Sum vector data correlating with a second vector layer [duplicate]

Sum vector data correlating with a second vector layer [duplicate] References This question already has an answer here: QGIS: Point to Polygon - multiple variables 2 answers There are a lot of questions very similar to mine, but I couldn\'t find one that accurately described what I want to do. I am working in QGIS. I have one vector layer which, among other attributes, has a production volume for oil wells. I have a second layer which represents townships. Some townships have five wells, some have none etc., all with different levels of production. I want to create a new layer which displays all the townships with a summation of the total production volume within the township. Can anyone think of an efficient way to do this? EDIT: I would also like to be able to the sum of the production volumes to the township layer. Thanks!