave Heating and Decontamination of Drill Cuttings

2017 ◽  
Vol 899 ◽  
pp. 469-473 ◽  
Author(s):  
Irineu Petri Jr. ◽  
Jéssika Marina dos Santos ◽  
Arley Silva Rossi ◽  
Marina Seixas Pereira ◽  
Claudio Roberto Duarte ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Electromagnetic Waves ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Microwave Drying ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Heating Unit ◽  
Drill Cuttings ◽  
Gas Drilling

Drill cuttings generated by oil and gas drilling process are incorporated into the drilling fluid to ensure an efficient drilling and solids removal. The drilling rigs have a separation system accountable for separating drill cuttings and drilling fluids. Microwave drying is a new technology of separation that has been studied as an alternative to the currently drill cuttings dryer used. The results obtained in preliminary studies showed that this microwave drying is sensitive to different oxides presents into the rock. Thus, this study aimed to describe the microwave heating kinetics of some rocks in order to verify the interaction of oxides with electromagnetic waves. For this, the oxide contents of the rocks were determined by X-ray Fluorescence and different rocks were heated in a microwave heating unit. The results showed that the relationship between the temperature and heating time is exponential and depends on the rock oxide contents. It was found that the iron oxides may be unstable at microwave and rocks with high levels of magnesium oxides and sulfates tend to be good absorbers of microwave. Rocks containing high levels of calcium, silicon, titanium, barium and chloride (NaCl) are not good absorbers of microwave. It was also noted that faster solid heating, lesser the efficiency of microwave drying.

scholarly journals The effective application of mud cooler machine to support to carry out the infill wells in Cuu Long basin

2021 ◽  
Vol 62 (3a) ◽  
pp. 76-84
Author(s):  
Tuan Tran Nguyen ◽  
Son Hoang Nguyen ◽  
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Drilling Process ◽  
Fluid Temperature ◽  
Gas Drilling ◽  
Drilling Rig ◽  
Effective Application ◽  
Safe Level ◽  
Fluid Properties ◽  
Temperature And Pressure

This paper presents some studies on the application of mud cooler in Oil and Gas drilling in a high temperature, high pressure condition of Cuu Long reservoir. The authors have proposed a method to study the theory of temperature effects on drilling fluid properties, that have been tested practically. The authors have remarked on each type of drilling rig and installation location. With these remarks, the authors give an option to install the "Mud cooler" on the rig at the appropriate location and method so that the temperature of the solution will be ensured to reduce to a safe level. The effective application of this equipment has greatly assisted drilling process since the fluid temperature has been reduced sharply before returning to the mud tank. This has helped cut down expenses significantly by prolonging eqipment's endurability, saving time for drilling, ship renting, drilling services and minimize the budget spent on buying the fluid and additives to recover it. Thus, the drilling workers' working conditions have been facilitated. The results of these studies have been proved scientifically and practically through the successful drilling of well ST-3P-ST. This will make the way for other local wells and reservoirs which have the same conditions of temperature and pressure.

scholarly journals A temperature-pressure coupling model for predicting gas temperature profile in gas drilling

2020 ◽  
pp. 193-193
Author(s):  
Jinjiang Liu ◽  
Wenlin Wu ◽  
Peng Qian ◽  
Shuo Wang
Keyword(s):  
Temperature Profile ◽  
Drilling Fluid ◽  
Physical Parameters ◽  
Drilling Process ◽  
Gas Temperature ◽  
Gas Drilling ◽  
Bottom Hole ◽  
Pump Rate ◽  
Nozzle Size ◽  
Wellbore Temperature

In the gas drilling design, accurate prediction of wellbore temperature profile is very crucial. Different from liquid drilling fluid, physical and thermo-physical parameters of gases are sensitive to the change of pressure and temperature, at the same time, the change of these parameters will react against the wellbore temperature and pressure. Based on the energy conservation principle, a temperature-pressure coupling calculation model was established to predict the gas temperature profile during gas drilling process. The model is solved by cycle coupling iteration method. The calculation shows that annular temperature rises sharply near the wellhead, drops sharply at bottom hole and is a little higher than the formation temperature in other places. Without considering the influence of friction heat, calculated temperature is lower than the actual temperature. Temperature trends are the same under different pump rates and larger pump rate leads to larger temperature range at the wellhead and at bottom hole. Compared with the pump rate, bit nozzle size has more influence on the temperature drop range. Temperature reduction increases from 31.3?C to 57.2?C while bit nozzle size decreases from 539 mm2 to 339 mm2.

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.

Analysis of the Formation Mechanism of Crack Network in Shale by CT

2014 ◽  
Vol 568-570 ◽  
pp. 12-18
Author(s):  
Qing Hua Sun ◽  
Jin Gen Deng ◽  
Zhuo Chen ◽  
Yong Meng Xu ◽  
Heng Lin Yang ◽  
...  
Keyword(s):  
Shale Gas ◽  
Horizontal Well ◽  
Maximum Stress ◽  
Drilling Fluid ◽  
Fracture Plane ◽  
Chromatographic Technique ◽  
Drilling Process ◽  
Crack Network ◽  
Wellbore Instability ◽  
Shale Formation

During the drilling process of shale gas horizontal well, wellbore instability problem happens frequently. Especially in the horizontal interval, shale which has high levels of gamma is more likely to collapse which lead to delays, and exist certainly collapse period. The development of shale gas is restricted seriously. Research on the formation process of cracks network around the wellbore by CT chromatographic technique. The result reveals that under the condition of uniaxial compression, the cracks initiated inside the shale formation around the wellbore, with the propagation of cracks, between the orientation of cracks and the maximum stress direction will emerge a certain deviated angle. The drilling fluid filtrates into the formation and reduce the strength of rock which will prompt crack propagation and form crack network. Finally the wellbore will collapse with drilling fluid continuous invasion, because the invasion have altered the stress intensity factor at fracture tip, and changed the propagating direction of crack and the friction coefficient of fracture plane, which will reduce the strength of rock and the effective stress of the rock around the wellbore. Crack network dominates the mechanism of instability; mud weight increases do not necessarily lead to a more stable borehole and can further destabilize the wellbore.

Impacts of Gas Drilling on Human and Animal Health

2012 ◽  
Vol 22 (1) ◽  
pp. 51-77 ◽  
Author(s):  
Michelle Bamberger ◽  
Robert E. Oswald
Keyword(s):  
Shale Gas ◽  
Animal Health ◽  
Health Impacts ◽  
Environmental Concerns ◽  
Drilling Process ◽  
Gas Drilling ◽  
The World ◽  
Drilling Operations ◽  
Reproductive Cycles ◽  
The Impact

Environmental concerns surrounding drilling for gas are intense due to expansion of shale gas drilling operations. Controversy surrounding the impact of drilling on air and water quality has pitted industry and leaseholders against individuals and groups concerned with environmental protection and public health. Because animals often are exposed continually to air, soil, and groundwater and have more frequent reproductive cycles, animals can be used as sentinels to monitor impacts to human health. This study involved interviews with animal owners who live near gas drilling operations. The findings illustrate which aspects of the drilling process may lead to health problems and suggest modifications that would lessen but not eliminate impacts. Complete evidence regarding health impacts of gas drilling cannot be obtained due to incomplete testing and disclosure of chemicals, and nondisclosure agreements. Without rigorous scientific studies, the gas drilling boom sweeping the world will remain an uncontrolled health experiment on an enormous scale.

Modeling of Filter Cake Composition in Maximum Reservoir Contact and Extended Reach Horizontal Wells in Sandstone Reservoirs

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Mohamed Mahmoud ◽  
Badr S. Bageri ◽  
Salaheldin Elkatatny ◽  
Saleh H. Al-Mutairi
Keyword(s):  
Horizontal Well ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Material Balance ◽  
Gas Production ◽  
Circulation Rate ◽  
Drilling Process ◽  
Horizontal Section ◽  
Rock Composition ◽  
Sandstone Formation

Drilling mud should be properly designed to build an effective filter cake on the formation face during the drilling process. This filter cake should be removable to allow the oil and gas production. The need for removal increases when the liftoff pressure is high or when the formation drawdown is extremely low. An effective filter cake removal design includes the knowledge of the filter cake composition along the horizontal section. This paper, for the first time, introduces material balance model to predict the composition of the filter cake along the length of the lateral of an actual horizontal well drilled in a sandstone formation. The model is based on the material balance of two sources of solids: the first one is the drilling fluid solids and the second one is the drilled-formation solids. The mud used to drill the rock was contaminated by the drilled-formation solids. The parameters used to construct the model were composition of the mud and formation, efficiency of each separation stage, rate of penetration (ROP), and mud circulation rate. The model was validated with actual mud samples collected from different locations along the horizontal section of a sandstone formation. The model showed that the sand content in the filter cake is affected by ROP, rock composition, mud composition and volume, and efficiency of sand separation equipment. We came up with several correlations that can be used to design the drilling fluid operations in horizontal well to avoid the formation of irremovable filter cake.

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