The Method And Application Of Contour's Drawing In Oil Field

The petroleum industry is one of the national pillar industries, it has a veryimportant position among them that the oil gas explores technology, its characteristic isa high investment, high output and high risky, explore one well will cost up to ten millionyuan , and the producing oil rate is less than 50% equally, improve oil explorationtechnologying has very high social and economic benefits. Oil exploration technology isinfering the geological structure and geology distribute parameters underground througha large amount of data that making use of various kinds of advanced scientific meansand methods to get, thus confirm reserves of petroleum , the position and form ofpetroleum rich collecting area ,etc., one of the important method is to draw out thegeological contours of the corresponding area.Because the underground geologicalstructure is extremely complicated, the data that needing dealing with is very enormous,in addition the data are distributed very uneven, so fully make use of the data processingability and graph processing function of the computer to draw the contours automatic isone of the efficiency important means to improve the efficiency of the data processing inthe oil gas exploring technology. So, studying the design and realization of contoursdrawing automatic , developing the corresponding application software, realizingcontours drawing automatic, has very important social value and economic worth .Draw the contour by hand is very slow, and the precision is low , apt to makemistakes. Utilizing the computer could overcome these insufficiently while drawing thecontour automatically. Generally ,there are three main courses on drawing the contourswith computer: Calculate the contours'level position; Look for the starting point andending point, follow the trail of all contours; Connect every contour and smooth the curve.In this paper, the data used for producing the contour are all dispersed data.According to distribution and quantity of the dispersed data in the area ,it is divide twokinds in dispersed datum network methods:Regular net and non-regular net. The formermeans that divides the area into a rectangle net according to certain interval , thereforeit's good for the regular border area; The latter means the triangular net and wantonquadrangle net mainly, it's good for the area of the wanton border . According to theneeds of reality of oil field production, this paper has adopted two kinds of methods todraw the contour respectively, namely: The net of the rectangle and triangular network.Drawing the contour with the net of the rectangle, the step is as follows:1,get numberical value of the grid points : The method to get numberical value of the gridpoints is a synthesis method, its basic thought is: estimate the trend-value of every gridpoints and dispersed points and the surplus-value of all the dispersed points withtrend-method, calculate the surplus-value of every grid point with distance-and-quotietymethod , trend-value add surplus-value is the estimate-value of grid points. This methodhas much advantages such as fast operation speed , strongly extrapolating ability andwide accommodation etc..2, look for the equivalence point: To any lines: if the attribute value of one point on theline is greater than the attribute value of the contour , and the attribute value of anotherpoint on the line is smaller than the attribute value of the contour , there must be aequivalence point on the line. Here p1p2 is a line , the attribute value of one point isp1.value, the attribute value of another point is p2.value, the attribute value of the contouris value , if (p1.value-value ) * (p2.value-value) <0, then there is a equivalence point onthe line p1p2 ; If (p1.value-value) * (p2.value-value)>,0,there is no equivalence point; If(p1.value-value) * ( p2.value-value) =0, then the contour will be through p1 or p2, such apoint will increase degree of difficulty that procedure deal with, in practical application,such equivalence point, add its value to a very small number value, in this way , have notonly will not influence the precision of drawing but also avoided the trouble while trailingthe contours.3, get coordinate value of equivalence point: setting dx as the interval of net in x direction,dy is a interval of net in y direction, if equivalence point exists at the line, coordinatevalue of equivalence point is :At the horizontal edgey = yMin + ( i + ySide[i][j] ) * dy;4, track the equivalence point: first , confirm the trend when the contour enters the net,only 4 kinds are possible: from bottom to top , from top to bottom , from left to right,andfrom right to left ; Secondly , confirm where to go out on one side after contour enter thenet.5, search the contour : As to not closing curve , beginning to search for from left to righton the bottom border, then on the left,the on the top ,on the right at last; For closing curve,need to scanning by each net line within the rectangle area, namely from left to Right andfrom bottom to top.Drawing contour with the triangular network ,the step is as follows:1, connect the triangular network : the method is insert point to the triangular net one byone, its key thought is: While adding one point to the net, find out the triangle whichincludes this point. If fall in the triangle ,connect this point with the three vertex of thetriangle, and send three sides of the triangle into the optimizing queue , optimizeaccording to two property of Delaunay triangular network ; If it is on the triangleedge,then delete the edge,set up two new edges again, and send other two edges orfour edges into the optimizing queue.2, look for the equivalence point: if the attribute value of contour is Z0, if (Zi-Z0)*(Zj-Z0)≤0,there is a equivalence points at the edge , if Zj-Z0 =0, then order Zi=Zi-ε,εis a very littlevalue.3, get coordinate value of equivalence point: use the following formula to get the ?X = Xi + X ? Xi j Z j ? Zi (Z0 ? Zi)coordinate value of equivalence point ??? ?Y Yj ?Yi ?? =Y + Z j ? Zi (Z0 ? Zi)4, track the equivalence point : Its step is as follows:1)Look for the contour starting point;2)Look for bordering on the unit by the edges altogether;3)Repeating (2), if can not find the edges altogether, and unit not in use, there is unit not...