A novel high pressure, high temperature vessel used to conduct long-term stability measurements of silicon MEMS pressure transducers

Abstract Formation damage by the drill-in fluid has been identified as a major risk for the Dvalin HT gas field. To ensure the long-term stability and mobility of the mud even after an extended suspension time between drill-in and clean-up of the wells, a novel static aging test under downhole temperature and high pressure was conducted. Experiments have shown that the downhole stability is commonly underestimated when the surrounding pressure is lower than in the field. Thus, a high-pressure cylinder was used in vertical orientation in a heating oven with a pressure pump regulating the pressure up to 200 bar. The reservoir section was drilled with the optimized organo-clay-free oil-based drilling fluid (OCFOBDF) specified in the qualification phase. Tracers in the lower completion were used to identify clean-up from the upper high-permeability streak and the deeper (relatively lower) high-permeability streak. Due to extended wait on weather after drilling and completion of the first of the four wells, the lag time until clean-up was almost 11 weeks (74 days). It could be experimentally shown that the qualified OCFOBDF system weighted with micron sized barite remains mobile without phase separation even after static aging at 160 °C and 200 bar for the maximum estimated lag time between drilling and clean-up of 3 months. The absence of a gas cap in the set-up also better represents downhole conditions in the reservoir section and has shown that it improves the fluid´s stability. The clean-up of the well was successful with a maximum flowrate of 3.0 MM Sm3/d. Analysis of the tracers has proven that clean-up was successful for the entire reservoir section, including the deeper part. It could be concluded that in alignment with the lab tests that the mud fulfilled its requirement to be mobile even up to three months. Because of the superior properties, settling of solids (bridging and weighting material) could be avoided, resulting in no blockage of the (lower part of the) reservoir. The use HPHT aging has been the key to proving the long-term stability and mobility of the combined Drill-In and Completion Fluid. This technique falls outside of current API RP testing practices but is believed to be highly beneficial for qualification of fluids that will be left in the lower completion for long periods, especially in open hole completions under high temperature and pressure.

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Long-term stability of the Io high-temperature plasma torus

The Astrophysical Journal ◽

10.1086/163304 ◽

1985 ◽

Vol 294 ◽

pp. 369 ◽

Cited By ~ 39

Author(s):

H. W. Moos ◽

T. E. Skinner ◽

S. T. Durrance ◽

P. D. Feldman ◽

M. C. Festou ◽

...

Keyword(s):

High Temperature ◽

Temperature Plasma ◽

Term Stability ◽

Long Term Stability ◽

High Temperature Plasma ◽

Plasma Torus

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A Novel Water-Based Drilling Fluid Tailored for Challenging Slanted HTHP Wells

10.2118/202178-ms ◽

2021 ◽

Author(s):

Vaughn Reza Traboulay ◽

Tint Htoo Aung ◽

Cedric Manzoleloua ◽

Balakrishnan Panamarathupalayam ◽

Carmelo Arena ◽

...

Keyword(s):

High Temperature ◽

Drilling Fluid ◽

Synthetic Polymer ◽

Term Stability ◽

Long Term Stability ◽

High Temperature Water ◽

Water Based ◽

Static Conditions ◽

Temperature Water

Abstract High-temperature water-based drilling fluid systems hold several advantages over synthetic based systems from financial and environmental viewpoints. However, most conventional water-based systems start to become unstable at temperatures above 300 degF. This paper details the design and implementation of A Novel Water-Based Drilling Fluid that meet these temperature stability requirements. The newly developed high-temperature water-based system discussed in this paper utilizes a custom-made branched synthetic polymer that exhibits superior rheological properties and fluid loss control as well as long term stability above 400 degF. The branched synthetic polymer is compatible with most oilfield brines and maintains excellent low-end rheology necessary for hole cleaning and solids suspension under high-temperatures and pressures. Under static conditions, the high-temperature fluid shows no gelation resulting in lower swab surge pressures while the stability of the highly branched synthetic polymer and enhanced rheological profile minimize sag. To drill a challenging exploration well, a Middle East client required a cost-effective drilling fluid system which remains stable under static temperatures expected to exceed 375 degF. The long-term stability of the system was critical for successful wireline logging operations. In addition, the system was required to provide shale inhibition, hydrogen sulfide suppression and sufficient density (above 16.5 lbm/galUS) to maintain well integrity while drilling through anticipated high-pressure zones. The challenging intermediate (12.25-in and 8.375-in) and reservoir (6-in) sections were successfully drilled and evaluated using this new branched synthetic polymer-based system. Fluid property trends and system treatments will be detailed alongside thermal stability data for extended periods required for wireline logging (up to 9 days static). This paper will discuss how proper laboratory design of the high-temperature water-based system was translated to excellent field performance and will indicate how this technology can be utilized for future campaigns in the region and worldwide.

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Short and Long Term Stability Measurements Using Automatic Data Recording System

10.1109/freq.1973.199990 ◽

1973 ◽

Cited By ~ 3

Author(s):

J.A. Bowman

Keyword(s):

Recording System ◽

Data Recording ◽

Automatic Data ◽

Term Stability ◽

Long Term Stability ◽

Short And Long Term ◽

Stability Measurements

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Study on Comprehensive Measures of Long-Term Stable Dense Oil Reservoir

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.416-417.1904 ◽

2013 ◽

Vol 416-417 ◽

pp. 1904-1907

Author(s):

Yong Wang ◽

Dong Bo Shao ◽

Hong Jun Lu ◽

Xiao Bin Lu

Keyword(s):

High Pressure ◽

Effective Means ◽

Water Injection ◽

Oil Reservoir ◽

Formation Pressure ◽

Term Stability ◽

Long Term Stability ◽

Pressure Injection ◽

Tight Reservoir

water injection development is an effective means of tight reservoir to maintain formation energy, and high formation pressure is the basis of reservoir maintain a long-term and stable, therefore, give enough water injection, so as to maintain high pressure is the key to maintain the long-term stability of the reservoir. Liu Maoyuan block Changqing Oilfield is a typical part of tight sandstone reservoir, water injection wells long is not up to the demand of injection, after fracturing, acidizing by invalid injection measures, is not conducive to long-term and stable block. Therefore, research on comprehensive countermeasures of long-term stability of dense oil reservoir. Through the research and development of new antihypertensive drag reduction agent for the overall pressure on block; select suitable for dense reservoir single well stimulation measures and local boosting measures, measures ineffective wells and local abnormal pressure injection is difficult to solve the problem of the cause, to maintain formation pressure. A good result has been obtained by field test, effectively solve the tight reservoir by high-pressure injection resulted in not long-term stability problems, and provides a new idea and reference for solving dense reservoir long-term stability problem.

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