scholarly journals Laboratory Study on 210°C High Temperature and Salt Resistant Drilling Fluid

2021 ◽  
Vol 06 (03) ◽  
pp. 83-97
Author(s):  
Xintong Li ◽  
Qichao Cao ◽  
Li He ◽  
Shunyuan Zhang ◽  
Song Wang
Keyword(s):  
High Temperature ◽  
Laboratory Study ◽  
Drilling Fluid

Stimulation of Wells Damaged by Barite Present in Filter Cake or Scale

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Igor Ivanishin ◽  
Hisham A. Nasr-El-Din ◽  
Dmitriy Solnyshkin ◽  
Artem Klyubin
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Ethylenediaminetetraacetic Acid ◽  
Solid Phase ◽  
Barium Carbonate ◽  
Process Analysis ◽  
Drilling Fluid ◽  
Field Application ◽  
X Ray ◽  
Dissolution Efficiency

Summary High-temperature (HT) deep carbonate reservoirs are typically drilled using barite (BaSO4) as a weighting material. Primary production in these tight reservoirs comes from the network of natural fractures, which are damaged by the invasion of mud filtrate during drilling operations. For this study, weighting material and drilling fluid were sampled at the same drillsite. X-ray diffraction (XRD) and X-ray fluorescence analyses confirmed the complex composition of the weighting material: 43.2 ± 3.8 wt% of BaSO4 and 47.8 ± 3.3 wt% of calcite (CaCO3); quartz and illite comprised the rest. The drilling fluid was used to form the filter cake in a high-pressure/high-temperature (HP/HT) filter-press apparatus at a temperature of 300°F and differential pressure of 500 psig. Compared with the weighting material, the filter cake contained less CaCO3, but more nondissolvable minerals, including quartz, illite, and kaolinite. This difference in mineral composition makes the filter cake more difficult to remove. Dissolution of laboratory-grade BaSO4, the field sample of the weighting material, and drilling-fluid filter cake were studied at 300°F and 1,000 to 1,050 psig using an autoclave equipped with a magnetic stirrer drive. Two independent techniques were used to investigate the dissolution process: analysis of the withdrawn-fluid samples using inductively coupled plasma-optical emission spectroscopy, and XRD analysis of the solid material left after the tests. The dissolution efficiency of commercial K5-diethylenetriaminepentaacetic acid (DTPA), two K4-ethylenediaminetetraacetic acid (EDTA), Na4-EDTA solutions, and two “barite dissolvers” of unknown composition was compared. K5-DTPA and K4-EDTA have similar efficiency in dissolving BaSO4 as a laboratory-grade chemical and a component of the calcite-containing weighting material. No pronounced dissolution-selectivity effect (i.e., preferential dissolution of CaCO3) was noted during the 6-hour dissolution tests with both solutions. Reported for the first time is the precipitation of barium carbonate (BaCO3) when a mixture of BaSO4 and CaCO3 is dissolved in DTPA or EDTA solutions. BaCO3 composes up to 30 wt% of the solid phase at the end of the 6-hour reaction, and can be dissolved during the field operations by 5 wt% hydrochloric acid. Being cheaper, K4-EDTA is the preferable stimulation fluid. Dilution of this chelate increases its dissolution efficiency. Compared with commonly recommended solutions of 0.5 to 0.6 M, a more dilute solution is suggested here for field application. The polymer breaker and K4-EDTA solution are incompatible; therefore, the damage should be removed in two stages if the polymer breaker is used.

scholarly journals Laboratory Study on Core Fracturing Simulations for Wellbore Strengthening

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Biao Ma ◽  
Xiaolin Pu ◽  
Zhengguo Zhao ◽  
Hao Wang ◽  
Wenxin Dong
Keyword(s):  
Bearing Capacity ◽  
Laboratory Study ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
The Core ◽  
Fracture Pressure ◽  
Fluid Systems ◽  
Fracturing Process ◽  
Wellbore Strengthening

The lost circulation in a formation is one of the most complicated problems that have existed in drilling engineering for a long time. The key to solving the loss of drilling fluid circulation is to improve the pressure-bearing capacity of the formation. The tendency is to improve the formation pressure-bearing capacity with drilling fluid technology for strengthening the wellbore, either to the low fracture pressure of the formation or to that of the naturally fractured formation. Therefore, a laboratory study focused on core fracturing simulations for the strengthening of wellbores was conducted with self-developed fracture experiment equipment. Experiments were performed to determine the effect of the gradation of plugging materials, kinds of plugging materials, and drilling fluid systems. The results showed that fracture pressure in the presence of drilling fluid was significantly higher than that in the presence of water. The kinds and gradation of drilling fluids had obvious effects on the core fracturing process. In addition, different drilling fluid systems had different effects on the core fracture process. In the same case, the core fracture pressure in the presence of oil-based drilling fluid was less than that in the presence of water-based drilling fluid.

scholarly journals Experimental Investigation of the Rheological Behavior of an Oil-Based Drilling Fluid with Rheology Modifier and Oil Wetter Additives

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4877
Author(s):  
Mobeen Murtaza ◽  
Sulaiman A. Alarifi ◽  
Muhammad Shahzad Kamal ◽  
Sagheer A. Onaizi ◽  
Mohammed Al-Ajmi ◽  
...  
Keyword(s):  
High Temperature ◽  
Zeta Potential ◽  
Hot Rolling ◽  
Emulsion Stability ◽  
Drilling Fluid ◽  
Temperature Tolerance ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Before And After ◽  
Rheology Modifier

Drilling issues such as shale hydration, high-temperature tolerance, torque and drag are often resolved by applying an appropriate drilling fluid formulation. Oil-based drilling fluid (OBDF) formulations are usually composed of emulsifiers, lime, brine, viscosifier, fluid loss controller and weighting agent. These additives sometimes outperform in extended exposure to high pressure high temperature (HPHT) conditions encountered in deep wells, resulting in weighting material segregation, high fluid loss, poor rheology and poor emulsion stability. In this study, two additives, oil wetter and rheology modifier were incorporated into the OBDF and their performance was investigated by conducting rheology, fluid loss, zeta potential and emulsion stability tests before and after hot rolling at 16 h and 32 h. Extending the hot rolling period beyond what is commonly used in this type of experiment is necessary to ensure the fluid’s stability. It was found that HPHT hot rolling affected the properties of drilling fluids by decreasing the rheology parameters and emulsion stability with the increase in the hot rolling time to 32 h. Also, the fluid loss additive’s performance degraded as rolling temperature and time increased. Adding oil wetter and rheology modifier additives resulted in a slight loss of rheological profile after 32 h and maintained flat rheology profile. The emulsion stability was slightly decreased and stayed close to the recommended value (400 V). The fluid loss was controlled by optimizing the concentration of fluid loss additive and oil wetter. The presence of oil wetter improved the carrying capacity of drilling fluids and prevented the barite sag problem. The zeta potential test confirmed that the oil wetter converted the surface of barite from water to oil and improved its dispersion in the oil.

Meeting Drilling Fluid Challenges in Gulf of Thailand Ultra High Temperature Exploration Wells

2014 ◽  
Author(s):  
Kerati Charnvit ◽  
Fransiskus Huadi ◽  
Chakkrawut Promkhote ◽  
Catalin Aldea ◽  
David Power ◽  
...  
Keyword(s):  
High Temperature ◽  
Drilling Fluid ◽  
Gulf Of Thailand ◽  
Ultra High Temperature

Nanoemulsion with Controlled Rheology under Different Temperature for Effective Removal of Oil-based Drilling Fluid in Offshore Drilling

2021 ◽  
Author(s):  
Renzhou Meng ◽  
Chengwen Wang ◽  
Xiliang Dong ◽  
Chao Xiong
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Drilling Fluid ◽  
Offshore Drilling ◽  
Emulsion Droplets ◽  
Effective Removal ◽  
Engineering Requirement ◽  
Important Means ◽  
The Stability

Abstract Oil-based drilling fluid (OBDF) is an important means for offshore drilling, but it would affect the cementing quality. Nanoemulsions shows potential for OBDF removal, but how to prepare nanoemulsion meeting the engineering requirement is lack of good understanding. Moreover, nanoemulsions usually behave badly under low/high temperature, which would restrict the application. Revealing removal mechanisms of nanoemulsion and improving nanoemulsion stability at different temperature are of great significance. The nanoemulsion could rapidly spread on the wellbore surfaces, cause the adhering OBDF to curl into little droplets, and solubilize the removed OBDF. The removal efficiency can reach more than 98%. Low temperature and higher concentration of dispersed phase both increased the viscosity of nanoemulsions stabilized by surfactants. PEGs can induce the bridging of emulsion droplets at low temperature, leading to significant increase of nanoemulsions viscoelasticity at low temperature (around 5°C). To control the rheological properties of nanoemulsions, a hydrophobic association polymer, HAAP, was proposed. Nanoemulsions containing HAAP does not gel at low temperature (< 15°C). And the viscoelasticity of nanoemulsions increased slightly when the temperature is higher than 70°C because of the thermoassociating behavior of polymer, which can ensure the stability of the nanoemulsions at high temperature. This paper is helpful to establish a generic route for preparing nanoemulsions with controlled rheological properties under different temperature, which is benefit for their applications in offshore.

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