Formation Producing Characteristics research Laboratory

At present Burintekh, Ltd is major Russian engineering and service Company which provides oil-and-gas production enterprises with high quality rock destruction tools, technologies and offers complex of services: Bit service; Directional and horizontal drilling service, including telemetric systems; Downhole drilling motors runs; Drilling mud service; Service on milling window in casing string; Core recovery including isolated core; Reamers runs; Jars and BHA parts rent.

Drilling Mud Department Center of Training and Professional Advancement Regional Representatives Regional Projects Drilling Mud Laboratory Core Test Laboratory

Drilling Mud Laboratory Burintekh, Ltd drilling mud laboratory represents scientific and research basis with full research cycle on making and implementation of new perspective developments in the sphere of drilling fluids. LABORATORY DEVELOPMENTS New processable systems of drilling fluids on water and hydrocarbon basis. Mud systems for works in excessive temperature conditions, salt aggression and etc. Process liquids for works in abnormally high and low formation pressure conditions. Special fluids for chemical cleaning of bottom-hole formation zone; Multi-functional additives to drilling fluids which repellent reservoir surface, reduce stickiness, increasing ROP, and etc.

Formation Producing Characteristics research Laboratory With the help of experimental unit FDS-350 in laboratory conditions the nets actions are carried out: Examination of invasion; Static and dynamic filtrating tests; Experimental selection of colmatant in conditions equal to reservoir conditions; Estimation and minimization of mud negative effect to productive reservoir; Испытания влияния процессов кислотной или иной обработки на образцы продуктивного пласта при пластовом давлении и температуре. At creating new drilling mud compositions much attention is given to quality of primary revelation of producing horizon and saving its reservoir properties.

Special researches of core for quantitative estimation of formation damage in the result of penetration into it of drilling fluid on FDS- 350 facility Usually laboratory researches of displacement of productive formation characteristics are made by injection of damage liquid along core axis of known permeability. Formation of cake is happened, and after this the decrease of permeability to oil is measured. Unfortunately this procedure does not model drilling conditions accurately. For full modeling is necessary that damage fluid would flow tangentially to the face of core but not through it. For tests of influence of drilling fluid to productive formation in real field conditions by means of filtration of fluid tangentially to face of core is used special core holder with washing of core face. Drilling fluid circulates and penetrates in core at given pressure decrease, which is expected in real conditions.

Core holder with washing of core face the figure shows core holder, which is used in core testing. In core holder are placed reams with diameter 30 mm and length from 50 to 300 mm. In testing is provided all-around compression of formation by pump socket 10 and piston 16. Holes for recirculation of drilling fluid 13 allows to reproduce washing of formation by upflow in well. Enter and exit of formation fluid and monitoring of filtrate 11 and 19 allow to control filtrate volume during influence by drilling fluid and oil volume during modeling stimulation in well. In researching of long (compound) core samples with the help of ports for air release chamber press diff indicator 9, placed longwise core sample, is calculated change of permeability along apical axis of core.

Backpressure valve Is purposed for maintenance of intended formation pressure Design features of FDS-350 facility Drilling fluid recycle pump tangentially core face

Two cylinder pump for injection fluids Pump is placed outside of airswitch and purposed for injection of liquid in the fixed value of debit. This pump is made for compliance with requirements of any attachments in which sensitive pressure change, low rate and volume. Pump provides continuous flow without pulsing in wide range of pressures and works in environmental temperature. Pump controlling is made from computer with the help of specially designed software.

Software for registration of changes, control and creating reports registration of changes like temperature, pressure, pressure decrease, volume and debit. Continuous mapping of results graphically. recording data in computer for further processing. Facility control, displaying of system general condition and each option value. Providing with feedback with researcher.

Standard test procedures I.From full size core, recovered during drilling well under Russian State Standard «General requirements to core recovery and preparing samples for defining of collecting properties» is made cylindrical sample with necessary geometrical sizes. For drilling out core samples is used floor machine For cutting core samples is used cutoff machine

Standard test procedures II.Formation core sample before defining its filtrating parameters is subject toclening from hydrocarbons in Soxhlet apparatus. Also is possible to define oil and water saturation of rock. Soxhlet apparatus For changing oil and water saturation is used Din-Stark apparatus.

Standard test procedures III.Under State Standard «Method of defining of absolute permeability» is defined the absolute permeability of core samples. IV.Sample with known absolute permeability pervades with salt water (synthetic brine) with given mineralizing. Under State Standard «Method of defining effective porosity» is defined open porosity of sample. Apparatus for defining permeability of core samples upon gas «Darcymeter» For defining open porosity under State Standard is used analytic balance with set for hydrostatic weighing.

Standard test procedures V.For researches of displacement of formation characteristics the sample is placed in «FDS – 350» facility made by «Vinci technologies». 1.First test is made for defining reference fluid permeability of core before action on it by drilling fluid. This permeability value is used as reference in estimation of impact assessment of drilling fluid to formation. 2.After above said test core is induced by drilling fluid form the side of well. Pumping is made from well to layer with dynamic circulation of drilling fluid longwise surface of core and with static repression to layer, expected in drilling. 3.After core test on inducing to it with drilling fluid, analogous with test, shown it item 1, the test on fluid inflow is made. At the beginning with relatively low oil inflow the pressure measurement is made in which the removal of filter cake is happened. Then again the calculation of oil permeability of core is made. 4.In case if the cementing with further completion is planned, core holder is dismantled and core sample is taken out. From the contaminated side of sample is cut off 10mm (simulation of completion of productive horizon). The test for fluid inflow is made and reverse oil inflow of core after removal of colmatation zone is measured.

Typical test results I.Mud-loss dynamics on exposure to core. On the results of measurement there is made the diagram of dependence of filtration of drilling mud from time Vф = f(t), combined with diagram of changes of pressure decrease on core - repression. Using the geometric formulas the depth of penetration of drilling mud is calculated.

Typical test results II.Filtrate cake removal Diagram shows results of defining of pressure, in which filter cake removal is happened. These results are used in calculation of needed depression in removal of clay cake during production recovery by means of machine applications (or in natural recovery mechanism).

Typical test results III.Defining results of core permeability Initial permeability before exposure to core with drilling mud is shown in left side of diagram, oil permeability after exposure – in middle section, and permeability after colmatation zone removal or acid treatment – in right side. This diagram shows also depression, which was used during tests. Results of permeability defining before and after exposure to core (which are made during above said core tests) are shown as diagram. Vertical lines are boards between groups of results of measurements before contamination with mud, after contamination and simulation of completion.

Typical test results IV.Researching results on drilling mud effect to layer. Note: k1неф – initial permeability of core sample; k2кольм – core sample permeability after mud effect; k3ост – core sample permeability after completion simulation; βкольм – oil permeability reviving after mud effect with reference to oil permeable formation before effect; Lфильтр – depth of invasion of fluid filtrate for killing in core sample; Р1кольм – oil influx stimulation initiation pressure after mud effect; βост – reviving of permeability after simulation after completion with reference to oil permeability of formation before mud effect. Sample k 1 неф, мД k 2 кольм, мД k 3 ост, мД β кольм,% L фильтр, мм Р отрыва, psi / атм β ост,% k абс = 537 мД ,238919,2/1,393,9

As is known drilling mud for tailing-in must minimally contaminate oil-filled formation during its drilling out and lead to minimal decreasing of oil permeability. For recommending the usage of drilling fluid for tailing- in it is necessary to establish its influence on lowering of oil permeability. This research includes the range of laboratory experiments with formation and testing mud fluid. All necessary researches are made in formation Producing Characteristics research Laboratory Burintekh, Ltd. Conclusion