Loss Circulation and Formation Damage Control on Overbalanced Drilling With Different Formulations of Water Based Drill-In Fluids on Sandstone Reservoir

2012 ◽  
Author(s):  
Leandro F. Lopes ◽  
Bruno O. Silveira ◽  
Rosângela B. Z. L. Moreno
Keyword(s):  
Reverse Flow ◽  
Damage Control ◽  
Fluid Management ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Reservoir Water ◽  
Well Productivity ◽  
Water Based ◽  
Permeability Impairment ◽  
Productivity Ratio

The oil well drilling should not damage formation, mainly the interest region: the reservoir. Drilling without damaging the reservoir is a hard challenge, and therefore the development of technologies and optimization process, including, for example, the design of fluids in order to minimize damage, is been stimulated. Drilling fluids may interact with reservoir rocks resulting on permeability impairment, which reduces well productivity. It has been reported that a detailed fluid management plan can help to minimize formation damage and improve well productivity. This work is focused on formation damage analysis due to drilling fluids invasion in high permeability sandstone oil reservoir. Water-based fluids were prepared with the following components: distilled water, salt (NaI), polymer (Partially Hydrolyzed Polyacrylamide - HPAM, and Xanthan Gum - XG) and clay (Bentonite). Samples were submitted to an invasion process, simulating an overbalanced drilling, and to an oil reverse flow, simulating oil production beginning. Results showed that all fluids containing clay presented less deep invasion than the fluids prepared with polymer only. Moreover, clay concentration influenced on permeability impairment and productivity ratio return results. HPAM fluids, when injected, invaded more deeply the samples than XG fluids, but productivity ratio return was also higher.

Petrology and formation damage control, Upper Cretaceous sandstone, offshore Gabon

Clay Minerals ◽  
1986 ◽  
Vol 21 (4) ◽  
pp. 781-790 ◽  
Author(s):  
E. D. Pittman ◽  
G. E. King
Keyword(s):  
Upper Cretaceous ◽  
Damage Control ◽  
Salt Diapir ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Intergranular Porosity ◽  
Flow Formation ◽  
Sensitivity Tests ◽  
Formation Damage Control ◽  
Permeability Impairment

AbstractThe subarkosic-sublitharenitic Upper Cretaceous sandstone, which has up to 30% porosity and 585 md permeability, produces on salt diapir structures in the Oguendjo West Block, offshore Gabon. The porosity consists of 68% intergranular porosity of primary and secondary origin, 17% secondary intragranular and moldic porosity, and 15% microporosity. A microcrystalline quartz druse, which was derived from alteration of lithic fragments, coats framework grains and retards the development of syntaxial quartz overgrowths. Other cements are patchy ankerite (0·3–13·7 vol%) and kaolinite, which also occurs as a replacement of framework grains. The total kaolinite content ranges from 1·8 to 8·2 vol%. Kaolinite and remnants of altered and partially dissolved lithic fragments are susceptible to movement with fluid flow. Formation sensitivity tests showed that the kaolinite-rich sandstone was stable to 2% NaCl water, but introduction of freshwater caused permeability impairment. Acid treatment to remove damage produced sporadic results. Injection of HCl raised the permeability temporarily, indicating that fines were still being liberated within the pore network. Injection of HCl/HF immediately reduced permeability through partial disaggregation of the rock. Plugging of the formation face by drill mud also damages the reservoir. Reversal of flow at high pressure differentials will remove formation damage produced by face plugging. A guideline for this process established in the laboratory is to backflow with a pressure differential at least as high as the overbalance used in drilling. The combination of oil-based drilling fluids and underbalanced perforating with filtered diesel in the wellbore should eliminate most formation damage in this reservoir.

scholarly journals Experimental study on thermal, rheological and filtration control characteristics of drilling fluids: effect of nanoadditives

2020 ◽  
Vol 75 ◽  
pp. 36
Author(s):  
Erfan Veisi ◽  
Mastaneh Hajipour ◽  
Ebrahim Biniaz Delijani
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Drill Bit ◽  
Rheological Characteristics ◽  
Cu Nanoparticles ◽  
Water Based

Cooling the drill bit is one of the major functions of drilling fluids, especially in high temperature deep drilling operations. Designing stable drilling fluids with proper thermal properties is a great challenge. Identifying appropriate additives for the drilling fluid can mitigate drill-bit erosion or deformation caused by induced thermal stress. The unique advantages of nanoparticles may enhance thermal characteristics of drilling fluids. The impacts of nanoparticles on the specific heat capacity, thermal conductivity, rheological, and filtration control characteristics of water‐based drilling fluids were experimentally investigated and compared in this study. Al2O3, CuO, and Cu nanoparticles were used to prepare the water-based drilling nanofluid samples with various concentrations, using the two-step method. Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) were utilized to study the nanoparticle samples. The nanofluids stability and particle size distribution were, furthermore, examined using Dynamic Light Scattering (DLS). The experimental results indicated that thermal and rheological characteristics are enhanced in the presence of nanoparticles. The best enhancement in drilling fluid heat capacity and thermal conductivity was obtained as 15.6% and 12%, respectively by adding 0.9 wt% Cu nanoparticles. Furthermore, significant improvement was observed in the rheological characteristics such as the apparent and plastic viscosities, yield point, and gel strength of the drilling nanofluids compared to the base drilling fluid. Addition of nanoparticles resulted in reduced fluid loss and formation damage. The permeability of filter cakes decreased with increasing the nanoparticles concentration, but no significant effect in filter cake thickness was observed. The results reveal that the application of nanoparticles may reduce drill-bit replacement costs by improving the thermal and drilling fluid rheological characteristics and decrease the formation damage due to mud filtrate invasion.

scholarly journals Damage Mechanism of Oil-Based Drilling Fluid Flow in Seepage Channels for Fractured Tight Sandstone Gas Reservoirs

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Peng Xu ◽  
Mingbiao Xu
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Damage Mechanism ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Stabilization Effect ◽  
Potential Damage ◽  
Physical And Chemical

Oil-based drilling fluids (OBDFs) have a strong wellbore stabilization effect, but little attention has been paid to the formation damage caused by oil-based drilling fluids based on traditional knowledge, which is a problem that must be solved prior to the application of oil-based drilling fluid. For ultradeep fractured tight sandstone gas reservoirs, the reservoir damage caused by oil-based drilling fluids is worthy of additional research. In this paper, the potential damage factors of oil-based drilling fluids and fractured tight sandstone formations are analyzed theoretically and experimentally. The damage mechanism of oil-based drilling fluids for fractured tight sandstone gas reservoirs is analyzed based on the characteristics of multiphase fluids in seepage channels, the physical and chemical changes of rocks, and the rheological stability of oil-based drilling fluids. Based on the damage mechanism of oil-based drilling fluids, the key problems that must be solved during the damage control of oil-based drilling fluids are analyzed, a detailed description of formation damage characteristics is made, and how to accurately and rapidly form plugging zones is addressed. This research on damage control can provide a reference for solving the damage problems caused by oil-based drilling fluids in fractured tight sandstone gas reservoirs.

The "U-Type" Wells History of Fuzzy Ball Drilling Fluids for CBM Drilling in China

2013 ◽  
Vol 748 ◽  
pp. 1273-1276 ◽  
Author(s):  
Ben Guang Guo ◽  
Li Hui Zheng ◽  
Shang Zhi Meng ◽  
Zhi Heng Zhang
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Ordos Basin ◽  
Coal Bed ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Horizontal Section ◽  
Lost Circulation ◽  
Well Bore Stability ◽  
Formation Damage Control

The fuzzy ball drilling fluids have been developed on the basis of the circulation foam and Aphron to control lost circulation effectively. There are some difficulties in drilling U-type well, such as well-bore stability, cutting carrying problem, large torque and friction at the horizontal section, and formation damage to coal-bed. The objective of this paper was to show some applications of fuzzy ball drilling fluids on U-type wells of the Ordos Basin and prove the superiority of fuzzy ball drilling fluid in CBM drilling. To the three mentioned cases, the density of fuzzy ball drilling fluid was 0.90~1.18g/cm3, the funnel viscosity was 45~72s, the dynamic shear force was 12~19 Pa, the PV was 13~19mPa·s and the pH was ranged from 7 to 9. To use the fuzzy ball drilling fluids, the average ROP increased above 10% with no borehole complexity, such as stuck pipe, hole enlargement causing poor cleaning and etc. These cases reflected excellent properties of the fuzzy ball drilling fluids including effectively sealing, good carrying and suspension ability, formation damage control and compatible weighted by inert materials. Furthermore, the fuzzy ball drilling fluids will not affect BHA tools like motors and MWD in CBM drilling.

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