Well Control Technology of High Temperature and High Pressure with Different Well Shapes

2013 ◽  
Vol 316-317 ◽  
pp. 860-866
Author(s):  
Yan Jun Li ◽  
Xiang Nan He ◽  
Xiao Wei Feng ◽  
Ya Qi Zhang ◽  
Ling Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Drilling Fluid ◽  
Control Process ◽  
Formation Pressure ◽  
Well Drilling ◽  
Well Control ◽  
Direct Invasion ◽  
Bottom Hole ◽  
Gas Kick

Well control safe is the prerequisite of safety drilling, especially for high temperature and high pressure horizontal wells. However, there are few papers about well control of horizontal well drilling, which mostly learn from vertical well control process. By means of analysis of the theory of gas kick, we conclude that underbalance, the bottom hole pressure is less than the formation pressure is the main means of gas invasion. During balance period, the gas also intrudes into wellbore through the way of direct invasion, diffusion invasion and replacement invasion, but the amount of gas kick is less, so the risk of well control is small. This paper also anlyses the kick tolerance, the kick tolerance decreases with the increasing of drilling fluid density when the formation pressure and drilling equipment is constant.

Study on Multi-Functional Experimental Apparatus for the Performance Evaluation of HTHP Drilling Fluid

2011 ◽  
Vol 422 ◽  
pp. 10-16
Author(s):  
Fu Hua Wang ◽  
Rui He Wang ◽  
Xue Chao Tan
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Drilling Fluid ◽  
Dynamic State ◽  
Mechanical Transmission ◽  
Well Drilling ◽  
New Device ◽  
Deep Well ◽  
Experimental Apparatus ◽  
New Apparatus

With the development of deep well drilling technology, a new HTHP (High Temperature High Pressure) experimental apparatus LH-1 was developed to meet the need of research and evaluation of deep well drilling fluid. With the advanced dynamic seal technology, mechanical transmission and data sensing technology, this new apparatus has many kinds of HTHP testing functions in a body and could evaluate manifold performances at the dynamic state of high temperature and high pressure including HTHP dynamic or static filtration test, high temperature dynamic scattering test of drilling cuttings, HTHP dynamic sealing and plugging tests, ultra HTHP aging test and so on. The lab tests show that the new apparatus gains such advantages as novelty of the design, stability of the performance, accuracy and reliability of the experimental data and facility of the operation. Having overcome the defections of the old apparatuses, the new device can provide a new means of experimental researches for the evaluation of HTHP comprehensive performance of deep well drilling fluid.

Dynamical Simulation of High-Pressure Gas Kick in Ultra-Deepwater Riserless Drilling

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Liangjie Mao ◽  
Mingjie Cai ◽  
Qingyou Liu ◽  
Guorong Wang
Keyword(s):  
High Pressure ◽  
Return Rate ◽  
Influx Rate ◽  
Well Control ◽  
Hole Pressure ◽  
Bottom Hole Pressure ◽  
Dynamical Simulation ◽  
Bottom Hole ◽  
Gas Kick ◽  
Wellbore Pressure

Abstract During riserless drilling for ultra-deepwater gas wells, well control challenges induced by high-pressure gas kick will be faced. A two-phase flow model with consideration of high-pressure gas invasion during riserless drilling was proposed, and the model was proved to be more accurate for predicting high-pressure gas kick during riserless drilling by reproducing field data and comparison with published models. Then, a dynamical simulation of high-pressure gas kick in ultra-deepwater riserless drilling was presented. Results showed that during ultra-deepwater riserless drilling, the bottom hole pressure will be underestimated, while pit gain will be over-estimated without considering the gas acceleration effect. With the consideration of gas acceleration effect at high-pressure well bottom, the gas influx rate increases rapidly with the kick time and tends to be stable after a period of time as negative pressure difference at well bottom increases. During riserless drilling, according to the timeliness and effectivity of kick detection methods, pit gain is prior for kick detection, following bottom hole pressure, standpipe pressure, and return rate. Moreover, if early gas kick was not detected, the rapid increase in change rate of standpipe pressure and return rate can be regarded as an indicator, showing that gas is reaching mud line. Besides, the effects of shutoff time, drilling displacement, drilling fluid density increases, geothermal gradient, and reservoir permeability on kick indicators and wellbore pressure have been discussed. The research results could provide important theoretical bases and technical guidance for well control aspects of riserless drilling.

The Feasibility for Potassium-Based Phosphate Brines To Serve as High-Density Solid-Free Well-Completion Fluids in High-Temperature/High-Pressure Formations

SPE Journal ◽  
2018 ◽  
Vol 24 (05) ◽  
pp. 2033-2046 ◽  
Author(s):  
Hu Jia ◽  
Yao–Xi Hu ◽  
Shan–Jie Zhao ◽  
Jin–Zhou Zhao
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Oil And Gas ◽  
Pressure Coefficient ◽  
High Density ◽  
Well Drilling ◽  
Well Completion ◽  
Oil And Gas Resources ◽  
Completion Fluids ◽  
High Temperature High Pressure

Summary Many oil and gas resources in deep–sea environments worldwide are often located in high–temperature/high–pressure (HT/HP) and low–permeability reservoirs. The reservoir–pressure coefficient usually exceeds 1.6, with formation temperature greater than 180°C. Challenges are faced for well drilling and completion in these HT/HP reservoirs. A solid–free well–completion fluid with safety density greater than 1.8 g/cm3 and excellent thermal endurance is strongly needed in the industry. Because of high cost and/or corrosion and toxicity problems, the application of available solid–free well–completion fluids such as cesium formate brines, bromine brines, and zinc brines is limited in some cases. In this paper, novel potassium–based phosphate well–completion fluids were developed. Results show that the fluid can reach the maximum density of 1.815 g/cm3 at room temperature, which makes a breakthrough on the density limit of normal potassium–based phosphate brine. The corrosion rate of N80 steel after the interaction with the target phosphate brine at a high temperature of 180°C is approximately 0.1853 mm/a, and the regained–permeability recovery of the treated sand core can reach up to 86.51%. Scanning–electron–microscope (SEM) pictures also support the corrosion–evaluation results. The phosphate brine shows favorable compatibility with the formation water. The biological toxicity–determination result reveals that it is only slightly toxic and is environmentally acceptable. In addition, phosphate brine is highly effective in inhibiting the performance of clay minerals. The cost of phosphate brine is approximately 44 to 66% less than that of conventional cesium formate, bromine brine, and zinc brine. This study suggests that the phosphate brine can serve as an alternative high–density solid–free well–completion fluid during well drilling and completion in HT/HP reservoirs.

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